Flat and low-slope roofs in Tampa Bay
The Florida-room addition, the mid-century flat section, the carport: ponding water, a membrane past its life, and the leak at the wall. Get connected with a Florida-licensed roofing contractor in Hillsborough or Pinellas who works flat roofs.
Flat roofs around Tampa Bay are mostly additions: the Florida room, the carport, the 1980s bump-out on a 1950s block ranch house in St. Petersburg, Largo, or Pinellas Park, and the low-slope sections of mid-century houses in Carrollwood. They leak first because they hold water, and they leak at the wall where the flat section meets the pitched roof. Milton's 15 to 20 inches of rain on southern Pinellas found every one of them.
Call and get connected with an independent, Florida-licensed roofing contractor who works flat roofs in your area. Say what the surface is (gravel, rolled roofing, a white membrane) and where it leaks; the contractor calls you back to schedule the inspection.
Repair or replace
A seam, a flashing, or a penetration on an otherwise sound membrane is a repair, done with a patch of the same material and a written warranty on that spot. Chronic ponding, a membrane that is brittle or blistered everywhere, or wet insulation under the surface (a contractor can find it with a moisture meter) is a replacement.
The 25% rule (Statute 553.844) applies to flat sections as it does to any roof section: more than a quarter replaced in a year brings the section to current code, which for a flat roof usually means new tapered insulation for drainage, new drains or scuppers, and a new membrane, permitted and inspected. Since 2022, a section built or replaced under the 2007 Florida Building Code or later only needs the repaired portion brought to current code.
The systems used here
- Modified bitumen (torch-down or self-adhered): the common residential flat roof around the bay, granulated cap sheet over a base sheet; a 15-to-20-year life.
- TPO and PVC single-ply membranes: white, reflective, heat-welded seams; lower attic heat, and the choice on larger flat sections and commercial work.
- Silicone or acrylic coatings over an existing membrane: a maintenance option that extends life on a sound roof, not a fix for a wet one.
- Tapered insulation and crickets: what stops the ponding; a flat roof that holds water two days after rain is designed wrong or has settled.
The transition and the permit
The detail that decides whether a flat addition leaks is the wall flashing where it meets the main roof or the house: counter-flashing let into the wall, not caulk. Ask the contractor how they detail it. Flat-roof replacement is a permitted job in every jurisdiction around the bay, and the contractor pulls the permit in their own license.