Delta Innovative Services and JE Dunn Construction partnered to win the General Services Administration Bannister roofing project. This highly complex job involved working on an occupied, high-security site over more than a year. Extensive product evaluations took place to find the best system for this massive, flat expanse that needed to create slopes to push water to the drainage system, to ensure the integrity of the roof.
Before the nearly half million square feet of new roof went on, tear-off of the existing sun-baked pitch had to take place. Handling coal tar pitch that is more than 20 years old is dangerous since it is a heat sensitive material that can cause irritation to the skin and eyes. Balancing removal of the pitch with bringing new materials onto the roof required careful calculation of the “old” roof ’s weight limitations and restrictions. Given the massive size of the project, tear-off of some sections and installation of others were happening simultaneously, adding to the logistical complexity of the project.
In order to keep the crew safe during tear-off of the old coal tar pitch, Delta Innovative Services decided that the best approach was to start work hours before daybreak to avoid the sun’s heat, some mornings as early as 2:00 a.m., and increase Delta’s team from nine to 15 workers in protective clothing.
With the weight limitations in mind, the JM system was selected by the contractor and the consultant to help mitigate as much waste as possible. The deck was primed with JM Asphalt Primer then JM DynaBase® XT was rolled out over hot asphalt to create a vapor barrier. Over the vapor barrier, tapered ENRGY 3® adhered with RS Urethane Adhesive was installed. The tapered design was a key component of the new roofing solution, allowing water to flow properly to the drains, and it addressed the zero-slope condition associated with the old system. On top of the ENRGY 3®, Invinsa® Roof Board was installed followed by a layer of DynaBase® XT and JM DynaFast® 180 S, both adhered with MBR Cold-Appli-cation Adhesive. Finally, JM DynaLastic® 250 FR was laid out next, to relax and then adhered with MBR Cold-Application Adhesive. The teams at Delta and JE Dunn have done more than 40 jobs together over the past 32 years. General Contactor JE Dunn’s Superintendent On-site, Cheryl Luther stated that, “Delta is great at bringing solutions to the table. Getting their team together to work in the middle of the night to avoid sunlight to keep the crew safe is a great example of that.” Luther also had praise for the JM team that was a steady presence on the job site. Not just being there but being involved with a vested interest to ensure materials were being installed correctly. “Truly, JM reps do everything they can to make sure the warranty will be honored to the last day. This client was like all others; the most important issue to them is that once the job is done, they don’t have to think about the roof for years.”