FAQs

USG Cavity Shaft Wall can be used in elevator and mechanical shafts, air ducts, stairwells, and areas where wall construction is only available from one side. In addition, USG Cavity Shaft Wall can be used to provide horizontal protection for corridor ceilings, underside of stairwells, and other applications.

USG always recommends shot blasting, sand blasting, or scarifying a floor prior to installations of our self-leveling products. To decide whether mechanical preparation of substrate is required or not, the concrete substrate must be thoroughly assessed for its quality and tensile strength over the entire pour area. The assessment of concrete tensile strength must be made in its existing state without the removal of any foreign material that may be present on the concrete surface. Simple visual appearance of concrete substrate as strong and solid does not necessarily guarantee that the concrete substrate is free of impurities and has the right tensile strength.

A weak or degraded concrete surface layer must be removed mechanically to provide a solid base. Concrete exhibiting signs of laitance (a layer of weak material on the concrete surface either visible or invisible), scaling, spalling, crumbling or delamination must be mechanically removed to achieve a solid and clean substrate. Prior to installation of the underlayment, mechanically profile concrete subfloor to a minimum of CSP 3, in accordance with the industry standards as outlined in International Concrete Repair Institute (ICRI) Technical Guideline No. 310.2 Selecting and Specifying Concrete Surface Preparation for Sealers, Coatings, and Polymer Overlays.

Use mechanical removal methods such as shot blasting, scarifying or diamond grinding to clean and prepare the concrete subfloor contaminated with adhesives, asphalt or oil. Shot-blasting is the preferred method of mechanically profiling and preparing the concrete subfloor for the application of USG self-leveling underlayments.

USG makes three Clean Room® panels for use in these applications. USG Clean Room® Class 100/ISO Class 5, USG Clean Room® 10M-100M and USG Sheetrock® Brand Lay-In Ceiling Panel Clean Room™ are best for a clean room application.

While not tested by UL, the system has been tested for fire and is covered for use throughout the United States. The fire test number is WHI 495-PSH-0154/0167 and report number is AER-09038 available at www.p-e-i.com.

Do not exceed 16 inches on center.

For most interior applications, Durock® Brand Cement Board Panels are not affected by water and do not need to be waterproofed. Durock® is water durable but not waterproof. If you're looking for added protection to water sensitive material behind the Durock®, you may consider adding a waterproofing membrane. TCNA guidelines recommend the use of a waterproof membrane in interior wet areas. 

For exterior applications, consult your design professional as vapor permeance is climate dependent. 

The design of structural members containing fire damper assemblies is normally the responsibility of the fire damper manufacturer, and not USG. This is for proper operation of the fire damper during a fire.

Page 469 of regulation 29 CFR 1926.1153. 

Yes. If the main tees, cross tees and hanger wires are properly sized and spaced to carry the plaster load and only Red Top®; Structo-base® gypsum basecoat plaster is used for the scratch and brown coats.

The MVER tolerances are 5 lbs./1,000 s.f./24 hours.

Weight is a major difference, but Sheetrock® Brand UltraLightweight All Purpose Joint Compound also has great workability, improved slip that makes it easy to wipe down and work with hand tools, very good wet tack that holds the tape in place securely so the finisher can run long strings of tape before coming back to wipe it in. The ultra light weight and wet tack also combine to keep the compound from dripping, thus reducing the time required to clean compound off the floors. Good open time is another benefit, enabling contractors to smooth a joint without the product drying prematurely and causing roll ups or tearing.

Flat ceilings constructed of gypsum board that are screw-attached to suspension members that support a ceiling on one level extending from wall to wall, are generally exempt from acoustical seismic construction requirements such as: perimeter end wall clearance, perimeter hanger wires, horizontal restraint and vertical splay bracing. This is due to the diaphragm strength achieved by screw-attached gypsum board. Gypsum board ceilings that do not extend perimeter to perimeter, or have multiple levels, may require seismic bracing depending on the local code interpretation.

USG Durock™ Brand Performance Flooring products are primarily meant to be used over properly prepared concrete. The products can also be used with metal lath over engineer-approved, APA-Rated exterior glue plywood or oriented strand board (OSB) (i.e., APA-Rated Exterior or Exposure 1 panels) wood subfloors following the Tile Council of North America's F-185-11 specification at a minimum ½ in. depth.

Yes. It is possible to substitute studs as long as the stud is of thicker gauge, size, or both.

Over time stains settle into a wall or ceiling. When that area is retextured the stains photograph through causing a yellowing or browning effect. The best way to prevent staining is to apply a stain blocker, primer, and sealer.

The silica rule is a jobsite regulation designed to protect workers from all RCS exposures above 50 µg/m³, which is the PEL as defined by OSHA. Under normal jobsite conditions, industrial hygiene testing conducted by a third-party, indicated that the sanding of Sheetrock® Brand ready-mixed joint compound, unless otherwise specified on packaging and within the SDS, does not contain RCS above the PEL. 

Just like the other competitive products in the market today, our self-leveling underlayments do contain a small amount of gypsum that enhances the strength and dimensional characteristics of the products.

Yes. USG has a wide selection of floor ceiling assemblies that have been tested for acoustical performance with the Drywall Suspension System. For more information regarding a specific design, please see USGDesignStudio.com.

Class A signifies that a panel attained a flame spread index of 25 or less (based on 100 for untreated red oak) when tested in accordance with the Standard ASTM E 84. The Firecode® brand signifies that the panel has been classified as a protective membrane in a floor-ceiling or roof-ceiling assembly in accordance with the Standard ASTM E 119. All Firecode® protective membranes offered by USG have attained a Class A rating.

USG has been manufacturing quality building material products for 110 years. We have been selling cement-based products for more than 30 years and have been making underlayment products since the 1970’s. We have an industry-leading R&D center in Libertyville, Illinois, and have several members of our technical staff who have PhD’s in cement-related fields.

Fly ash often is used as a filler in concrete. When used at excessive levels, fly ash and concrete has been cited as one of the reasons for excessive moisture in concrete slabs.

In Durock™ EcoCap™ Self-Leveling Underlayment, the fly ash is not used as filler but rather as a source of aluminum and silicon in the geopolymer reaction that takes place. In this case, the fly ash contributes significantly to the strength, self drying and setting characteristics of the product due to the geopolymer reaction.

Our Sheetrock® Brand Mold Tough® Abuse-Resistant VHI Firecode® Core Panels meet ASTM C1396 level 3 (highest) performance for soft and hard body impact resistance.

For ceiling with framing of 16 inches or closer, the spacing is 7 inches or closer for nails and 12 inches or closer for screws. Fastener spacing for walls are 12 inches or closer for framing of 24 inches and 16 inches or closer for framing of 16 inches or closer.

The maximum RH requirement is 75-80%.

Elevator shaft walls are considered working walls. By that, they flex both inward and outward as the elevator passes by. This flexing causes the runner track to fail due to fatigue. Tests have shown that to oscillate one million cycles the gauge of the runner has to be increased to 24.

Yes, but they require fewer repair callbacks to fix edge-cracked corners.

OSHA’s Global Harmonization Standard (GHS) covers global hazardous material warnings on packaging. RCS is covered within the OSHA Hazard Communication Standard (2012), which is a job site regulation. The key difference between GHS and the new RCS regulation is that contractors are responsible for jobsite conditions, regardless of manufacturer packaging and/or SDS literature. 

USG has three products that can be used: Red Top® Gypsum Plaster, Red Top® Wood-Fiber Gypsum and USG® Structo-Base® Gypsum Plaster.

Yes. Because of its whiteness, the anhydrous form of calcium sulfate — such as that found in CA-5™ Calcium Sulfate Filler — is used successfully to extend Ti02 at a much lower cost.

No. The heights are slab-to-slab spans.

Wet-felted panels are typically mechanically perforated and fissured. They are very dense and more economical than other types of ceiling panels. Cast ceiling panels are non-perforated and are manufactured in a different “cast” process, hence its name, that enhances their surface appearance and provides excellent sound absorption and durability.

There are no ready-mixed joint compounds that exist that are 100% “silica free.”  However, the amount of respirable crystalline silica in USG joint compounds is low. 

The major difference between the two is density, Micore® 300 is 23±3 lbs./cu. ft. and Micore® 160 is 18±2 lbs./cu. foot.

No. The ceiling system achieves a time rating based on the entire assembly which includes roof deck or floor deck assembly.

Finish painting problems over new drywall are often caused by differences between the porosities and surface textures of gypsum panel face paper, and the finished joint compound. Decorating problems are magnified by the use of gloss paints. Then, when viewed in natural lighting, the joints and fasteners in decorated walls and ceilings may be visible.

All steel framing components for USG Cavity Shaft Wall are made to precise USG Specifications.

Depending on the market you are in, the product will be made at one of three manufacturing locations:

   • Marino/Ware Industries, South Plainfield, NJ
   • USG Medina, Medina, OH
   • CEMCO, City of Industry, CA

Yes, different joint compounds can be used over each other.

No, different joint compounds should never be mixed with each other.

UL Design Numbers U415, U438, U459, U467, U469, and U492.

A color darker than the desired result must be selected to compensate for the color change that occurs when the plaster is applied and dries.

The best way to cut a reveal edge in a panel is with a utility knife or a special Reveal edge tool.

Fiberock® Brand Abuse-Resistant Interior Panels can withstand temperatures of up to 125°F.

All of USG’s self-leveling underlayment products are crack-resistant but it is impossible to state that our products will never crack. Self-leveling underlayments are only as good as the substrate, its preparation, and the applicator.

When nailing to wood construction the spacing is 7 inches for ceilings, and 8 inches for walls. When screwing into wood and steel framing the spacing is 12 inches on ceilings and 16 inches for walls. Refer to the relevant fire test to determine fastener type and spacing.

RCS is a natural impurity in the raw materials used to manufacture USG ready-mixed joint compound, and varies by product, depending on product formulation and raw material source. If RCS is present, it will be indicated in Section 3 of the Safety Data Sheet (SDS), as required by OSHA. 

For heights exceeding the limiting height tables found in the System Catalog (SA926) brochure, we recommend installing the 20 gauge x 6" C-H Stud in combination with a standard 4" C-Stud of heavier gauge. The two stud sections should be fastened together (back-to-back with fasteners spaced 12" o.c. and staggered. The design or project structural engineer must review any design.

Yes, refer to Progressive Engineering Inc. Product Evaluation Report PER-01146.

Blistering joints are the result of not having enough joint compound under the tape. The best way to repair blistering joints is to open up the blistered area by slitting the tape. Fill the cut with joint compound and press tape back in place with knife blade.

Sheetrock® Brand Gypsum Liner Panels & Sheetrock® Brand Gypsum Panels (Firecode, Firecode C, or Ultracode Core. Please refer to the appropriate fire-resistance design for specific panel selection.

The paper is joint tape used in drywall finishing. Joint tape provides the best adhesion for paper to wallboard using joint compound.

Dihydrate calcium sulfate (CaS04•2H20), contains about 20% chemically combined water, othewise known as water of crystallization. Anhydrous calcium sulfate (CaS04), contains no water of crystallization.

Sheetrock® Brand Gypsum Panels can withstand temperatures up to 125°F.

Half-inch thick Fiberock® Brand Abuse-Resistant Interior Panels weigh 2.3 lbs per square foot and 5/8" thick panels weigh 2.9 lbs per square foot.

When installing a veneer plaster system it should be designed at deflection L/240 and L/360 for a Conventional Plaster system.

The maximum recommended control joint spacing for walls and ceilings without perimeter relief is 30 feet. With perimeter relief the maximum recommended control joint spacing is 50 feet.

There are designs that require Thermafiber insulation to achieve the fire rating. Check the UL Fire Resistance Directory for the specific design requirements. In other assemblies, the Thermafiber insulation is used to increase the STC. Fiberglass insulation cannot be substituted for Thermafiber insulation.

OSHA’s new silica rule is meant to protect workers from exposure to respirable crystalline silica (RCS) on jobsites. The Rule establishes a new 8-hour time-weighted average (TWA) Permissible Exposure Limit (PEL) of 50 µg/m³, an action level (AL) of 25 µg/m³ and a host of ancillary requirements. 

The elevator cab speed and the number of elevators per shaft determine the air pressure load. Yes, if not enclosed in an elevator shaft you can work off the 5 psf pressure load.

There are various products in the market which, when mixed with joint compounds, claim to improve various performance attributes of joint compounds.

USG does not endorse the use of additives in USG joint compounds for the following reasons:

An additive can adversely affect the unique balance of the many performance attributes each joint compound has been formulated to provide.

It is virtually impossible for an additive manufacturer to know if their additive is compatible at all times with all of USG's product formulations.

USG has no control over the manufacture and quality of additives manufactured by others.

Note - For taping and finishing joints, water can be added as necessary. USG recommends adding water in increments of a half-pint to avoid over thinning.

See USG Technical Information Sheet J1716 for more information.

Yes. Per ASTM D3273, "Standard Test Method for Resistance to Growth of Mold on the Surface of Interior Coatings in an Environmental Chamber," the following panels achieved a score of 10:

   • Sheetrock® Brand Glass-Mat Panels Mold Tough®
   • Sheetrock® Brand Gypsum Liner Panels
   • Sheetrock® Brand Mold Tough® Gypsum Liner Panels

Contractors should:

• Establish and implement a written exposure control plan for each jobsite (for assistance, visit http://plan.silica-safe.org)
• Identify and assign an individual with an understanding of RCS compliance obligations
• Communicate hazards and train employees

Yes, 30-minute single layer steel and wood framed, and one hour double layer steel framed fire-rated wall systems (UL Design U407).

When nailing to wood construction the spacing is 7 inches for ceilings, and 8 inches for walls. When screwing into wood and steel framing the spacing is 12 inches on ceilings and 16 inches for walls. Refer to the relevant fire test to determine fastener type and spacing.

There are two reasons to use 20-gauge framing for Fiberock® Brand Abuse-Resistant Interior Panel installation. The first is because Fiberock panels are used primarily in highly abused areas. If studs lighter than 20-gauge are used they will bow too much upon impact and cause joint cracking. Secondly, a great deal of force is required to penetrate the board.

It is best to use a minimum of .70 NRC and up to .80 - .90 NRC panel for this type of application.

USG Imperial® Veneer Finish Plaster is stronger and more abrasion resistant.

USG Diamond® Veneer Finish Plaster is designed for ease of use and slightly improved abrasion resistance when compared to gypsum panels.

Gypsum-based products can be used in almost every place that Portland cement-based products are used.

Gypsum products are generally less expensive, have superior compressive strengths (in most cases), and require less substrate preparation.

Portland cement is one of the largest contributors of CO₂ emissions. For each ton of Portland cement made, one ton of CO₂ emissions is produced. The Geopolymer binder of Durock™ EcoCap™ is made using a large quantity of industrial byproduct (fly ash) that is instrumental in keeping the CO₂ contribution of the product to very low levels. Compared to Portland cement, the net reduction in CO₂ emissions resulting from the Durock™ EcoCap™ binder is approximately 80%.

The washable, scrubbable and water repellent membrane is designed to be durable and safe with common disinfectants for general healthcare applications. Both acoustics and cleanability exceed FGI guidelines for healthcare.

Ultimately the floor covering adhesive manufacturer must approve use of their products over USG products. Please consult with adhesive manufacturer prior to use over USG products.

Respirable crystalline silica is a common mineral found in many naturally occurring and man-made materials.

Yes. We recommend that the splice not be located in the middle 1/3 of the span.

Please refer to System Catalog (SA926) for additional information.

The building codes require Firestop of all penetrations through fire-rated assemblies. Typically this includes floor/ceilings, elevator shafts, stairwells, corridors, etc. Of course, since the objective of Firestop systems is to contain fire to the area of origin, it is wise to seal all through-penetrations. Firestop also is needed at other joints, voids or gaps in fire-rated assemblies, at air passages and at plenums concealed within floor assemblies.

See USG Fire Stop Systems folder SA727 for tested systems and products.

When the slab extends over 2" from the interior side of the Shaft Wall that piece is there to offer protection from things falling onto the ledge and to provide safety to ensure nothing can sit or be left there. It does not have an effect on the fire rating.

• Product Evaluation: http://www.PER14076.com
• Assembly Evaluation: http://www.AER17108.com

A: Yes. We have 1, 2 and 3-hour UL rated wall assemblies.

• 1-hour (see item 6): www.ULV465.com
• 2-hour (see item 5): www.ULV465.com
• 3-hour: www.ULV471.com

Control joints are not to exceed 30 feet for walls and ceilings. The spacing for a ceiling with perimeter relief is not to exceed 50 feet.

The different panel substrates provide panels with unique characteristics. The use of the different panels will vary based on specific needs and application.

USG Ben Franklin™ products, USG Sof'n-Soil® and USG Calcium Sulfate Feed Grade are certified organic by the Organic Materials Registry Institute (OMRI) and many state organizations.

Celebration™, Panz™, and Libretto™ provide the best LR when unperforated. Panz™ and Celebration™ provide LR ±0.80 unperforated and in Flat White. Depending on the perforation pattern, LR rating will decrease.

Paraline®, due to its reveals would not provide as good a result.

Sheetrock® Brand Gypsum Lay-In panel is approved by both the USDA and the FSIS for use in commercial kitchens.

Yes. USG Sheetrock® Brand Dust Control Joint Compound (www.usg.com/dustcontrol) was specially formulated to reduce airborne dust. Under NIOSH and OSHA guidance, this technology is considered an engineering control. However, you are still responsible for maintaining jobsite conditions and compliance with the new silica rule. 

A: Bare floor = min. STC 54 with G556 or H505 on 10" o.c. C-Joist; attainable value over a range of floor covering:

The following acoustic ranges of STC/IIC values are available.

• Code minimum STC 50 / IIC 50 and higher
• Premium STC 55 / IIC 55 and higher
• Deluxe STC60 / IIC 60 and higher

Load data and spans are based on simple span tests in accordance with ASTM C635, with a deflection limitation of L/360.

The best grids to use in an area accessible to moisture are the Donn® AX™ Acoustical Suspension System or the Donn® ZXLA™ Acoustical Suspension System.

For residential installation 18-gauge wire is required. For commercial installation 12-gauge wire is required.

• ICC-ES Report: http://www.ESR1792.com

Place board inside, under cover and stacked flat on a clean floor in the centers of the largest rooms. All materials should remain in their packaging until ready for actual use. Place gypsum boards intended for use on ceilings on top of the pile since they will be used first. Do not stack long length boards on top of short length boards.

A: The side with the labeling is the top side for roof deck applications.

Clean sides and lid of container so no dried compound falls into the mixture. Level joint compound surface with a knife and cover container tightly. If storing, cover leveled surface of joint compound with approximately 1/2" of clean water and cover container tightly. Pour off water before reusing joint compound. Do not store in direct sunlight and protect from extreme heat and cold. The shelf life of an unopened container is up to nine months under proper storage conditions.

Correct, the only difference is that USG Hydrocal® 105 is yellow and USG Hydrocal® 106 is white.

For most interior applications, Durock® Brand Cement Board Panels are not affected by water and do not need to be waterproofed. Durock® is water durable but not waterproof. If you're looking for added protection to water sensitive material behind the Durock®, you may consider adding a waterproofing membrane. TCNA guidelines recommend the use of a waterproof membrane in interior wet areas. 

For exterior applications, consult your design professional as vapor permeance is climate dependent. 

Most moisture mitigation products will be compatible with USG Durock™ Brand Self-Leveling Underlayments. It is a good practice to check with the manufacturer of the moisture mitigation product before installing the self-leveling underlayment.

Select products based on the following:

Strength — USG offers products having compressive strengths ranging from 2,000 to 20,000 psi.

Flow Characteristics — USG formulates products to be extremely fluid, which is ideal for solid casting and capturing fine detail. USG also produces products with a lot of body for hollow castings and working characteristics needed by the end-user.

Expansion — Expansion can be helpful for certain applications, or if the need is for close tolerances, we offer products that will perform well. See Literature Numbers IG504 and IG278.

Set Time — The elapsed time from the moment the plaster and water come into contact until the time when the setting plaster has the ability to support an arbitrarily determined weight.

Working Time — Do not confuse setting time with working time. Working time refers to changes in the viscosity of the slurry along the way to the set time. Working time is always less time than setting time and varies by product. It is not a published number as customer perception of working time varies based on application.

There is a tip sheet for Securock® Gypsum-Fiber that can be found on the product page with a literature reference number RF-18.

Relax the serrated edge by pre-creasing or folding the strip. This ensures smooth removal of the masking and results in a clear tear that will not damage the trim.

The only USG Donn® Brand Fineline® Grid to use for this kind of system is the 1/4-inch USG Donn® Brand Fineline® DXF™/DXFL™ Acoustical Suspension System.

A: It is typical carpentry tools which you can find on Recommended Tools Sheet (SCP298287).

For a list of the fasteners recommended with STRUCTO-CRETE® Panels, reference our Recommended Fasteners Sheet (SCP297586).

Sheetrock® Brand Tuff-Hide™ Primer-Surfacer is a high solids vinyl acrylic latex based coating designed for the professional contractor for interior spray application over new drywall. In a single spray application it provides the same results achieved using a typical two-step process of skim coating surfaces with joint compound followed by a coat of primer.

No. On the contrary, USG Calcium Sulfate Feed Grade is used as a calcium enrichment for animal feed. USG Food and Pharmaceutical grade gypsum products are used in many human food and pharmaceutical applications. Gypsum should not be harmful if used appropriately.

Yes, USG Beta Dental Special is manufactured to a higher level of brightness (whiteness) standard than other beta plasters.

LR stands for light reflectance. It is a measure of the percentage of light which is reflected off of a given panel surface. Typically, the whiter and smoother the ceiling panel, the higher the LR value.

The MVER tolerances are 5 lbs./1,000 s.f./24 hours.

Weight is a major difference, but Sheetrock® Brand UltraLightweight All Purpose Joint Compound also has great workability, improved slip that makes it easy to wipe down and work with hand tools, very good wet tack that holds the tape in place securely so the finisher can run long strings of tape before coming back to wipe it in. The ultra light weight and wet tack also combine to keep the compound from dripping, thus reducing the time required to clean compound off the floors. Good open time is another benefit, enabling contractors to smooth a joint without the product drying prematurely and causing roll ups or tearing.

Flat ceilings constructed of gypsum board that are screw-attached to suspension members that support a ceiling on one level extending from wall to wall, are generally exempt from acoustical seismic construction requirements such as: perimeter end wall clearance, perimeter hanger wires, horizontal restraint and vertical splay bracing. This is due to the diaphragm strength achieved by screw-attached gypsum board. Gypsum board ceilings that do not extend perimeter to perimeter, or have multiple levels, may require seismic bracing depending on the local code interpretation.

USG Durock™ Brand Performance Flooring products are primarily meant to be used over properly prepared concrete. The products can also be used with metal lath over engineer-approved, APA-Rated exterior glue plywood or oriented strand board (OSB) (i.e., APA-Rated Exterior or Exposure 1 panels) wood subfloors following the Tile Council of North America's F-185-11 specification at a minimum ½ in. depth.

SDS files can be found on the product literature page.

For Durock™ Self-Leveling Underlayments, USG uses 50 lb. bags stacked 56 bags per pallet. We also can use high volume “super sacks” for larger jobs.

Durock™ Fast Finish Floor Patch is available in 10 lb. bags with 208 bags per pallet.

Sheetrock® Brand Plus 3™ Lightweight All-Purpose Joint Compound weighs about 25% less than Sheetrock® Brand All-Purpose Joint Compound. It is also easier to sand and shrinks less.

Yes, both W-60 and W-120 Oil Well Cements are available from Southard and Ft. Dodge in bulk.

Yes these products can be shipped with Fiberock and Durock. Durock® self-Leveling Underlayments and Fast Finish patch and skim coat are available nationwide.

The USG Fire Stop System with Firecode Compound and safing insulation works exceptionally well with metallic pipe, conduit and electrical cable. The systems also works in combination with intumescent wraps and collars to form an effective Firestop at through-penetrations for materials that can collapse, decompose or disintegrate in fire, such as Schedule 40 plumbing materials made of Acrylonitrile-Butadiene-Styrene (ABS), Polypropylene (PP) or Polyvinyl Chloride (PVC).

A: Review the installation guide — https://www.usg.com/content/dam/USG_Marketing_Communications/united_states/product_promotional_materials/finished_assets/usg-structural-panel-concrete-roof-deck-field-installation-guidelines-en-SCP43.pdf

These three formulas are controlled with specific accelerators and retarders at the manufacturing plant which will consistently achieve the advertised set time range for each product. Manipulating set time with water temperature and mixing is not as accurate and predictable.

No. USG Compässo™ Trim is pre-engineered in the factory for fast installation and repeatable quality.

Class A signifies that a panel attained a flame spread index of 25 or less (based on 100 for untreated red oak) when tested in accordance with the Standard ASTM E 84. The Firecode® brand signifies that the panel has been classified as a protective membrane in a floor-ceiling or roof-ceiling assembly in accordance with the Standard ASTM E 119. All Firecode® protective membranes offered by USG have attained a Class A rating.

The tensile strength requirement of the concrete is 175 psi.

USG has been manufacturing quality building material products for 110 years. We have been selling cement-based products for more than 30 years and have been making underlayment products since the 1970’s. We have an industry-leading R&D center in Libertyville, Illinois, and have several members of our technical staff who have PhD’s in cement-related fields.

Our Sheetrock® Brand Mold Tough® Abuse-Resistant VHI Firecode® Core Panels meet ASTM C1396 level 3 (highest) performance for soft and hard body impact resistance.

For ceiling with framing of 16 inches or closer, the spacing is 7 inches or closer for nails and 12 inches or closer for screws. Fastener spacing for walls are 12 inches or closer for framing of 24 inches and 16 inches or closer for framing of 16 inches or closer.

The maximum RH requirement is 75-80%.

USG offers 32 different curved main tees for a completely customized system.

Gypsum will provide calcium and sulfur to your soil and won't buffer the pH of your soil like limestone products. Gypsum can also help open air and moisture channels in the soil, improving soil struture and reducing run-off. Gypsum can also act to counter damage caused to plants by salt.

Yes. Some patterns are offered in both Class A and Firecode® branded formulations.

Firecode® Compound is packaged in 15 lb. bags. For small-volume applications, the compound can be portion mixed and the bag resealed.

2 1/2", 4" and 6" 25, 22 and 20 gauge. Please contact your local USG Representative for pricing and availability.

USG has three products that can be used: Red Top® Gypsum Plaster, Red Top® Wood-Fiber Gypsum and USG® Structo-Base® Gypsum Plaster.

No. The heights are slab-to-slab spans.

Wet-felted panels are typically mechanically perforated and fissured. They are very dense and more economical than other types of ceiling panels. Cast ceiling panels are non-perforated and are manufactured in a different “cast” process, hence its name, that enhances their surface appearance and provides excellent sound absorption and durability.

No, it doesn't matter. Regardless of which side faces out during installation, you can still expect the same great performance that professionals and do-it-yourselfers have come to expect from USG Durock® Brand Cement Board.

The purpose of the dual surfaces (one smooth side, one textured side) on USG Durock® Brand Cement Board is to better receive mastic and thin-set mortar. The smooth side is ideal for mastic applications, as it increases adhesive coverage. The textured side is ideal for mortar applications, as it enhances bonding and reduces tile slip. That said, mastic or thin-set mortar can be used on either side of the board without compromising performance.

The setting time of USG Hydrocal® X-21 Gypsum Cement provides low expansion, which benefits further formulation.

We recommend 150 grit paper or 220 grit mesh.

The majority of our filler products are manufactured from naturally occurring, high purity calcium sulfate at our plant in Southard, OK.

Sheetrock® Brand Durabond® Setting-Type Joint Compounds and Sheetrock® Brand Easy Sand™ Lightweight Setting-Type Joint Compounds are the best products to use for repairing cracks.

If you want to use a ready-mixed joint compound, Sheetrock® Brand All Purpose Joint Compound works well.

The major difference between the two is density, Micore® 300 is 23±3 lbs./cu. ft. and Micore® 160 is 18±2 lbs./cu. foot.

USG recommends that these products perform best when stored at temperatures below 110°F, protected from moisture or humidity and processed within one year of the date of manufacture. After this period of time, agglomerates may form which would affect the free flowing nature of the product. At recommended storage conditions, the one year recommendation relates primarily to processing, but combined moistures and reactivity could also be affected in extended storage.

UL Design Numbers U415, U438, U459, U467, U469, and U492.

USG offers four major types of acoustical panels as well as Gypsum based panels for special applications. They are: Wet-Felted, Cast, "X" Technology and Fiberglass.

Durock™ Self-Leveling Underlayment products are good for six months from the date of production.

Plaster can be stored 3-6 months if it is stored in a cool, dry place, protected from extreme heat and cold, direct sunlight and at a temperature above 45°F (7°C).

Remove the old plaster down to the wood lath, staple metal over the existing lath and apply Red Top® sanded conventional basecoat over the metal lath. Any USG finish plaster can be applied over the basecoat plaster for a final coat.

The best way to cut a reveal edge in a panel is with a utility knife or a special Reveal edge tool.

Fiberock® Brand Abuse-Resistant Interior Panels can withstand temperatures of up to 125°F.

Durock™ UltraCap™ — 23 square feet at ¼” for a 50 lb. bag

Durock™ Speed™ — 25 square feet at ¼” for a 50 lb. bag

Durock™ EcoCap™ — 20 square feet at ¼” for a 50 lb. bag

Durock™ Fast Finish — 41 square feet at 1/8” for a 10 lb. bag

Apply Fiberock® panels to subfloor using 1/4" x 1/4" square notch trowel with Type 1 organic adhesive or latex-modified thin-set mortar or dry-set mortar. Fasten to subfloor with 1-1/4" Durock™ brand tile backer screws for wood framing (or equivalent) or 1-1/2" hot-dipped galvanized roofing nails spaced 8" o.c. in both directions withperimeter fasteners at least 3/8" and less than 5/8" from ends and edges.

Yes, USG Prostone™ SM may be colored using appropriate pigments.

All of USG’s self-leveling underlayment products are crack-resistant but it is impossible to state that our products will never crack. Self-leveling underlayments are only as good as the substrate, its preparation, and the applicator.

When nailing to wood construction the spacing is 7 inches for ceilings, and 8 inches for walls. When screwing into wood and steel framing the spacing is 12 inches on ceilings and 16 inches for walls. Refer to the relevant fire test to determine fastener type and spacing.

No it is not approved for these types of application.

Do to the wide range of fabrics and glues on the market and how they may interact with one another we do not provide any specific recommendations.

For heights exceeding the limiting height tables found in the System Catalog (SA926) brochure, we recommend installing the 20 gauge x 6" C-H Stud in combination with a standard 4" C-Stud of heavier gauge. The two stud sections should be fastened together (back-to-back with fasteners spaced 12" o.c. and staggered. The design or project structural engineer must review any design.

Yes, refer to Progressive Engineering Inc. Product Evaluation Report PER-01146.

Sheetrock® Brand Gypsum Liner Panels & Sheetrock® Brand Gypsum Panels (Firecode, Firecode C, or Ultracode Core. Please refer to the appropriate fire-resistance design for specific panel selection.

Yes. USG Compässo™ Trim is available in 2 inches, 4 inches, 6 inches, 8 inches and 10 inches.

No, not at this time. Please contact your sales rep to discuss how to achieve a desired set time.

Sheetrock® Brand Gypsum Panels can withstand temperatures up to 125°F.

Half-inch thick Fiberock® Brand Abuse-Resistant Interior Panels weigh 2.3 lbs per square foot and 5/8" thick panels weigh 2.9 lbs per square foot.

When installing a veneer plaster system it should be designed at deflection L/240 and L/360 for a Conventional Plaster system.

Store Fiberock® indoors and protected from the elements. Protect them from extreme heat and cold and do not expose to direct sunlight.

Securock® Roof Boards are a portfolio of high performance roof boards to meet the needs of your low slope commercial roofing project. Each type of roof board is uniquely designed to help protect your roof when used as a fire barrier, thermal barrier, coverboard, recoverboard, or parapet wall.

Stocking distributors of Securock® Roof Boards can be found on the "Where To Buy" page.

The coverage rate is comparable to other USG ready-mix joint compounds. You can anticipate approximately two 4.5 gallon pails of Sheetrock® Brand UltraLightweight All Purpose Joint Compound to finish 1000 sq. ft. of gypsum wallboard.

Paper-faced beads provide superior adhesion to joint compound, primer and paint. They have a lower bead height than bare faced beads and trims. This requires less consumption of joint compound when coating the trims. They have an almost non-existent chance of leaching rust through the joint compound and finish paint. Tape-on trim rarely edge cracks, a common problem with nail-on and staple-on bead and trim.

Yes. Per ASTM D3273, "Standard Test Method for Resistance to Growth of Mold on the Surface of Interior Coatings in an Environmental Chamber," the following panels achieved a score of 10:

   • Sheetrock® Brand Glass-Mat Panels Mold Tough®
   • Sheetrock® Brand Gypsum Liner Panels
   • Sheetrock® Brand Mold Tough® Gypsum Liner Panels

Yes, USG Hydrocal® C-Base™ Gypsum Cement is higher in strength than USG Hydrocal® B-Base™ Gypsum Cement.

Yes, 30-minute single layer steel and wood framed, and one hour double layer steel framed fire-rated wall systems (UL Design U407).

When nailing to wood construction the spacing is 7 inches for ceilings, and 8 inches for walls. When screwing into wood and steel framing the spacing is 12 inches on ceilings and 16 inches for walls. Refer to the relevant fire test to determine fastener type and spacing.

It is best to use a minimum of .70 NRC and up to .80 - .90 NRC panel for this type of application.

USG food and pharmaceutical grade calcium sulfate filler products conform to FDA Regulation 21CFR184.1230, and are affirmed as GRAS (Generally Regarded as Safe). Calcium sulfate filler products are also safe to use in food packaging applications.

USG Imperial® Veneer Finish Plaster is stronger and more abrasion resistant.

USG Diamond® Veneer Finish Plaster is designed for ease of use and slightly improved abrasion resistance when compared to gypsum panels.

Sheetrock® Brand UltraLightweight All Purpose Joint Compound is an innovative product that has been developed to provide increased productivity and significantly less strain on workers. The increased productivity will more than offset the premium.

The washable, scrubbable and water repellent membrane is designed to be durable and safe with common disinfectants for general healthcare applications. Both acoustics and cleanability exceed FGI guidelines for healthcare.

Ultimately the floor covering adhesive manufacturer must approve use of their products over USG products. Please consult with adhesive manufacturer prior to use over USG products.

A: STRUCTO-CRETE® Panels can be supported by 18 ga. (43 mil.) or higher Cold-Formed Steel framing, SPF lumber, or Hot-Rolled Steel framing.

Typical span:

• Subfloor: 12", 16", 24"
• Roof Deck: 12", 16", 24", 32", 48"

• Product Evaluation: http://www.PER14076.com
• Assembly Evaluation: http://www.AER17108.com

"X" Technology is a unique manufacturing method which was developed by and introduced to the market by USG in 1989. This technology is used to produce ceiling panels with sag resistance and exceptional acoustical performance found in USG’s line of ceiling products with ClimaPlus™ Performance.

Sheetrock® Brand Tuff-Hide™ Primer-Surfacer provides installed cost savings versus traditional separate applications of a skim coat and prime coat. The product is ideal in critical light areas, or where a Level 5 or similar high quality finish is specified or desired. It is a high build durable coating that hides minor surface defects, minimizes callbacks caused by joint banding and photographing and provides a soother more beautiful paint finish than by simply using a drywall primer. In a ceiling application where a flat white finish is desired, Sheetrock® Brand Tuff-Hide™ Primer-Surfacer can be left unpainted providing an ideal final finish.

A: Yes. We have 1, 2 and 3-hour UL rated wall assemblies.

• 1-hour (see item 6): www.ULV465.com
• 2-hour (see item 5): www.ULV465.com
• 3-hour: www.ULV471.com

No product coloring is offered beyond the base color of USG Hydrocal® 105 Gypsum Cement.

USG manufactures two different types of Compässo™, standard Compässo™ made from steel, and Compässo™ Elite, which is made from extruded aluminum.

Compässo™ suspension trim clips are used to attach standard Compässo™ to main T’s and cross T’s, but these clips are not compatible with Compässo™ Elite.

USG Ben Franklin™ products, USG Sof'n-Soil® and USG Calcium Sulfate Feed Grade are certified organic by the Organic Materials Registry Institute (OMRI) and many state organizations.

Sheetrock® Brand Texolite™ Wall and Ceiling Texture Paint dries to a hard, durable natural white finish.

The maximum gap should not exceed 1/8 of an inch.

The shelf life of an unopened container is up to nine months from the date of manufacture under protected storage conditions.

Yes. In addition to the 5-gallon pail, Sheetrock® Brand Tuff-Hide™ Primer-Surfacer is available in 50-gallon drums.

Levelrock® is a gypsum-based self-leveling underlayment sold to a network of certified applicators. If you are interested in becoming a Levelrock® applicator, please contact your sales rep.

Design Solutions are a pre-engineered product to help expedite availability. All products are made to order and shipped within 8 weeks from order confirmation (up to 2,500 sq ft).  For orders more than 2,500 sq ft. a representative will contact you to verify availability.

Design Solutions are a pre-engineered product to help expedite availability. All products are made to order and shipped within 8 weeks from order confirmation (up to 2,500 sq ft).  For orders more than 2,500 sq ft. a representative will contact you to verify availability.

A: Bare floor = min. STC 54 with G556 or H505 on 10" o.c. C-Joist; attainable value over a range of floor covering:

The following acoustic ranges of STC/IIC values are available.

• Code minimum STC 50 / IIC 50 and higher
• Premium STC 55 / IIC 55 and higher
• Deluxe STC60 / IIC 60 and higher

A: USG recommends min. 1/4" USG Fiberock® Brand Underlayment board or 3/4" depth pour of USG Levelrock® Brand 2500.

The best grids to use in an area accessible to moisture are the Donn® AX™ Acoustical Suspension System or the Donn® ZXLA™ Acoustical Suspension System.

USG Donn® Brand CE™ Acoustical Suspension System is the best grid for a Clean Room environment.

A: STRUCTO-CRETE® Panels are:

• 3/4" thick
• 4' x 8'; 4' x 6'; 4' x 6'-8" panels^A
• Pallet: 20 panels^B
• Edge: T&G^C
  
  

1. Panels can be custom cut
2. Can be requested to have 10 panels per pallet.
3. Can also be Square Edge if requested.

A: No. STRUCTO-CRETE® Panels are the only UL-certified noncombustible cementitious panel in North America. STRUCTO-CRETE® Panels offer the simplest 2-hour floor/ceiling fire assembly which saves time and money.

A: STRUCTO-CRETE® Panels are compliant with the 2012, 2015 and 2018 IBC.

A: STRUCTO-CRETE® Panels are cured-in-factory 3/4" panels that are high-strength, fiberglass reinforced concrete panels for use in noncombustible Types I and II construction. The panels are certified noncombustible by Underwriters Laboratories Inc (UL) in accordance with the current version of ASTM E136. The panels take the place of traditional poured concrete and metal deck in cold-formed steel framing, STRUCTO-CRETE® Panels are a lighter and easier solution, requiring only the basic carpentry tools for installation.

A. Yes. We have the simplest 2-hour assemblies G556 and H505 with one layer of drywall (ULIX). We have the most comprehensive testing database of any panel for different assemblies, which can be found at: www.USGStructuralUL.com

A: No, must be covered and protected from traffic wear.

A: The carpenter typically leads the installation of STRUCTO-CRETE® Panels, which allows you to eliminate the many trades needed to pour concrete.

A: STRUCTO-CRETE® Brand Structural Panels are for subfloor applications, typically used in midrise buildings, health facilities, theaters, hotels, residential buildings and homes, multipurpose midrise buildings, panelized construction or in simple platforms or mezzanines. It is also used as the lightweight floor in permanent modular construction.

STRUCTO-CRETE® Brand Structural Roof Deck Panels are for roof deck applications, typically used for commercial low-slope or residential sloped roofing, balconies, and canopies. To see more information on what can be applied to STRUCTO-CRETE® Roof Deck Panels, reference High Performance Roof Applications (SCP68).

A: Review the installation guide.

A: View USGStructuralVideos.com for Project Profiles on just a few of the projects that have used STRUCTO-CRETE® Panels.

• ICC-ES Report: http://www.ESR1792.com

A: Refer to our repair manual that takes you through the steps of repairing damages of square holes max. 6" by 6" or round holes max. 6" in diameter.

STRUCTO-CRETE® Panels are:

• Lighter – less weight, less overall structural material
• Faster – no wait for curing, fewer trades (carpenters can install STRUCTO-CRETE® Panels), greater schedule flexibility, faster time to open
• Lower risk – no moisture uncertainty, cured so there is no excessive free water
• Lower total installed cost – fewer trades, less material, less equipment, faster time to open

A: STRUCTO-CRETE® Panels are easy to install (lay, fasten, finish), and only requires a single trade. Unlike poured concrete, it can be installed in any weather, and it eliminates the wait to cure and dry. Other trades (e.g. mechanical and electrical) can begin work sooner. Schedule compression leads to lower project cost and faster time to open.

A: A variety of floor coverings can be used but an engineered underlayment is recommended over the panel except with carpet and pad.

A: The side with the glass-mat is the top side for floor applications.

The wall should be installed from floor to floor.

USG always recommends shot blasting, sand blasting, or scarifying a floor prior to installations of our self-leveling products. To decide whether mechanical preparation of substrate is required or not, the concrete substrate must be thoroughly assessed for its quality and tensile strength over the entire pour area. The assessment of concrete tensile strength must be made in its existing state without the removal of any foreign material that may be present on the concrete surface. Simple visual appearance of concrete substrate as strong and solid does not necessarily guarantee that the concrete substrate is free of impurities and has the right tensile strength.

A weak or degraded concrete surface layer must be removed mechanically to provide a solid base. Concrete exhibiting signs of laitance (a layer of weak material on the concrete surface either visible or invisible), scaling, spalling, crumbling or delamination must be mechanically removed to achieve a solid and clean substrate. Prior to installation of the underlayment, mechanically profile concrete subfloor to a minimum of CSP 3, in accordance with the industry standards as outlined in International Concrete Repair Institute (ICRI) Technical Guideline No. 310.2 Selecting and Specifying Concrete Surface Preparation for Sealers, Coatings, and Polymer Overlays.

Use mechanical removal methods such as shot blasting, scarifying or diamond grinding to clean and prepare the concrete subfloor contaminated with adhesives, asphalt or oil. Shot-blasting is the preferred method of mechanically profiling and preparing the concrete subfloor for the application of USG self-leveling underlayments.

No. When using fiberglass tape, only setting-type joint compounds like Sheetrock® Brand Durabond® and Sheetrock® Brand Easy Sand™ should be used for the first coat over the tape. Ready-mixed drying-type compounds can be used for subsequent finishing coats.

A: The side with the labeling is the top side for roof deck applications.

Clean sides and lid of container so no dried compound falls into the mixture. Level joint compound surface with a knife and cover container tightly. If storing, cover leveled surface of joint compound with approximately 1/2" of clean water and cover container tightly. Pour off water before reusing joint compound. Do not store in direct sunlight and protect from extreme heat and cold. The shelf life of an unopened container is up to nine months under proper storage conditions.

Only one single-spray application is necessary to achieve a smooth surface.

No, the painting of Micore will impair acoustical and fire performance and will void all manufacturer warranties.

Do not exceed 16 inches on center.

Always refer to a roof design professional and/or FM for the amount of fasteners. We have a fastener pattern sheet that can help you with the placement of fasteners.

Nail-on bead and trim is attached to framing (usually wood). They twist and edge crack when the framing moves due to lumber drying and settling. Tape-on bead and trip floats with the wallboard when the framing moves and the building settles. They do not edge crack when these situations occur.

Yes, running a mechanical taping tool is now easier than ever due to the 40% weight reduction and easy flow of Sheetrock® Brand UltraLightweight All Purpose Joint Compound. Finishers will appreciate the significant difference when using Sheetrock® Brand UltraLightweight All Purpose Joint Compound in a mechanical taping tool.

The main T’s and cross T’s are punched to easily frame for nominal 2’x2’ and 2’x4’ type G and F light fixtures. USG manufactures 15/16” faced cross T’s to accommodate type G fixtures, and 50” and 26” cross T’s to frame openings for type F fixtures.

Complete light fixture installation details can be found in USG publication AC3152, USG Drywall Suspension Systems Catalogue.

For most interior applications, Durock® Brand Cement Board Panels are not affected by water and do not need to be waterproofed. Durock® is water durable but not waterproof. If you're looking for added protection to water sensitive material behind the Durock®, you may consider adding a waterproofing membrane. TCNA guidelines recommend the use of a waterproof membrane in interior wet areas. 

For exterior applications, consult your design professional as vapor permeance is climate dependent. 

The maximum space allowed between panels is 1/8 of an inch. Any space larger can lead to problems with joint finishing cracking.

Most moisture mitigation products will be compatible with USG Durock™ Brand Self-Leveling Underlayments. It is a good practice to check with the manufacturer of the moisture mitigation product before installing the self-leveling underlayment.

Yes. The joints must be taped with paper tape and setting type compounds. Apply a two coat veneer plaster.

In interior basement finishing applications over wood or metal framing yes; however, not direct ground contact applications.

Relax the serrated edge by pre-creasing or folding the strip. This ensures smooth removal of the masking and results in a clear tear that will not damage the trim.

Yes. For all pumping applications contact USG Technical Services. Pumping these products must be done by an experienced contractor with approved equipment

No, Securock® Roof Boards will cut with ordinary utility knifes using a score an snap method. For thicker boards like Securock 1/2" Gypsum-Fiber, two scores will be necessary. For 5/8" Securock Gypsum-Fiber a tool such as a circular saw will be necessary. It is highly recommended that a wet or dry vacuum be attached to the circular saw to reduce the dust and that the person cutting Securock Roof Boards and those in the vicinity of the cut wear a NIOSH approved dust mask.

Yes. USG has more than 60 UL designs where Drywall Suspension Systems are listed. In fact, the system can be used in place of cold rolled channel and furring channel in any UL fire rated design.

Firecode® Brand Acrylic Firestop Spray Sealant is spray applied and used to provide a low installed cost solution in firestopping dynamic joints in head of wall designs.

No. Sheetrock® Brand Setting-Type Joint Compounds (Durabond® and Easy Sand™) are recommended to treat joints in exterior gypsum ceiling board.

A: It is typical carpentry tools which you can find on Recommended Tools Sheet (SCP298287).

For a list of the fasteners recommended with STRUCTO-CRETE® Panels, reference our Recommended Fasteners Sheet (SCP297586).

Sheetrock® Brand Tuff-Hide™ Primer-Surfacer is a high solids material which is spray-applied much thicker (15-20 mils wet is recommended) than a typical primer or paint to provide a smooth surface.

USG Durock™ Brand EcoCap™ and USG Durock™ Brand Speed™ can be walked on after two hours, non-moisture sensitive products can be installed in as little as four hours, and most other floor coverings in 16 hours.

USG Durock™ Brand UltraCap™ can be walked on in two hours, with light trade traffic in 24 hours and floor covering application in as little as 48 hours.

Additionally always follow the floor covering manufacturer’s recommendations.

Yes. Each coat must be completely dry before applying the next.

Durock™ UltraCap™ — 2-3 days, depending on climate and environment

Durock™ Speed™ — Non-moisture sensitive tile in 4 hours, other floor coverings in 16 hours

Durock™ EcoCap™ — Non-moisture sensitive tile in 4 hours, other floor coverings in 16 hours

Durock™ Fast Finish — Depending on thickness, floor covering can be put down in as little as 15 minutes after set

Yes. Fiberock® Brand Abuse-Resistant Interior Panels can be curved to radius of 30' for 1/2" thickness and 50' for 5/8" thickness.

The CMU must cure for at least 45 to 60 days prior to the plaster application. Refer to USG system folder SA920 for specific application directions.

We have a great Securock® Roofing Team that can help you out with your project wherever it is. Please email securockroofing@usg.com and someone will assist you.

Use Durock™ Primer-Sealer, a low VOC, high-solids acrylic primer, for sealing the concrete and wood subfloor prior to application of Durock™ self-leveling underlayment. Proper use of Durock™ Primer-Sealer effectively seals the subfloor and prevents formation of pinholes, domes and craters in self-leveling underlayment due to upward migration of the air bubbles from the subfloor. Floors to be primed must be dry, structurally sound and clean. Remove any dirt, tar, wax, oil, grease, latex compounds, sealers, curing compounds, release agents, asphalt, adhesives, paint, chemicals, loose topping, joint compounds from drywall installation or any other contaminant that might interfere with development of good bond.

Apply Durock™ Primer-Sealer in a two-step application. For the first application, dilute 1 part of Durock™ Primer-Sealer to 4 parts of water. Mix the diluted solution with a paddle mixer at slow speed for approximately 1 minute. Next, apply primer solution to the subfloor at a coverage rate of approximately 200-300 sq. ft./gal. using a soft push broom. Apply evenly and do not puddle. The actual coverage of the primer will depend upon the nature and porosity of the subfloor. High absorption concrete will require more primer. Allow the first coat to dry for a minimum of 1 hour prior to the application of the second coat.

For the second application, dilute 1 part Durock™ Primer-Sealer to 1 part of water. Mix gently with a paddle mixer at slow speed for approximately 1 minute. Next, apply the primer solution to the subfloor using a soft push broom. Apply the primer evenly and do not puddle. The coverage rate of the diluted primer is approximately 300 sq. ft./gal. Again, the actual coverage of the primer will depend upon the nature and porosity of the subfloor. Allow the second coat to dry to a clear thin film for a minimum of 3 hours and a maximum of 16 hours before recoating will be necessary. High air relative humidity and/or low subfloor temperature may necessitate a longer drying time. Primer must be completely dry before application of the self-leveling underlayment. Extremely porous concrete subfloors may require an additional application.

For primer application, the temperature of Durock™ Primer-Sealer, the subfloor and the room must be maintained between 50°F and 95°F for a period of 72 hours before and after application.

Flat ceilings constructed of gypsum board that are screw-attached to suspension members that support a ceiling on one level extending from wall to wall, are generally exempt from acoustical seismic construction requirements such as: perimeter end wall clearance, perimeter hanger wires, horizontal restraint and vertical splay bracing. This is due to the diaphragm strength achieved by screw-attached gypsum board. Gypsum board ceilings that do not extend perimeter to perimeter, or have multiple levels, may require seismic bracing depending on the local code interpretation.

Yes, mobile mixers, when calibrated properly, can be used to mix USG Duracal® Cement.

USG Durock™ Brand Performance Flooring products are primarily meant to be used over properly prepared concrete. The products can also be used with metal lath over engineer-approved, APA-Rated exterior glue plywood or oriented strand board (OSB) (i.e., APA-Rated Exterior or Exposure 1 panels) wood subfloors following the Tile Council of North America's F-185-11 specification at a minimum ½ in. depth.

Leave a 1/4" space between the bottom edge of the corner bead or trim and the floor.

This is not something we recommend. Instead, wesuggest using USG Durock® Brand Cement Board for this type of situation.

Micore Mineral Fiber Boards are used as a component in various types of systems and you should consult the system manufacturer for details.

Sheetrock® Brand Plaster of Paris sets in approximately 30 minutes.

Yes. It is possible to substitute studs as long as the stud is of thicker gauge, size, or both.

Over time stains settle into a wall or ceiling. When that area is retextured the stains photograph through causing a yellowing or browning effect. The best way to prevent staining is to apply a stain blocker, primer, and sealer.

Yes, but it is recommended that they set for a few hours before filling.

No. It is recommended that a plaster bonder be applied first, then Sheetrock® Brand Tuff-Hide™.

No. Sheetrock® Brand Tuff-Hide™ Primer is formulated for interior application over new drywall.

Sheetrock® Brand Plus 3™ Lightweight All-Purpose Joint Compound weighs about 25% less than Sheetrock® Brand All-Purpose Joint Compound. It is also easier to sand and shrinks less.

Fasteners should be located at both ends, and staggered 12 inches or closer the full length of the studs.

No.

A: Review the installation guide — https://www.usg.com/content/dam/USG_Marketing_Communications/united_states/product_promotional_materials/finished_assets/usg-structural-panel-concrete-roof-deck-field-installation-guidelines-en-SCP43.pdf

Gypsum panels can be installed horizontally or vertically. Installing the board horizontally lessens the total amounts of joints to be taped by 25%.

No. USG Compässo™ Trim is pre-engineered in the factory for fast installation and repeatable quality.

No, Fiberock® Brand Abuse-Resistant panels are not approved for exterior use.

The tensile strength requirement of the concrete is 175 psi.

Veneer plaster can be painted when it is completely dry. The best way to determine if the plaster is dry is by taping a piece of 12" by 12" plastic to the surface. If any moisture remains on the plastic after 24 hours then the plaster is not completely dry.

Hot-dipped galvanized roofing nails, ring shanked, or Durock™ Brand Wood Screws.

Mix Color Trend and water together in a bucket using a heavy-duty 450-RPM drill with a drywall blade-type joint compound paddle. Turn the drill on and off several times to evenly disperse the colorant through the water and to prevent splashing.

Yes. Any loss of the colorant causes color variation in the finished material.

Yes, Sheetrock® Brand UltraLightweight All Purpose Joint Compound can be used for taping with paper tape, applying Sheetrock® Brand paper faced bead, covering fasteners, and throughout the entire finishing process.

Yes. The USG Drywall Suspension System is designed to be compatible with most USG Donn® Brand Suspension Systems, making it easy to transition from gypsum board ceilings to acoustical tile ceilings.

It is critical to have high air exchange with dry make up air for effective drying. We provide some good technical information in USG publication IG502, Drying Plaster Casts.

For ceiling with framing of 16 inches or closer, the spacing is 7 inches or closer for nails and 12 inches or closer for screws. Fastener spacing for walls are 12 inches or closer for framing of 24 inches and 16 inches or closer for framing of 16 inches or closer.

The maximum RH requirement is 75-80%.

No.

Yes. Insulation can be added without any decline in fire resistance. Also, if that same assembly requires insulation it must be added.

Sheetrock® Brand First Coat Primer is a flat latex wall primer that equalizes surface texture and porosity differences between the drywall face-paper and areas finished with joint compound to minimize drywall decorating problems.

Under conditions of a temperature of 70° and 70% humidity, joint compound should dry in about 24 hours. Higher humidity and/or lower temperatures will slow drying time.

Yes, but they require fewer repair callbacks to fix edge-cracked corners.

Due to its high abrasion resistance Tuff-Hide is not very sandable. Areas in need of touch-up, such as nicks, voids, protrusions, paper tears, etc. must first be filled and leveled with joint compound, then sanded smooth. Using a feathering spray technique Tuff-Hide should be blended into the surrounding coated surface.

For larger repaired areas, it may be necessary to re-spray the entire wall or ceiling surface. When re-spraying is not feasible, Sheetrock® Brand First Coat can be used over repaired areas using a high quality roller with a 1/8" to 1/4" nap and blended into the surrounding surface using a feathering technique.

USG has three products that can be used: Red Top® Gypsum Plaster, Red Top® Wood-Fiber Gypsum and USG® Structo-Base® Gypsum Plaster.

No. Firecode Compound should not be applied to moist areas or areas continuously exposed to moisture.

No. The ceiling is designed to carry only its own weight.

No. Tape-on bead and trim can be applied using drywall finishing tools and nail-on bead and trim can be applied using drywall applicator tools.

Yes, Sheetrock® Brand UltraLight Panels Firecode® X complies with ASTM C1396 requirements for 5/8" type X wallboard panels.

You will need a bucket, scale and mixing equipment. Mixing could be accomplished through basic hand mixing with a large spoon, but mechanical mixing is preferred. An electric drill with a cage mixer head attached is good for small batches.

The first step involves measuring and adding enough water to the bucket to achieve the desired consistency. You then need to weigh out enough gypsum plaster to meet the proper ratio for the selected water volume. Sift the plaster into the bucket of water and allow the plaster to soak for 1 to 2 minutes. Follow this immediately with mixing, generally for 1 to 2 minutes based on product.

NOTE: If mixing by hand, use vigorous stirring action. After mixing and pouring the gypsum slurry, make sure to clean all tools and the mixing vessel before the plaster hardens.

For more detail on mixing, see USG publication IG503, Plaster Mixing Procedures.

The joints should be embedded with setting type compound and paper tape.

Yes, but only on open throat doorframes, per door manufactures requirements. Red Top® Gypsum Plaster mixed with sand is most commonly used for full grouts. (Recommendation: 1-part Red Top Gypsum/ 2-parts sand per bag) 

See the Gypsum Construction Handbook for full details.

Yes. Fiberock® Brand Aqua-Tough™ Underlayment and Tile Backerboard are both recommended in areas where protection against mold and moisture is needed. These products are ideal for residential shower applications were versatility is needed, these panels can be tiled and painted for added installation convience.

No, it doesn't matter. Regardless of which side faces out during installation, you can still expect the same great performance that professionals and do-it-yourselfers have come to expect from USG Durock® Brand Cement Board.

The purpose of the dual surfaces (one smooth side, one textured side) on USG Durock® Brand Cement Board is to better receive mastic and thin-set mortar. The smooth side is ideal for mastic applications, as it increases adhesive coverage. The textured side is ideal for mortar applications, as it enhances bonding and reduces tile slip. That said, mastic or thin-set mortar can be used on either side of the board without compromising performance.

We recommend 150 grit paper or 220 grit mesh.

Yes. Water does not affect the USG Durock® Brand panels themselves; however, because water could affect other materials, TCNA Handbook Guidelines recommend the use of a waterproof membrane in wet areas.

No. The panel must be used in areas that are dry before, during, and after installation. For areas where mold, moisture and abuse resistance is needed use Fiberock® Brand Aqua-Tough™ Interior Panels.

Sheetrock® Brand Durabond® Setting-Type Joint Compounds and Sheetrock® Brand Easy Sand™ Lightweight Setting-Type Joint Compounds are the best products to use for repairing cracks.

If you want to use a ready-mixed joint compound, Sheetrock® Brand All Purpose Joint Compound works well.

The difference is in one case the load is considered intermittent, or the load is only applied as the elevator moves by. In the other case the load is sustained or constant. This would be the case for air handling systems. The sustained load is far more severe. The codes allow us to increase the allowable stress by 1/3 if the load is considered intermittent.

No. The ceiling system achieves a time rating based on the entire assembly which includes roof deck or floor deck assembly.

A conventional plaster system can be painted after it is completely dry.

Finish painting problems over new drywall are often caused by differences between the porosities and surface textures of gypsum panel face paper, and the finished joint compound. Decorating problems are magnified by the use of gloss paints. Then, when viewed in natural lighting, the joints and fasteners in decorated walls and ceilings may be visible.

Yes, different joint compounds can be used over each other.

No, different joint compounds should never be mixed with each other.

No, the patented nose coating on paper-faced bead and trim prevents the paper from fuzzing or when sanded.

Only professional spray equipment with a minimum output of 1 gallon per minute, pump pressure rated at 2700-3000 psi, that accommodates a 0.031 spray tip at 2000 psi is recommended. The Graco Mark V is one example of approved airless pumping equipment.

Spray equipment that does not meet these minimum requirements may apply the product in a non-uniform manner and provide an unacceptable appearance. Professional spray equipment that meets these minimum specifications typically cost $4000 and higher, but will experience less wear, have a longer working life and provide excellent results.

Yes. Although the components cannot be bent at the jobsite, USG offers complete factory curved components for curved ceilings, domes, and vaults. Ceiling designs can be submitted, and all of the parts and pieces for the installation will be manufactured and shipped out as a kit for faster and easier installation.

For more information, please call the USG Customer Service Center at 1.800.950.3839.

Yes. A single application of Sheetrock® Brand Tuff-Hide™ at 15-20 mils wet film thickness can be used in lieu of the skim coat and prime coat steps in a Level 5 finish. It is critical however that a Level 4 finish is completed prior to the application of the Sheetrock® Brand Tuff-Hide™. While the Sheetrock® Brand Tuff-Hide™ product will fill and hide many minor surface imperfections, it is not intended to achieve a Level 5 finish from a surface prepared to a Level 3 or below. It is also critical that the product be applied to a minimum 15 mils WFT in order to achieve the desired results. A Wet Film Thickness gauge should be used throughout the application process to ensure proper thickness.

The recommendation for hold-down clip spacing is two clips per panel, centered on the grid, between the panels.

Yes, Sheetrock® Brand UltraLight Panels are manufactured to meet ASTM C1396 Specifications for 1/2" gypsum wallboard and 1/2" gypsum ceiling board, and comply with the requirements of the International Building Code and International Residential Code as both regular wallboard and ceiling board.

Remove the old plaster down to the wood lath, staple metal over the existing lath and apply Red Top® sanded conventional basecoat over the metal lath. Any USG finish plaster can be applied over the basecoat plaster for a final coat.

In order to achieve span heights greater than the limited spans the system must be tied back to the structure. The Architect or Engineer of Record determines the details for this attachment.

Yes. Sheetrock® Brand Texolite™ conceals minor surface defects.

Not in general. The exception is the Sheetrock® Brand Shaft Wall, which is the only wall assembly that can be tested for ceilings by testing it horizontally.

A color darker than the desired result must be selected to compensate for the color change that occurs when the plaster is applied and dries.

They can be cut with a utility knife, or a low RPM 3 1/2" carbide blade saw with a dust collection device.

The best way to cut a reveal edge in a panel is with a utility knife or a special Reveal edge tool.

Durock™ UltraCap™ — 23 square feet at ¼” for a 50 lb. bag

Durock™ Speed™ — 25 square feet at ¼” for a 50 lb. bag

Durock™ EcoCap™ — 20 square feet at ¼” for a 50 lb. bag

Durock™ Fast Finish — 41 square feet at 1/8” for a 10 lb. bag

Consult paint manufacture for proper primer selection for both lime-containing finish plasters, such as Diamond® Veneer Finish; or non-lime-containing finish plasters such as Imperial® Veneer Finish. See literature piece PM15 for Preparation for Painting details.

Apply Fiberock® panels to subfloor using 1/4" x 1/4" square notch trowel with Type 1 organic adhesive or latex-modified thin-set mortar or dry-set mortar. Fasten to subfloor with 1-1/4" Durock™ brand tile backer screws for wood framing (or equivalent) or 1-1/2" hot-dipped galvanized roofing nails spaced 8" o.c. in both directions withperimeter fasteners at least 3/8" and less than 5/8" from ends and edges.

Yes. By following these instructions.

1. Remove all loose debris from the cut-back.

2. Spread dry Fast Finish over the cutback adhesive and then work the dry powder into the floor with a broom. Then take a razorblade scraper and scrape the cut-back down to a very thin thickness and allow any residual moisture from solubility test or clean up to thoroughly dry prior to the application of Fast Finish.

3. Skim-coat the area with Fast Finish.

Higher temperatures will typically cause faster set times and less flow time while cooler temperatures will have the opposite effect. USG recommends that material, concrete subfloor and room temperature must be between 50°F and 95°F at the time of application and for 72 hours after installation. For temperatures above 95°F, follow the American Concrete Institute (ACI) Hot Weather Concrete guidelines to ensure proper installation.

When nailing to wood construction the spacing is 7 inches for ceilings, and 8 inches for walls. When screwing into wood and steel framing the spacing is 12 inches on ceilings and 16 inches for walls. Refer to the relevant fire test to determine fastener type and spacing.

USG Celebration™ Panels can be snapped over an existing Fineline ceiling as a retrofit upgrade. It can also have acoustical tile above to for enhanced NRC performance.

Durock™ UltraCap™ – 4.5 – 5.0 quarts (1.0 – 1.25 gallons)

Durock™ Speed™ – 5.0 – 5.5 quarts (1.2 – 1.45 gallons)

Durock™ EcoCap™ – 3.2 – 3.4 quarts (0.8 – 0.85 gallons)

For heights exceeding the limiting height tables found in the System Catalog (SA926) brochure, we recommend installing the 20 gauge x 6" C-H Stud in combination with a standard 4" C-Stud of heavier gauge. The two stud sections should be fastened together (back-to-back with fasteners spaced 12" o.c. and staggered. The design or project structural engineer must review any design.

The system does not lend itself for tight radii. A 50 radius has been done, but anything less would require the assistance of the USG Architectural Services group. They can be contacted at 1-800-USG-4YOU (800-874-4968).  

Yes. Type C can be used in place of Type X, but Type X cannot be used in place of Type C.

Blistering joints are the result of not having enough joint compound under the tape. The best way to repair blistering joints is to open up the blistered area by slitting the tape. Fill the cut with joint compound and press tape back in place with knife blade.

Yes. For uniform coloring, colorants can be added to the mix water and should be blended thoroughly. For varied color effects, colorants can be added to the slurry.

Both mineral colorants and water dispersed colorants are compatible with our plaster products.

Tuff-Hide can be tinted to provide better hide of the finish paint. A tint plug is included on the lid of the 5-gallon pail.

Mix for 60-90 seconds. Scrape sides and mix for another 15-30 seconds. Do not re-temper.

No. An alum spray must be applied prior to application.

Yes. It is important to note that insulation cannot be arbitrarily added to a fired rated floor ceiling assembly that was tested without insulation. The use and location of insulation in the assembly can dramatically affect fire performance because insulation traps heat (even if it is being used for sound purposes) and can cause premature failure.

USG has UL-tested assemblies where insulation is installed directly on the back side and supported by the gypsum board. Other drywall grid systems do not have this feature so careful selection is important.

Fiberock® Brand Abuse-Resistant Interior Panels can be primed and painted the same as regular drywall. For more information, see USG literature piece J2045, Fiberock® Panels Finishing & Decorating White Paper.

When installing a veneer plaster system it should be designed at deflection L/240 and L/360 for a Conventional Plaster system.

The coverage rate is comparable to other USG ready-mix joint compounds. You can anticipate approximately two 4.5 gallon pails of Sheetrock® Brand UltraLightweight All Purpose Joint Compound to finish 1000 sq. ft. of gypsum wallboard.

We recommend using USG Durock™ Brand Tile Backer Screws. Hot-dipped galvanized roofing nails, ring shanked, are also acceptable.

The maximum recommended control joint spacing for walls and ceilings without perimeter relief is 30 feet. With perimeter relief the maximum recommended control joint spacing is 50 feet.

Yes

Yes. Sheetrock® Brand Durabond® Sheetrock® Brand Easy Sand™, Sheetrock® Brand All Purpose, and Sheetrock® Brand Joint Taping Compounds provide the best performance bonding gypsum panels.

Due to the high solids and heavy viscosity of the product, airless spray application is the only method recommended. Back-rolling with a nap roller is not recommended.

Most paints are acceptable finishes for plaster. It is critical to make sure the plaster cast is dry before applying a finish. If painting requires areas of color detail, the recommendation is that a base coat be applied before the details are painted.

Do not locate the splice in the middle 1/3 of the span.

Firecode® Brand Intumescent Acrylic Firestop Sealant Type IA is usually applied with a caulk gun. Type IA materials greatly expand when exposed to high temperatures. Type IA is used when the integrity of penetrants is compromised by high temperature, such as in PVC (plastic) pipe or some insulated pipes.

Refer to USG Firestop Systems folder, SA727, for information on the systems offered for fire protection of through-penetrations and head-of-wall construction joints using these products.

No. The joints do not require tape, however it is necessary to stagger the joints of the liner panels. Please refer to System Folder System Catalog (SA926) for detailed information on this application.

There are various products in the market which, when mixed with joint compounds, claim to improve various performance attributes of joint compounds.

USG does not endorse the use of additives in USG joint compounds for the following reasons:

An additive can adversely affect the unique balance of the many performance attributes each joint compound has been formulated to provide.

It is virtually impossible for an additive manufacturer to know if their additive is compatible at all times with all of USG's product formulations.

USG has no control over the manufacture and quality of additives manufactured by others.

Note - For taping and finishing joints, water can be added as necessary. USG recommends adding water in increments of a half-pint to avoid over thinning.

See USG Technical Information Sheet J1716 for more information.

One reason may be the addition of too much water to texturing material or paint. Over-thinned paint or texture material does not adequately hide the normal contrast between the joint and gypsum panel paper. It is recommended before texturing and painting, that a prime coat of Sheetrock® Brand First Coat or undiluted, interior flat latex paint with high solids content is applied to the wall or ceiling surface.

Any corrosion resistance nail or screw of the type and length for the framing members used. Consult the project design professional for these requirements.

No. This product should never be used in areas that are exposed to continuous moisture, or heat exceeding 125 degrees.

Yes, this is an excellent application for Drywall Suspension Systems. USG has a selection of designs that have been third-party verified for wind resistance. In fact, USG Drywall Suspension Systems with Securock® Glass-Mat Sheathing has been accepted by Miami-Dade County for use on exterior soffits in high wind velocity hurricane zones.

When nailing to wood construction the spacing is 7 inches for ceilings, and 8 inches for walls. When screwing into wood and steel framing the spacing is 12 inches on ceilings and 16 inches for walls. Refer to the relevant fire test to determine fastener type and spacing.

Yes, similar to most USG ready-mix joint compounds, Sheetrock® Brand UltraLightweight All Purpose Joint Compound can be used for simple hand-applied textures.

Durock™ Self-Leveling Underlayments can be used as a wear surface with a tested protective coating system. Coating systems must be tested for adhesion. The bond test and performance of coatings is the responsibility of the coating manufacturer.

Yes. These beads can be used but they must be embedded and finished with setting-type compounds.

Yes, however keep in mind that compressive strengths will be reduced when using aggregates. Aggregates should be selected based on weight considerations/appearance. Aggregates sized greater than 10 mesh should not be used, as the gypsum crystals will not bond well to them. Reinforcing materials can be used for thin casts. Glass mat and chopped glass can add flexural strength, and very small fibers can add chip resistance to castings.

We recommend using USG Durock™ Brand Tile Backer coated fiberglass mesh tape for all applications interior or exterior.

We recommend a minimum of 100 feet of hose when being pumped.

Ultimately the floor covering adhesive manufacturer must approve use of their products over USG products. Please consult with adhesive manufacturer prior to use over USG products.

Yes. USG has a design for a 2-hour Cavity Shaft Wall enclosure.

The “Installation and Application Guides” for Securock® Roof Boards are available on the product infromation site.

Firecode® Brand Compound is applied in wet form and allowed to set or harden. It is typically used in walls, floors and curtain wall slab edge conditions where strength and economy are required.

The Fire Resistance Rating does not require any joint finishing of the horizontal butt joints of the 1" Liner Panels. We do recommend for heights greater than 12 feet the horizontal butt joints be staggered for proper structural integrity of the wall system. Please refer to USG Cavity Shaft Wall System Catalog (SA926) for additional information.

Make sure wallboard is clean, firm and dry before applying corner bead and trim. Also, verify that the bead or trim is wide enough to cover any gaps in the wallboard.

We always recommend following the floor covering manufacturer’s installation instructions.

A: STRUCTO-CRETE® Panels can be supported by 18 ga. (43 mil.) or higher Cold-Formed Steel framing, SPF lumber, or Hot-Rolled Steel framing.

Typical span:

• Subfloor: 12", 16", 24"
• Roof Deck: 12", 16", 24", 32", 48"

No. Diluting Tuff-Hide is not recommended and will reduce performance of the product.

Yes.

Yes. We recommend that the splice not be located in the middle 1/3 of the span.

Please refer to System Catalog (SA926) for additional information.

When the slab extends over 2" from the interior side of the Shaft Wall that piece is there to offer protection from things falling onto the ledge and to provide safety to ensure nothing can sit or be left there. It does not have an effect on the fire rating.

No. Only the products indicated in the UL Design should be used to construct the USG Cavity Shaft Wall.

Sheetrock® Brand Tuff-Hide™ Primer-Surfacer provides installed cost savings versus traditional separate applications of a skim coat and prime coat. The product is ideal in critical light areas, or where a Level 5 or similar high quality finish is specified or desired. It is a high build durable coating that hides minor surface defects, minimizes callbacks caused by joint banding and photographing and provides a soother more beautiful paint finish than by simply using a drywall primer. In a ceiling application where a flat white finish is desired, Sheetrock® Brand Tuff-Hide™ Primer-Surfacer can be left unpainted providing an ideal final finish.

USG Durock™ Brand Self-Leveling Underlayments can be installed from featheredge to a thickness of 2-in. in a single lift. Thicker applications of up to 5 in. can be accomplished with the addition of clean 3/8-in. Surface Saturated Dry (SSD) pea gravel with no standing water. For these pours, the recommended technique is to apply pea gravel to the deep section within ¼-in. of the final grade. Make an initial pour of the USG Durock™ Brand Self-Leveling Underlayment into the gravel and using a garden rake, thoroughly mix the underlayment and pea gravel together. Allow to dry for 24 hours. Prime with USG Durock™ Brand Primer-Sealer as directed in Priming. Complete application by capping with a minimum of ¼-in. of the USG Durock™ Brand Self-Leveling Underlayment.

At SSD, the pea gravel aggregate is wet, thus requiring a reduction in the amount of water in the mixture to prevent overwatering. Ensure there is no bleeding or material segregation (settling of sand) in the final mixture. Use only clean and chemically stable aggregate. Do not use limestone aggregate or other types of potentially reactive aggregate.

Control joints are not to exceed 30 feet for walls and ceilings. The spacing for a ceiling with perimeter relief is not to exceed 50 feet.

Yes, Fiberock® Underlayment Tile Backerboard and Fiberock® Aqua-Tough™ interior panels are ideal substrates for ceramic tile and/or paint.

The required spacing is 18 inches which allows the maximum .65 NRC when using Acoustibond backer on perforated panels.

Yes. Mill-mixed USG Red Top® Brand Finish Plaster or other job-site lime/gauging plasters can be applied over Veneer Basecoats.

No, Sheetrock® Brand UltraLightweight All Purpose Joint Compound is formulated as a ready-to-use product. Simply mix and use. If adding water, use sparingly and test apply. The material characteristics of Sheetrock® Brand UltraLightweight All Purpose Joint Compound are different from other USG ready-mix joint compounds, therefore typical job-site mixing indicators do not apply.

Yes, these boards are compatible with both interior and exterior applications, and they can also be used in interior below-grade applications such as basements. In exterior applications, Durock® cannot come in contact with the ground. 

Half-inch panels must be applied perpendicular and 5/8 inches can be applied either way.

Locations and design of control joints should be specified by the design professional for the project.

Yes, Sheetrock® Brand UltraLightweight All Purpose Joint Compound can be used for skim coating.

Yes. 5/8" Fiberock Brand Abuse-Resistant Panels can be used in a UL-rated assembly that requires the use of Type X.

Sheetrock® Brand Texolite™ Wall and Ceiling Texture Paint dries to a hard, durable natural white finish.

Two layers of 5/8” Sheetrock® Firecode® Type X panels may be installed with the main T’s 48” OC, the cross T’s 24” OC, and 12 gauge hanger wires attached to the main T’s at 32” OC.

Yes. USG Cavity Shaft Wall vertical vent shaft assembly rated 2 hours per UL Design Number U529.

Firecode® Brand Acrylic Firestop Sealant is applied from a caulk gun and is typically used for floor and wall penetrations where movement is anticipated and flexibility is a requirement.

The maximum gap should not exceed 1/8 of an inch.

The best grids to use in an area accessible to moisture are the Donn® AX™ Acoustical Suspension System or the Donn® ZXLA™ Acoustical Suspension System.

To remove a cross tee, push up on the main tee with your thumbs (where the cross tee is connected) and rotate it until the cross tee pops up and out of the slot.

It takes 12-14 pounds of force to install a cross tee.

For residential installation 18-gauge wire is required. For commercial installation 12-gauge wire is required.

All systems must be installed and tested in compliance with ASTM C636.

For commercial installations, hanger wires should be spaced between 4' on center along the main tees.

Minimum clearance is 4", which allows ceiling tiles to be inserted and removed freely.

Facing the main tee splice place your left hand near the left side of the splice and right hand near the right side of the splice. Using a shearing motion, push with your left hand and pull with your right hand. This disconnects the main tee splice. Be sure to straighten the end tabs before attempting to reconnect.

A: The carpenter typically leads the installation of STRUCTO-CRETE® Panels, which allows you to eliminate the many trades needed to pour concrete.

A: Review the installation guide.

A: The side with the glass-mat is the top side for floor applications.

Clean sides and lid of container so no dried compound falls into the mixture. Level joint compound surface with a knife and cover container tightly. If storing, cover leveled surface of joint compound with approximately 1/2" of clean water and cover container tightly. Pour off water before reusing joint compound. Do not store in direct sunlight and protect from extreme heat and cold. The shelf life of an unopened container is up to nine months under proper storage conditions.

For most interior applications, Durock® Brand Cement Board Panels are not affected by water and do not need to be waterproofed. Durock® is water durable but not waterproof. If you're looking for added protection to water sensitive material behind the Durock®, you may consider adding a waterproofing membrane. TCNA guidelines recommend the use of a waterproof membrane in interior wet areas. 

For exterior applications, consult your design professional as vapor permeance is climate dependent. 

Relax the serrated edge by pre-creasing or folding the strip. This ensures smooth removal of the masking and results in a clear tear that will not damage the trim.

Yes. Each coat must be completely dry before applying the next.

Gypsum panels can be installed horizontally or vertically. Installing the board horizontally lessens the total amounts of joints to be taped by 25%.

Sheetrock® Brand Durabond® Setting-Type Joint Compounds and Sheetrock® Brand Easy Sand™ Lightweight Setting-Type Joint Compounds are the best products to use for repairing cracks.

If you want to use a ready-mixed joint compound, Sheetrock® Brand All Purpose Joint Compound works well.

Yes, different joint compounds can be used over each other.

No, different joint compounds should never be mixed with each other.

Remove the old plaster down to the wood lath, staple metal over the existing lath and apply Red Top® sanded conventional basecoat over the metal lath. Any USG finish plaster can be applied over the basecoat plaster for a final coat.

Blistering joints are the result of not having enough joint compound under the tape. The best way to repair blistering joints is to open up the blistered area by slitting the tape. Fill the cut with joint compound and press tape back in place with knife blade.

The coverage rate is comparable to other USG ready-mix joint compounds. You can anticipate approximately two 4.5 gallon pails of Sheetrock® Brand UltraLightweight All Purpose Joint Compound to finish 1000 sq. ft. of gypsum wallboard.

Paper-faced beads provide superior adhesion to joint compound, primer and paint. They have a lower bead height than bare faced beads and trims. This requires less consumption of joint compound when coating the trims. They have an almost non-existent chance of leaching rust through the joint compound and finish paint. Tape-on trim rarely edge cracks, a common problem with nail-on and staple-on bead and trim.

The maximum gap should not exceed 1/8 of an inch.

For residential installation 18-gauge wire is required. For commercial installation 12-gauge wire is required.

Fly ash often is used as a filler in concrete. When used at excessive levels, fly ash and concrete has been cited as one of the reasons for excessive moisture in concrete slabs.

In Durock™ EcoCap™ Self-Leveling Underlayment, the fly ash is not used as filler but rather as a source of aluminum and silicon in the geopolymer reaction that takes place. In this case, the fly ash contributes significantly to the strength, self drying and setting characteristics of the product due to the geopolymer reaction.

Portland cement is one of the largest contributors of CO₂ emissions. For each ton of Portland cement made, one ton of CO₂ emissions is produced. The Geopolymer binder of Durock™ EcoCap™ is made using a large quantity of industrial byproduct (fly ash) that is instrumental in keeping the CO₂ contribution of the product to very low levels. Compared to Portland cement, the net reduction in CO₂ emissions resulting from the Durock™ EcoCap™ binder is approximately 80%.

When the proper type of lighting fixture is used with a high LR ceiling, there can be savings in both initial construction costs as well as long-term energy costs. The concept is to use the ceiling to reflect light back into the occupied space.

NRC is very important in open office plan environments where there are few full height walls to help absorb or block sound.

LR stands for light reflectance. It is a measure of the percentage of light which is reflected off of a given panel surface. Typically, the whiter and smoother the ceiling panel, the higher the LR value.

NRC stands for Noise Reduction Coefficient. It is a measure of how much sound is absorbed by a given material. It is listed as a decimal and relates to percentage sound absorbed.

These categories refer to ASTM Test E 1264.
Type refers to the base material of the panel.
Form refers to the manufacturing process of the panel.
Pattern refers to the type of texture or pattern in the panel.

Class A signifies that a panel attained a flame spread index of 25 or less (based on 100 for untreated red oak) when tested in accordance with the Standard ASTM E 84. The Firecode® brand signifies that the panel has been classified as a protective membrane in a floor-ceiling or roof-ceiling assembly in accordance with the Standard ASTM E 119. All Firecode® protective membranes offered by USG have attained a Class A rating.

USG has been manufacturing quality building material products for 110 years. We have been selling cement-based products for more than 30 years and have been making underlayment products since the 1970’s. We have an industry-leading R&D center in Libertyville, Illinois, and have several members of our technical staff who have PhD’s in cement-related fields.

Set time is an industry test that identifies when plaster slurry has developed enough strength to prevent a Vicat needle from penetrating through a thin plaster patty. This is helpful in defining the working time or “open time” for a plaster mix. Please note that plaster becomes unworkable or “stiff” well ahead of the actual set time, often in half the time for the slurry to set.

Wet-felted panels are typically mechanically perforated and fissured. They are very dense and more economical than other types of ceiling panels. Cast ceiling panels are non-perforated and are manufactured in a different “cast” process, hence its name, that enhances their surface appearance and provides excellent sound absorption and durability.

UL Design Numbers U415, U438, U459, U467, U469, and U492.

CAC is important when there is a need for privacy between spaces.

Paper-faced beads provide superior adhesion to joint compound, primer and paint. They have a lower bead height than bare faced beads and trims. This requires less consumption of joint compound when coating the trims. They have an almost non-existent chance of leaching rust through the joint compound and finish paint. Tape-on trim rarely edge cracks, a common problem with nail-on and staple-on bead and trim.

"X" Technology is a unique manufacturing method which was developed by and introduced to the market by USG in 1989. This technology is used to produce ceiling panels with sag resistance and exceptional acoustical performance found in USG’s line of ceiling products with ClimaPlus™ Performance.

CAC stands for Ceiling Attenuation Class. It is the measure of the blocking of sound through one ceiling plane, into the plenum above, and back through the other ceiling plane to an adjacent space.

Consistency is defined as the number of parts of water, by weight, required to produce slurry of specified fluidity when mixed with 100 parts of plaster by weight. Consistency is product specific, but generally, the lower the water addition, the thicker or less flowable the slurry will be. The more water you add, the “looser,” more free flowing the slurry will be. As consistency increases the strength decreases.

Correct, the only difference is that USG Hydrocal® 105 is yellow and USG Hydrocal® 106 is white.

No. On the contrary, USG Calcium Sulfate Feed Grade is used as a calcium enrichment for animal feed. USG Food and Pharmaceutical grade gypsum products are used in many human food and pharmaceutical applications. Gypsum should not be harmful if used appropriately.

Yes, USG Beta Dental Special is manufactured to a higher level of brightness (whiteness) standard than other beta plasters.

Flat ceilings constructed of gypsum board that are screw-attached to suspension members that support a ceiling on one level extending from wall to wall, are generally exempt from acoustical seismic construction requirements such as: perimeter end wall clearance, perimeter hanger wires, horizontal restraint and vertical splay bracing. This is due to the diaphragm strength achieved by screw-attached gypsum board. Gypsum board ceilings that do not extend perimeter to perimeter, or have multiple levels, may require seismic bracing depending on the local code interpretation.

These three formulas are controlled with specific accelerators and retarders at the manufacturing plant which will consistently achieve the advertised set time range for each product. Manipulating set time with water temperature and mixing is not as accurate and predictable.

Gypsum will provide calcium and sulfur to your soil and won't buffer the pH of your soil like limestone products. Gypsum can also help open air and moisture channels in the soil, improving soil struture and reducing run-off. Gypsum can also act to counter damage caused to plants by salt.

Yes. Because of its whiteness, the anhydrous form of calcium sulfate — such as that found in CA-5™ Calcium Sulfate Filler — is used successfully to extend Ti02 at a much lower cost.

The setting time of USG Hydrocal® X-21 Gypsum Cement provides low expansion, which benefits further formulation.

Yes, USG Prostone™ SM may be colored using appropriate pigments.

Please contact USG Customer Service at 800-621-9523 extension 1 for information.

No it is not approved for these types of application.

Dihydrate calcium sulfate (CaS04•2H20), contains about 20% chemically combined water, othewise known as water of crystallization. Anhydrous calcium sulfate (CaS04), contains no water of crystallization.

No, not at this time. Please contact your sales rep to discuss how to achieve a desired set time.

Yes, USG Hydrocal® C-Base™ Gypsum Cement is higher in strength than USG Hydrocal® B-Base™ Gypsum Cement.

Yes, this is an excellent application for Drywall Suspension Systems. USG has a selection of designs that have been third-party verified for wind resistance. In fact, USG Drywall Suspension Systems with Securock® Glass-Mat Sheathing has been accepted by Miami-Dade County for use on exterior soffits in high wind velocity hurricane zones.

It is best to use a minimum of .70 NRC and up to .80 - .90 NRC panel for this type of application.

Gypsum is beneficial to crops that require a lot of calcium and/or sulfur such as peanuts, blueberries, tomatoes, potatoes, evergreens, and many other crops.

USG food and pharmaceutical grade calcium sulfate filler products conform to FDA Regulation 21CFR184.1230, and are affirmed as GRAS (Generally Regarded as Safe). Calcium sulfate filler products are also safe to use in food packaging applications.

No product coloring is offered beyond the base color of USG Hydrocal® 105 Gypsum Cement.

USG Ben Franklin™ products, USG Sof'n-Soil® and USG Calcium Sulfate Feed Grade are certified organic by the Organic Materials Registry Institute (OMRI) and many state organizations.

Sheetrock® Brand Gypsum Lay-In panel is approved by both the USDA and the FSIS for use in commercial kitchens.

The best grids to use in an area accessible to moisture are the Donn® AX™ Acoustical Suspension System or the Donn® ZXLA™ Acoustical Suspension System.

Yes. USG has more than 60 UL designs where Drywall Suspension Systems are listed. In fact, the system can be used in place of cold rolled channel and furring channel in any UL fire rated design.

Yes, U416.

The design of structural members containing fire damper assemblies is normally the responsibility of the fire damper manufacturer, and not USG. This is for proper operation of the fire damper during a fire.

USG Cavity Shaft Wall

The USG Fire Stop System with Firecode Compound and safing insulation works exceptionally well with metallic pipe, conduit and electrical cable. The systems also works in combination with intumescent wraps and collars to form an effective Firestop at through-penetrations for materials that can collapse, decompose or disintegrate in fire, such as Schedule 40 plumbing materials made of Acrylonitrile-Butadiene-Styrene (ABS), Polypropylene (PP) or Polyvinyl Chloride (PVC).

Class A signifies that a panel attained a flame spread index of 25 or less (based on 100 for untreated red oak) when tested in accordance with the Standard ASTM E 84. The Firecode® brand signifies that the panel has been classified as a protective membrane in a floor-ceiling or roof-ceiling assembly in accordance with the Standard ASTM E 119. All Firecode® protective membranes offered by USG have attained a Class A rating.

USG Cavity Shaft Walls provide UL tested 1- to 4-hour fire resistance.

Yes. Insulation can be added without any decline in fire resistance. Also, if that same assembly requires insulation it must be added.

Elevator shaft walls are considered working walls. By that, they flex both inward and outward as the elevator passes by. This flexing causes the runner track to fail due to fatigue. Tests have shown that to oscillate one million cycles the gauge of the runner has to be increased to 24.

A shaft wall can be built in front of the existing partition. This system can be used for ratings of up to 4 hours.

No. The ceiling system achieves a time rating based on the entire assembly which includes roof deck or floor deck assembly.

UL Design Numbers U415, U438, U459, U467, U469, and U492.

When nailing to wood construction the spacing is 7 inches for ceilings, and 8 inches for walls. When screwing into wood and steel framing the spacing is 12 inches on ceilings and 16 inches for walls. Refer to the relevant fire test to determine fastener type and spacing.

Joint compound does not have a fire rating by itself, but does meet ASTM C475. When fire testing a wall the fire rating is not for individual products, but for all the system components together. USG Joint Compounds are used in numerous fire-tested assemblies. These are outlined in USG Publication SA100 Construction Selector.

Sheetrock® Brand Gypsum Liner Panels & Sheetrock® Brand Gypsum Panels (Firecode, Firecode C, or Ultracode Core. Please refer to the appropriate fire-resistance design for specific panel selection.

Yes. It is important to note that insulation cannot be arbitrarily added to a fired rated floor ceiling assembly that was tested without insulation. The use and location of insulation in the assembly can dramatically affect fire performance because insulation traps heat (even if it is being used for sound purposes) and can cause premature failure.

USG has UL-tested assemblies where insulation is installed directly on the back side and supported by the gypsum board. Other drywall grid systems do not have this feature so careful selection is important.

There is no rating on a board by itself. Fire ratings are allocated only to systems.

All of the recognized codes require the materials and methods used be "approved" typically by an independent and recognized testing laboratory such as Underwriters Laboratories or Factory Mutual. Generally, these materials include common filling or damming materials such as mineral fiber, backer rod or ceramic fiber insulation, and a noncombustible sealant or compound. Approved systems and materials now are outlined clearly in Underwriters Laboratories Fire Resistance Directory. See USG Firestop Systems folder SA727 for tested systems and products.

Yes, 30-minute single layer steel and wood framed, and one hour double layer steel framed fire-rated wall systems (UL Design U407).

When nailing to wood construction the spacing is 7 inches for ceilings, and 8 inches for walls. When screwing into wood and steel framing the spacing is 12 inches on ceilings and 16 inches for walls. Refer to the relevant fire test to determine fastener type and spacing.

Please refer to UL's database for specific UL information, we also have information for UL on http://securockroofboardsblog.usg.com.

The Fire Resistance Rating does not require any joint finishing of the horizontal butt joints of the 1" Liner Panels. We do recommend for heights greater than 12 feet the horizontal butt joints be staggered for proper structural integrity of the wall system. Please refer to USG Cavity Shaft Wall System Catalog (SA926) for additional information.

The building codes require Firestop of all penetrations through fire-rated assemblies. Typically this includes floor/ceilings, elevator shafts, stairwells, corridors, etc. Of course, since the objective of Firestop systems is to contain fire to the area of origin, it is wise to seal all through-penetrations. Firestop also is needed at other joints, voids or gaps in fire-rated assemblies, at air passages and at plenums concealed within floor assemblies.

See USG Fire Stop Systems folder SA727 for tested systems and products.

Yes. 5/8" Fiberock Brand Abuse-Resistant Panels can be used in a UL-rated assembly that requires the use of Type X.

The limiting height is based upon the stud size and gauge, allowable deflection and air pressure load. System Catalog (SA926) contains a limiting heights chart.

Place board inside, under cover and stacked flat on a clean floor in the centers of the largest rooms. All materials should remain in their packaging until ready for actual use. Place gypsum boards intended for use on ceilings on top of the pile since they will be used first. Do not stack long length boards on top of short length boards.

For Durock™ Self-Leveling Underlayments, USG uses 50 lb. bags stacked 56 bags per pallet. We also can use high volume “super sacks” for larger jobs.

Durock™ Fast Finish Floor Patch is available in 10 lb. bags with 208 bags per pallet.

Fiberock Panels are heavy and should be stacked flat on the floor. Serious injury can occur from falling panels.

USG recommends that these products perform best when stored at temperatures below 110°F, protected from moisture or humidity and processed within one year of the date of manufacture. After this period of time, agglomerates may form which would affect the free flowing nature of the product. At recommended storage conditions, the one year recommendation relates primarily to processing, but combined moistures and reactivity could also be affected in extended storage.

Durock™ Self-Leveling Underlayment products are good for six months from the date of production.

Plaster can be stored 3-6 months if it is stored in a cool, dry place, protected from extreme heat and cold, direct sunlight and at a temperature above 45°F (7°C).

Sheetrock® Brand Gypsum Panels must be protected from exposure to excessive or continuous moisture and the elements before, during and after installation. Storing outdoors uncovered is not recommended.

Storage time of materials at the job site should be as short as possible, and environmental conditions should be as near as possible to those specified for occupancy. Excess humidity during storage can cause expansion of material and possible warp, sag, or poor fit after installation. Chemical changes in the mat and/or coatings can be aggravated by excess humidity and cause discoloration during storage, even in unopened cartons. Cartons should be removed from pallets and stringers to prevent distortion of material. Long-term (6-12 months) storage under uncontrolled environmental conditions should be avoided.

Store Fiberock® indoors and protected from the elements. Protect them from extreme heat and cold and do not expose to direct sunlight.

The shelf life of an unopened container is up to nine months from the date of manufacture under protected storage conditions.

Yes. Handle panels in such a manner as to ensure against racking, distortion or physical damage of any kind.

The warranty is effective for 30 years from the date of the installation in the structure. See complete warranty for details:

• Tape-On Warranty
• Nail-On Warranty

Fiberock® Brand Aqua-Tough™ Underlayment has a 20-year limited warranty. See complete warranty for details.

We offer a one-year, product performance warranty over approved substrates. Longer warranties may be available on a job-by-job basis

They offer a 12-month exposure warranty, and they can be used in any fire-rated cavity shaft wall and separation wall system assembly.

There is a lifetime warranty on any ceiling system that is used in conjunction with our tile and grid. All grid is lifetime when used with USG tile, however not all tile is lifetime when used with USG grid. See complete warranty for details.

Ten years. See complete warranty for details.