The Salt River Project Information Systems Building in Tempe, Arizona underwent a year-long exterior restoration. The six-story, granite-clad building included a large plaza on the second level and terraces on several floors.
At the time of initial construction, built-in planters had been lined with hot rubberized asphalt as waterproofing. Over the years, the material was compromised by plant and root growth. The planters needed a new waterproof lining that could be applied without disrupting building occupants with construction noise and fumes. Since many cities now prohibit hot-melt kettles on the rooftops of occupied structures, a different high-performance waterproofing membrane was preferred. Further, as the planters were only 18 inches wide in some cases, the waterproofing needed to provide the ultimate in protection despite the application restrictions.
The consultant, Exterior Consulting Innovations Inc. (ECI), dismissed using hot rubberized asphalt in the planters and weighed several options. Though a sheet-applied membrane was initially considered, the extreme heat in the Arizona sun would have made the adhesive-backed sheets even more difficult and messy to apply. The preferred alternative was a high-performance, cold fluid-applied waterproofing membrane, which would provide aggressive adhesion and a monolithic, continuous surface without seams to eliminate the opportunity for leaks.
ECI was familiar with Tremco’s TREMproof 250GC fluid-applied elastomeric waterproofing membrane. It had the ease of application, adhesion characteristics and compatibility with other asphalt-based systems that make it the perfect choice for renovation projects. After successful testing, ECI applied TREMproof 250GC in three 60 mil lifts to a system thickness of 180 mils. Since TREMproof 250GC can be applied by roller, squeegee or even trowel, ECI had many options for making sure the waterproofing material was applied evenly and thoroughly in the planters. In total, approximately 900 gallons of TREMproof 250GC were applied to all 140,000 square feet of planter and terrace areas.