TPO roofing.

TPO (thermoplastic polyolefin) comes in rolls of reinforced sheet. Seams are joined with hot air, so the laps fuse into one sheet instead of relying on tape or glue. Sheets run 45, 60 or 80 mil thick. We price 60 mil as our reference system, mechanically fastened or fully adhered, and any thickness the spec names.

The white surface reflects most of the sun that hits it. On a Texas summer afternoon that keeps the roof surface far cooler than a dark membrane, and it lowers the cooling load on the building below.

Mechanically fastened. Plates and screws hold the sheet through the insulation into the deck, and the next sheet's lap covers the row. It goes down fast and costs less. The fastener pattern tightens at the corners and perimeter, where wind pulls hardest.

Fully adhered. The sheet is bonded to the cover board with adhesive. The surface is smoother, the sheet does not flutter in wind, and it suits decks where fasteners are limited. It takes more labor and dry weather to install.

The wind-uplift rating in the spec sets the pattern, not a rule of thumb. We price the attachment the spec names and list any alternate you ask for.

We take the field area off the roof plan in square feet and the perimeter and parapets in linear feet, and we count every drain, curb and penetration. The scale is checked against a known dimension before a quantity is recorded. Each line is priced from our unit-cost database: membrane with waste, insulation layers, fasteners or adhesive, flashing, edge metal and walkway pads. An estimator approves the proposal before it goes out.