Skip to content 
Flat roofs don’t warn you — one storm and the ceiling stain shows up a week later. Call Top Quality Exteriors at (314) 618-8888 and we’ll walk your Florissant porch or garage roof, give you an honest TPO quote, and pull the city permit for you.
Flat-roof problems on Florissant homes rarely wait — a leaking porch addition over the kitchen or a ponding garage roof off New Halls Ferry Rd can soak insulation and drywall in a single storm. Roughly 75% of the city’s housing was built between the 1940s and 1960s, and the low-slope add-ons that came later now sit on tired modified bitumen or brittle rubber membrane. Top Quality Exteriors installs single-ply TPO flat roofing built for the hail, heat, and freeze-thaw cycles that north county sees every year on these aging ranch footprints.
Our crews mechanically fasten or fully adhere white reflective TPO membrane over new ISO insulation, heat-weld every seam, and finish with code-required drip edge, pre-formed corners, and reinforced flashing at every curb, chimney, and skylight. Because many Florissant garages and additions share a shingled main roof, we often pair this work with full roof replacement in Florissant so the whole system comes under one 36-month workmanship warranty. Permits, drip edge, and Code 500.330(18) matching are handled by our office.
A proper TPO install starts with tear-off down to the deck, then a thorough look at the substrate below. On the 1940s-’50s ranch belt along Lindbergh Blvd and Charbonier Rd, we routinely find 1x board decking under old asphalt or modified bitumen — and under Florissant code, warped, cracked, or delaminated boards are deemed non-nailable and must be replaced before any new membrane goes down. From there we lay 1/4-inch per-foot tapered polyiso to kill ponding, mechanically fasten or fully adhere a 60-mil TPO sheet, and heat-weld every lap and penetration flashing. Perimeter metal, inside-corner wraps, and pre-fabricated pipe boots match the thickness and color submitted for the Building Commissioner’s sample approval under Code 500.330(18). On larger low-slope sections like strip retail off New Halls Ferry Rd or the flat roof over a church hall, our commercial roofing in Florissant crew handles the same scope at scale. One Florissant permit, one crew, and one 36-month workmanship warranty.
Replacing a flat roof in Florissant isn’t a weekend DIY — the city requires a permit, drip edge, and a Building Commissioner sign-off on sample materials. Here’s exactly how our crews handle a TPO job from first phone call to final walk-through.
We walk the roof and probe decking from the attic side when safe. The estimator photographs ponding, failed flashing, and seam splits. You get a written quote inside 48 hours.
Membrane, metal edge, and flashing samples go to the Florissant Building Commissioner for sign-off under Code 500.330(18). You review color and gauge. Our office files the permit.
We strip the membrane to the deck and check every board. Sheathing deemed non-nailable under Florissant code is replaced on the spot. Then we lay tapered polyiso to kill ponding.
We fasten or adhere a 60-mil TPO sheet to the new polyiso. Every seam and penetration is heat-welded with a hot-air robot. Perimeter metal and pre-formed corners finish the roof.
Our foreman walks the roof with you, probes seams, and confirms every drain and curb. The Florissant inspector signs off. You get warranty paperwork and a full photo set emailed.
Top Quality Exteriors has 52+ team members and 7+ years of combined industry experience serving north St. Louis County from our Creve Coeur office at 12645 Olive Blvd. We are an Owens Corning® Preferred Contractor and a BBB-accredited business with an A+ rating, which matters on flat work because a bad seam leaks silently for months before you see a stain. Every TPO job we pull in Florissant is a licensed, permitted, insured install — no handshake side crews.
On the mid-century ranch belt that dominates Florissant, most flat sections sit over an old porch, breezeway, or back addition — spots that cost more to fix after a leak than to re-roof properly. Our estimators quote honestly: insulation, decking replacement where Florissant code deems old boards non-nailable, drip edge, and heat-welded seams. If your roof took hail on May 19, 2025, our storm damage roofing in Florissant team meets the adjuster for you.
A single-ply TPO roof on a modest Florissant porch or garage runs less than most owners expect — the material cost is affordable, the installs are fast, and most Florissant jobs clear in one or two days. What moves the number is what sits under the old membrane. On 1940s-’50s ranches, decking replacement is the honest variable: Florissant code requires non-nailable boards to come out, and that line gets quoted in writing before we start the tear-off.
Financing through Hearth or GreenSky keeps the monthly affordable even on a full tear-off plus decking replacement, and our 36-month workmanship warranty is firm on every job — not an add-on. Many north county owners roll a flat porch roof into a larger project; pairing TPO with asphalt shingles over the main house usually drops the per-square cost. We won’t quote a lowball number only to spring surprises after the dumpster lands in your driveway on Charbonier Rd.
Every credential we carry is a commitment to quality, safety, and your peace of mind — on every project, in every state we serve.
