The construction process requires meticulous attention to detail and is incredibly competitive. Every day, contractors are being tasked with finding new ways to cut costs and protect margins without sacrificing quality or owner satisfaction.
The search for better, faster and more efficient construction methods drives innovation and has brought about radical changes in building materials and construction technologies. Contractors must consider all aspects of system performance in order to implement new construction practices in a manner that truly delivers the desired build faster, more efficiently and at a lower cost.
Prior to any build, jobsite climate, available resources and schedule demands must be considered. Armed with this knowledge, architects and contractors can make educated decisions on which method of construction to use — traditional or pre dry-in. Each method has pros and cons, and there are many instances in which one is preferred over the other.
Any discussion of pre dry-in construction should begin with the original concept of top-down construction. Pre dry-in construction means installing the interior of a structure prior to sealing it off from the elements. It is also commonly referred to as “pre-rock,” “top-down” or “topping-out” construction. All of these terms refer to installing some portion of drywall in advance of making the structure weather tight as in conventional industry practice. This method of building is relatively new in the industry; it effectively increases efficiency, lessens overall costs and reduces scheduling conflicts.
An important factor to consider with pre dry-in construction is that specially formulated moisture- and mold-resistant gypsum panels should always be used. This is essential because the panels at the perimeter of the building are more exposed to the elements; standard paper-faced gypsum board is not suitable for weather exposure.
The mold and water resistance properties of glass-mat panels are considered superior to water-resistant paper-faced gypsum boards. As a result, glass-mat gypsum panels have become the preferred panel for weather-exposed applications, where they have performed well. This logic is now being extended to interior spaces where pre dry-in construction has come to include hanging the wallboard over the full floor-to-ceiling height of the wall. It is no longer limited to just the partial wall of the plenum space above the ceiling plane. This practice creates much greater exposure risks, even for glass-mat faced gypsum panels, that must be understood and considered carefully.
Pre dry-in construction requires close coordination between all trades working on a job site. Drywall tradesmen first install the metal framing and then hang interior wallboard in the plenum above the finished ceiling plane. Then the mechanical, electrical and plumbing tradesmen (MEP) install the ducts, conduit and pipes that penetrate the plenum walls. In the plenum space, joint finishing can usually be done quickly and simply by fire-taping the joints. Hence, pre dry-in construction can speed construction and reduce costs while simultaneously improving quality and finish.
In traditional construction practices, MEP tradesmen work first, and then drywall contractors begin their installation after the building has been enclosed and is weather tight. Traditional construction creates a complicated process of installing wallboard around duct and pipe penetrations. This creates the possibility for quality and fire-resistance ratings to be compromised at these difficult-to-reach joints and penetrations.
Traditional construction is required by code in some locations, but the efficiency gains of pre dry-in construction are preferred in others.
The pre dry-in practice creates much greater exposure risks, even for glass-mat faced gypsum panels, that must be understood and considered carefully. However, pre dry-in construction offers yet another tool that a contractors and architects can employ to speed construction, reduce costs and improve quality by eliminating certain drywall installation and scheduling problems. Still, it should not be considered the only construction option, as there are instances in which traditional construction practices will be the most effective. By considering both methods, builders can gain a complete understanding of the project and the nuances that direct which method is the best one for the job.