Richmond Justice Center was a new construction and a hot fluid applied PMR (Protected Membrane Roof) system with split slab waterproofing on the top floor of the building and chrystalline waterproofing in the elevator shafts. In a PMR system, fluid-applied hot rubberized asphalt (HRA) is first applied to the concrete deck. Protection sheet, insulation, and filter fabric are installed and topped with ballast to complete.
PMR systems are advantageous because the roofing membrane is protected from heat and UV degradation by the insulation and ballast. This also lessens heat shock to the membrane when the temperature rapidly increases or decreases. These layers add an extra level of protection from foot traffic and punctures to the membrane. The hot rubberized asphalt waterproofing, a monolithic membrane, prevents any standing water from finding a path through seams since it’s seamless. It’s also much easier to locate a (potential) leak since the membrane is directly adhered to the concrete deck instead of over the insulation.