Commercial Roofing
A loading dock that took water from the street after a tropical storm sends a facility director looking at the wrong thing. The roof is two stories up and dry in the obvious places, yet the stain in the break room points to a drain that never emptied, a scupper that spilled against a wall or a flashing that let rain run behind it. After Hurricane Hanna in July 2020, the National Weather Service reported wind, street flooding and shingle loss from a roof in Edinburg, TX, which is a good picture of how a storm splits its damage between the ground, the drainage and the roof edge.
I read a hurricane-damaged roof by asking where the water had nowhere to go, then working back to the detail that failed.
Wind-driven rain does not fall straight. It strikes a parapet wall sideways, climbs the face of a curb and finds the top of a counterflashing that was dry in an ordinary shower. The result is a leak with no hole in the field of the roof, and a ceiling stain that sits below a wall instead of below a seam. I compare the interior stain with the roof plan, mark the matching wall and trace the water up the face until I reach the termination, the sealant joint or the loose fastener that admitted it.
If the same stain follows every storm from one direction, the entry is on the windward side of a wall. Photographs taken from the roof surface and from the interior ceiling side let the owner see the same path I am following.
The Valley's flat roofs rely on drains, scuppers and overflow openings to move a great deal of water in a short time, and a tropical system tests every one. Leaves, grit and torn membrane scraps pack into a drain bowl, a scupper box fills with silt, and an overflow opening that is blocked behaves as if the roof had none. I clear each opening, check that the sump slopes toward it and look for stains that show where water sat after the rain had stopped. Where a bowl is cracked or a sump is flat, the repair is a matter of roof drains and scuppers rebuilt to drain.
The National Weather Service lists flood preparedness as a year-round concern for the Rio Grande Valley, so I treat standing water on a roof as a drainage finding first and a membrane finding second. A sheet that holds water after a storm ages faster at the low point, which is the condition behind ponding water roof repair.
The quiet damage is at the perimeter and around anything that stands up. Edge metal that shifted a quarter inch leaves a gap that is invisible from the ground. A cap flashing that flexed in the gusts can have a cracked sealant joint, and a pipe boot may have pulled away from its collar. Gusts of 50 to 70 mph from Dolly did minor damage in Pharr, and the forecasters' advice after wind like that is to look at roof edges, flashings and rooftop equipment before the next band of rain.
I add debris to the list. A sheet scarred by a flying branch or a loose panel tells me which way the wind came from, and the details downwind of it get a second look.
When another system is forecast, the order of work follows the risk of water entry. I start at the roof edges and openings that could take in the most water fastest: failed terminations, open seams, missing caps and damaged penetrations. Each one gets a photograph and a temporary seal rated for the forecast, and the temporary work is labeled in the record. Then I move to the field of the roof, where an infrared moisture survey maps wet insulation once the surface has dried.
That sequence keeps the first visit short enough to be useful. A complete survey comes after the building is safe from the next rain, not instead of protecting it.
A permanent repair has to end in sound, dry, well attached material. After a hurricane, that edge is often farther than the visible damage, because wind loosens fasteners and rain wets the insulation under a sheet that looks fine. If the cores show dry material beyond a lifted section, the repair stays local. If the moisture reaches a seam line or a drain sump, the repair extends to the next natural break in the roof, such as a wall, a curb or a drainage divide.
I write the repair boundary into the scope, mark it on a roof plan and photograph the dry test areas that support it. The same plan lists temporary work separately, so an owner can see what is finished and what still protects the building for now.
Tropical readiness covers June through October and overlaps most of the Valley's heat season, so the roof is under sun and wind load at once. Before June, I look at the parts that wind tests first: edge securement, loose flashing, sealant that has aged and equipment that is not firmly fastened to its curb. A preventive roof maintenance visit before the season is the right time to reseal and re-fasten, because the same visit after a storm is spent on emergency items.
Aging flashing deserves its own review. A termination that has hardened in the sun will open in a gust that would not have bothered it new, and that wear is what flashing failure repair addresses.
We sequence the repair around the forecast. Emergency response runs all day and all week, so the first call can bring temporary protection to the failed edge, drain or flashing the same day. Permanent repairs follow in the order that protects the most interior space first, with deliveries, tenants and operating hours worked into the schedule. A retail center and a distribution building need different plans because their roof access, loading and noise limits are different, and the phasing says so in writing.
Owners with buildings in Pharr, which felt Dolly's gusts, and McAllen, where Hanna flooded South 23rd Street, can run one inspection format across all of them, so the storm record is comparable from roof to roof. The emergency roof repair call is where that plan starts.
It should, when wind was strong enough to move equipment or loosen metal. A lifted edge and a cracked sealant joint often show nothing for weeks, and the first leak then arrives during a later rain. A walk within a few days records the condition while the cause is still clear.
Water that is driven sideways does not need a clogged drain. It climbs a wall face, passes a loose termination and enters behind the flashing, then follows the deck to a ceiling some distance away. Tracing the stain back to the wall is the first check.
Sealing open terminations, covering missing caps, securing loose edge metal and clearing blocked drains. Each is photographed and labeled as temporary, so the permanent scope can replace it without confusion about what was done.
Not by itself. Water that remains for days usually points to a drain, a slope problem or a clogged scupper first. The membrane is judged by whether it is cracked, split or unbonded at the low point, and by what the moisture survey shows underneath.
It can, if the repair adds new material to an old sheet. Adhesives and seams behave differently when a roof is heated by a Valley summer, so work during May through October is timed for the cooler hours, and each new seam gets a probe test before the crew leaves.