Commercial Roofing
Rub a hand across a black rubber roof late in its life and it comes away chalky. Look along a lap and you can slide a fingernail under the edge. Look at a wall and the flashing has dropped below the line where it was sealed. Those three signs, together, describe an EPDM roof that has been in the Valley sun for a long time.
EPDM is a synthetic rubber sheet, supplied in wide rolls, that has covered flat commercial roofs for decades. In Edinburg, TX it works under sustained heat and tropical rain. Our work covers installing it, repairing laps and flashing, and saying clearly when an old rubber roof has stopped being worth repairing. The inspection starts at the lap that lifted and follows the water back from there.
Wide rolls mean few seams, and the material stays supple through temperature swings. It shrugs off ozone and ordinary weathering, tolerates normal impacts, and its repairs bond cold, without a welder, which is practical on a roof where electricity or open flame is awkward.
Trouble gathers at joints and edges. Rubber cannot be welded, so every lap and every flashing depends on adhesive or tape. That makes workmanship at installation matter more here than in any heat-welded system. It also means any repair is only as dependable as the surface prep behind it, so we log what was cleaned and primed. Oils and grease swell it, tools and boots puncture it, and a black surface soaks up Valley sun, so it runs hotter than a white sheet and ages from the top down: chalking, shrinking, stiffening. Knowing those weak points tells us where to look first.
Old laps were made with liquid contact cement, newer ones with factory splice tape. Either one holds when the sheet is clean, dry and rolled firmly. Either one lets go when grit or moisture sat in the joint during installation, or when the sheet shrinks and pulls on it. A failing lap starts with a small lift at the edge, gathers dirt, and widens with every hot day and every downpour.
We run a hand along every lap and mark where the bond is gone. If the lift is fresh and the insulation is dry, the lap is cleaned, primed and re-taped. If water has already soaked the board below, the repair goes deeper. Standing water at a lap is the commonest reason an otherwise good seam fails, so a seam failure repair treats the lap and the pond beside it together.
Over the weather service's heat-safety months, May to October, Valley roof surfaces take sustained heat and solar exposure. A black sheet absorbs it. The rubber grows, flashing adhesive softens, and the top layer slowly chalks. Damage runs worst beside equipment and along sun-facing walls, where reflected heat adds to the load.
Where the sheet is sound, a reflective acrylic coating can lower surface temperature, provided laps are re-taped and the surface is washed first. White EPDM exists for new roofs. A heat and UV damage repair is usually needed where the sheet has shrunk from a wall or the top of a flashing has lost its seal. We measure the pull at several walls, because a sun-facing wall often shows the worst of it and the shaded ones show how much is age and how much is exposure. Photographs of each wall go into the roof record with the measurements.
Three ways. Fully adhered roofs are glued to insulation or cover board and lie flat. Mechanically attached roofs are fastened along the seams with plates and screws. Ballasted roofs are laid loose under stone or pavers, with no holes through the sheet. Tropical wind treats the three differently, as Dolly's 50-to-70-mph gusts across Hidalgo County showed, and a post-storm walk looks for loose stone, lifted edges and displaced flashing.
Ballast hides the sheet, which makes leaks harder to trace, and stone that drifts toward edges can leave bare rubber and become a hazard in a gale. A roof that qualifies for a recover may be covered by a fresh sheet, though only once an infrared moisture survey shows the insulation is dry.
NWS records show large hail over the metro in spring 2012, though the service treats such hail as unusual for the Valley. Rubber absorbs small impacts well, but a stone can bruise the sheet, crack it against a hard substrate or crush insulation beneath. Hanna added its own ponding and debris in July 2020, when wind and flooding hit Edinburg.
After severe weather we look for bruises, punctures and displaced ballast and check drains for debris. The hail damage repair record shows where the sheet was struck. A lifted lap, a worn flashing and an impact mark are written up separately, each with a photograph, so an owner or insurer can see them in context. We do not credit every defect to a storm.
Flashing gets the closest look after any storm. Rubber flashing is glued up the wall and capped with a termination bar and sealant, and wind-driven rain finds the gap where sealant has dried or the bar has loosened. We press along the bar, probe the sealant and look for water tracks on the wall face, then re-bond and reseal what has gone. A wall that keeps leaking after a reseal usually points to shrinkage, and the report says whether the flashing has enough sheet left to be re-tied or the wall needs a new strip.
The city names Closner Boulevard and University Drive as the main thoroughfares of its Downtown District and gives a committee a redevelopment role there. A commercial building in a district like that may carry EPDM, and a renovation is the natural moment to decide among keeping the rubber, recovering it or replacing it. Edinburg's adopted 2018 IBC and IECC bear on downtown replacement and energy-upgrade work.
For owners in Downtown Edinburg, Edinburg and Alamo, we begin with the sheet that is there and use TPO or another single-ply as the yardstick. The report lists laps lifted, flashings pulled, moisture found and the repair boundary we recommend.
At times. A sound, dry, clean sheet can take a compatible coating that extends its life and cools its surface. Adhesion and moisture tests come first, since a coating over wet insulation hides the trouble.
Grit or damp at installation, shrinkage stress and standing water at the joint cause most of it. The face can look sound while the glue underneath has let go.
Yes, more than a light surface: it absorbs heat, which raises cooling cost and speeds aging. White EPDM is available, and a reflective coating is an option where the load matters.
Even stone cover, open drains and a periodic look at the sheet under the stone. Stone piling at drains or sliding to the edges is a signal to act before the next storm.
If soaked insulation extends beyond the patch, or the whole sheet has gone stiff and shrunken, patching only delays things.