TPO Roofing in Pompano Beach, FL

An adhered sheet is glued to the insulation or cover board across its whole back, which Carlisle describes as the highest level of durability and wind uplift protection among its TPO systems. Some sheets come with the adhesive factory-applied; one Florida product approval lists a self-adhering TPO in 45 or 60 mil, lapped about 2 inches and hot-air welded at least 1-1/2 inches wide. It's also the priciest of the three methods: guides put adhered membrane at $2.80 to $3.50 a square foot for material alone.

Here the sheet is screwed down through round plates along one edge, and the next sheet laps over the fasteners and is welded shut. It's the most widely installed method in commercial roofing, and Carlisle pitches it at areas with moderate winds. In the HVHZ the fastener spacing isn't a crew's call: it's the pattern set in the roof system's product approval. Material runs about $2.00 to $3.10 a square foot, depending on thickness.

Induction welding (RhinoBond or Isoweld) uses coated plates that hold down the insulation and then grab the membrane from underneath, so no screw ever passes through the sheet. On one maker's spec:

• 6 plates per 4 by 8 foot board in the field, 8 around the perimeter
• a heating cycle of a few seconds per plate from a tool set on top of the sheet
• a magnet left on each plate for at least 60 seconds
• hot-air welded laps of at least 1-1/2 inches

The grid spreads wind load over more points than seam fastening, and Sika says it cuts membrane flutter.

TPO repairs are heat-welded work: a patch over a puncture, a re-weld of a lap that has opened, new flashing at a curb or drain. Guides put flat roof repair on TPO at $2 to $9 a square foot, and flashing work at $200 to $500. Old membrane is the catch: sheet exposed for about seven days or more needs a weathered-membrane cleaner before a new weld will hold. Like any roof repair in Broward, it needs a permit; see roof repair.