A 325-unit luxury build in Irving was running behind on weather. The installer pitched a sequence the GC had never run. Six weeks of schedule came back.
The Challenge
JPI broke ground on the second phase of a development off Loop 12 in Las Colinas, next to the University of Dallas. Months in, weather had stacked delays. JPI needed weeks back on the schedule. The post-pandemic supply chain made every dependency fragile.
JPI had already specified Treadstone Elite under the gypsum floor pour. They wanted Elite for the resident-side reasons: it quiets sound between stacked units and stops water vapor and odor migration through the assembly. That specification ended up mattering for a reason no one wrote in the spec book.
The Approach: Gyp Before Drywall
After winning the contract, Cemplex Group proposed reversing the conventional sequence. Pour the gypsum floor underlayment first. Frame and drywall on top. The benefit is obvious if you can pull it off. The building dries from the inside while it is still open. Drywall and flooring subs step onto a finished, level substrate from day one. Nobody is protecting fresh floors from rain or trade traffic.
The reason this is rare in multifamily is that most gypsum underlayments compress under partition loads or chip under the wheel loads of the trades that follow. The drywall and flooring subs end up working on a damaged floor, the warranty gets complicated, and the schedule advantage evaporates inside a punch list. The sequence only works if the underlayment can take the abuse.
Why FR25 & Elite Made the Sequence Work
Two products carried the load: Treadstone FR25 and Treadstone Elite.
FR25 is a high-strength gypsum cement. Batched through Smart Batch GC-1, it placed consistently above 3,000 psi on this job, well over the 2,500 psi the Formulated Systems Warranty requires. Smart Batch matters here because the pump weighs and records sand, water, and FR25 on every batch. Field consistency stops being an operator question. The data is right there in the batch log.
Treadstone Elite is the sound-reducing membrane under FR25. It is virtually incompressible. That property is what made gyp-before-drywall safe on this job. Wall loads from above did not crush the assembly, and the wheel traffic from later trades did not damage it. The specification JPI wrote for resident comfort turned out to be the structural reason the schedule sequence held.
What Changed on the Schedule
Beyond the floor pour rate, two wins came out of the reversed sequence:
Cured Elite is impervious to water from open windows or uncapped roof penetrations, so floor protection from rain and trade traffic went to zero.
Drywall installation came after the building was dry, which essentially eliminated mold remediation risk.
The Other Scope: 600 Balconies
While the gypsum work ran indoors, Cemplex was waterproofing more than 600 balconies on the exterior with the Elevation system: S60 sheet membrane, Embed Pans, and TTPs. Same crew and supplier as the gypsum work. The Elevation system covered the deck, the slope, the drain pans, and the railing post penetrations under one warranted assembly.