Commercial Roofs in Forest Hill: Low-Slope Systems Built for Hail Country

Most commercial buildings use low-slope or flat roofs covered with a membrane, metal panels or a built-up system. Water does not run off as fast as it does on a pitched roof, so drains, scuppers and seams do most of the work.

When one of those fails, water spreads across the deck before it shows inside. By the time a ceiling tile stains, insulation under the membrane may already be wet. See flat roof drainage systems for how the water should leave.

Low-slope roofs also carry more equipment than homes do: HVAC units, vents, conduit and sometimes walkways. Every curb and penetration is a seam that has to stay sealed. Most commercial leaks we see start at one of those details, not in the open field of the membrane.

NOAA's Storm Prediction Center logged 117 hail reports within 10 miles of Forest Hill from 2015 through 2024, with 22 of them at 1.75 inches or more. The largest was 3 inches, on March 16, 2023. On a flat roof, stones hit at full force instead of glancing off a slope.

Hail can puncture membranes, crush insulation boards underneath and dent rooftop units and metal panels. The damage is often hard to see from the edge. Owners and property managers in Tarrant County should plan a walk of the whole roof after big storms, not just a look at the ceilings.