TREMDrain™ DPI is an optional drainage, protection and insulation board designed for use primarily with TREMproof® 260 Spray-Applied Waterproofing Membrane. TREMDrain DPI’s unique and proven glass fiber design promotes efficient water drainage and the retention of the board’s Rvalue. The semi-rigid nature of the board acts as a protection course for the TREMproof 260 waterproofing membrane. TREMDrain DPI is an excellent way to address below-grade energy efficiency needs. It fulfills requirements specified in ASHRAE 90.1 which call for belowgrade walls to have “a rated R-value insulation not less than” what is specified for the climate zone.