New Flat Roof Installation - White Polyfresko Single-Ply Membrane

Flat roofs in LA mean built-up bitumen (BUR), modified bitumen, single-ply membranes, or silicone coatings. They all work when installed correctly. They all fail when they aren't. We mostly install single-ply Polyfresko and silicone these days because they're the best fit for residential flat roofs in this climate.

TPO is a single-ply thermoplastic membrane that ships in large rolls and is heat-welded at the seams with a hot-air robot welder. Done right, every seam becomes a continuous piece of the membrane - there's no caulk, no adhesive, no chemistry that degrades over time. Just a monolithic sheet of white plastic across the roof.

For this project: tear-off of the old modified-bitumen roof down to deck, inspection and replacement of soft sheathing, installation of polyiso insulation (R-20) to bring the assembly up to current energy code, mechanical fastening of the cover board, fully-adhered Polyfresko membrane, heat-welded seams, and new edge metal and pipe boots. Critical details around the parapet wall got pre-fabricated Polyfresko corners and welded penetration boots from the manufacturer.

The white color reflects roughly 80% of solar radiation. For a flat-roofed home in the Valley, that's a measurable drop in attic and second-floor temperatures during summer - typically 10-20°F reduction. Title 24 requires cool-roof reflectance for low-slope replacements, and this install meets the requirement well above the minimum.