Flat Roofing and Flat Roof Repair in San Antonio, TX

Most leaking flat roofs in town have one of four culprits: water ponding in a low spot, a seam that's opened up, cracked flashing around a curb or a pipe, or hail. Flat roof repair in San Antonio is mostly those four jobs, and we handle every one of them on TPO and modified bitumen. If the roof is past patching, we'll say so.

This city has flat roofs everywhere: strip centers on Bandera Road and Austin Highway, South Side warehouses, mid-century houses in the older neighborhoods near downtown. Most were built with an inch or two of fall per ten feet, sometimes less. So when a summer storm dumps two inches of rain in an hour, the water just sits there, sometimes for days. A membrane that soaks for a week in June and bakes well past 150 degrees in July loses its seams and flashing years before the rest of the sheet wears out.

Hail is the other story. On April 12, 2016, stones up to 4.5 inches came down in Helotes, and at the time it was the costliest hail event in Texas history. Then in late April 2021, baseball-size hail punched through the middle of the city along I-10. Mod-bit holds up to that better than a thin single-ply sheet, but a two-inch stone hurts either one. If your building took a hit, our commercial roof repair crew documents it, our former adjusters run the claim, and we cover every corner of San Antonio.

Single-ply is just what it sounds like: one membrane sheet, made in a factory, rolled over insulation or cover board and welded or glued where the sheets overlap. On the San Antonio flat roofs we install, that sheet is TPO. It's white. It throws back most of the sun. And the seams get fused with hot air rather than glue, which goes a long way toward explaining why it's taken over the commercial market here. For a warehouse or a retail center, a properly installed TPO roof is what we recommend more than anything else, and we don't hand out that recommendation casually.

Our other system, modified bitumen, isn't single-ply at all. It's an asphalt sheet with polyester or fiberglass inside, put down in at least two layers, a base sheet and then a granulated cap sheet on top. Heavier. Tougher when people walk on it. It's also what most of San Antonio's older flat roofs are already wearing, so tying into one is easier. Got a low-slope section on a shingled house, or HVAC techs up there every month? Mod-bit's often the smarter pick.

Neither one works on a bad deck. When we replace a roof, we check the decking for rot and soft spots, fix the drainage where we can with tapered insulation or extra drains, and flash every curb, pipe and parapet before the first sheet goes down. Skip that prep and the new roof leaks by year two.

Property managers ask us this nearly every week. We only install these two systems, so this comparison sticks to them.

• Installation method: TPO gets mechanically fastened or fully adhered, and every seam is hot-air welded. Mod-bit goes on in layers, either torched, cold-adhered or self-adhered.
• Seams: Welded TPO laps fuse into one continuous sheet and end up the strongest part of the roof. Mod-bit laps are sealed with asphalt, and on older roofs most of the leaks turn up there.
• Reflectivity: White TPO wins easily. On a San Antonio warehouse with a big cooling bill, you'll feel that. Granulated mod-bit cap sheets run hotter.
• Foot-traffic tolerance: Mod-bit. It's thicker and harder to puncture, and that counts when somebody's servicing rooftop units every month.
• Repairability: Both patch fine. TPO welds in minutes while it's still pliable, though old, chalky TPO fights you. Mod-bit takes torch or mastic patches for decades.
• Typical lifespan: Roughly 20 to 30 years either way in Central Texas heat, as long as it drains decently and gets looked at yearly. Ponding cuts into both.
• Best for: TPO on big, open commercial roofs where energy cost and seam strength come first. Mod-bit on small low-slope parts of houses, busy roofs, and tie-ins to mod-bit that's already there.

Don't know what you've got? Snap a photo and send it. Granules and a tar smell? That's mod-bit. A smooth white or gray sheet with welded laps you can see is TPO.

It starts with a free estimate on site. Charlie Carreon, our owner, or one of our estimators gets up on the roof, pushes on the soft spots and photographs each seam and penetration. You get a written scope with two piles: fix it now, and keep an eye on it. We've finished 2,800+ projects, and Charlie's been at this for 30 years. Our scopes don't tend to fall apart once the work begins.

When hail or wind did the damage, the insurance claim moves along with the repair. Former insurance adjusters work on our in-house staff. We meet the carrier's adjuster up top and go through the scope line by line, because a flat roof claim shouldn't settle for a patch when the whole membrane is shot. Plenty of roofers drop the ball here. It's also the thing our customers bring up most in reviews.

Then the crews show up. With eight full crew teams, we've got scheduling room a small outfit doesn't. Marco P. wrote this in his Google review: "Came out for the estimate Friday, had a guy on site the next day! 100% satisfied with the quality of work." We're veteran owned, registered and insured. Take a look at our other commercial roofing work, including full replacement and HOA and multi-family projects, or request your free flat roof estimate.