Commercial Roofing
A dark, damp ring around the base of a rooftop unit, with algae growing along one side of the curb, is the first thing worth checking on a warehouse roof in Edinburg, TX, because the water that shows up inside often entered at a piece of equipment and not in the open field of the roof. Units, curbs, pipe stands and conduit all cut through or sit on the membrane, and every one of them has a flashing or a footing that can fail.
We start at the curb and work outward. Trace the water path from the stain back to the unit, check the flashing height and the sealant, look at the support under the frame, then decide whether the repair boundary stops at the curb or runs further across the roof.
A curb is a raised frame that holds a unit above the roof surface, and the membrane is turned up its sides and capped with counterflashing. Failures follow a pattern. The membrane at an inside corner stretches and splits. The sealant bead at the cap dries in the sun and opens. The base flashing slumps down the face of the frame. A seam crossing the base of the curb lets water run under the sheet.
Our hands go along the turned-up membrane for hollow spots, and we look at how high the flashing stands above the field and check whether water ponds on the upslope side. Flashing that only rises a few inches can be overrun by a heavy rain, and tropical storms are part of the Valley's pattern. When a curb needs more than a patch, we cut back to sound membrane and rebuild the base flashing, tied into dry material, and the flashing failure repair carries the new work onto clean roof.
Cooling equipment runs for months on end here, since May to October counts as heat-safety season to the weather service, and condensate lines keep dripping through all of it. A drain pipe that discharges onto the membrane leaves a wet stain, grows algae, and in time wears a path through the surface. A pipe that sags between supports collects water at its low point and drips on one spot.
We trace each condensate line to its end. The fix may be a longer run to a drain, a splash pad under the discharge, or a re-pitched pipe with a support every few feet. Rooftop pipe supports should lift the line clear of the membrane and spread the load; a loose block sliding on the surface grinds a hole in the sheet. If the roof under a discharge point has already softened, a membrane puncture repair and a protection pad belong in the same visit.
Hurricane Dolly's gusts, 50 to 70 mph in populated Hidalgo County with minor damage in Edinburg itself, led the weather service to recommend a look at roof edges, flashings and rooftop equipment after tropical wind. A unit that is loosely strapped to its curb, or a curb that is lightly fastened to the deck, is a candidate to shift in a storm and tear the flashing as it moves.
After a tropical event we walk the equipment first. We look for displaced panels, loose straps, bent supports, cracked sealant and curbs that have shifted. We check the fasteners that hold each curb to the deck and the straps or clips that hold each unit to the curb, and the mechanical contractor handles any adjustment to the unit itself. Where a curb has moved, the flashing is replaced and not patched, since a shifted frame will keep working the same joint. A hurricane damage repair record notes what moved and what held.
Equipment that rests on rails, sleepers or pads puts its weight into the roof assembly. Under a rail, insulation can compress, the deck can deflect and the membrane can be pinched against a hard edge. The tilt that results changes the flashing and the way water leaves the unit. If wet insulation sits under a support, the support will settle further, so the repair begins with a moisture check.
We probe the roof under suspect supports, look for dents in the surface and check whether the unit is level. When the support is sound but the protection beneath is worn, we lift the equipment with the mechanical crew, replace the protection layer and reset the frame on a clean area. A moisture survey before a changeout shows which curbs sit over dry roof and which sit over wet insulation, and that finding sets the repair boundary before a crane is booked.
A changeout opens the roof. The old unit comes off, the curb stands open to the building and the weather arrives on its own schedule. Rain from the Valley's tropical season can follow a hot, calm morning in an hour, so the dry-in plan has to be set before the crane arrives: who disconnects the unit, what temporary cover is on site, how the opening is closed if the new unit arrives late and who finishes the flashing once the unit lands.
New units rarely match the old curb in footprint, weight or duct location. We check the new dimensions, adapt or replace the curb and confirm the flashing height is enough for the new frame. If the building stays occupied, a phased work plan keeps the interior protected. Scheduling the curb work with the changeout is faster and cheaper than a return visit, since the roof is already clear around the unit.
The local employment base spans healthcare, higher education, government, logistics and warehousing, with food processing and manufacturing too. Those building uses differ, but several need heavy ventilation and cooling, and that equipment sits on the roof. Road work matters for equipment jobs as well: crane and delivery access depend on the lane and lot at each site, and Schunior Avenue, Sugar Road and FM 2812 are among the Edinburg roads TxDOT shows under improvement.
For owners in Edinburg and McAllen, we map every curb and support on the roof, record the condition of each and rank the work by risk of water entry. Edinburg's adopted codes include the 2018 IBC and IECC, so a curb change that touches insulation or the roof assembly is checked against them. The ranked list becomes the repair plan, with the highest-risk curbs first.
The deciding factor is where the water enters. A split cap or dried sealant bead can be reached with the unit sitting there. Failed base flashing, a damp curb interior or a shifted frame needs the unit lifted so the flashing can run down to sound membrane.
Use the larger of two numbers: the manufacturer's minimum flashing height and the depth of water the roof can hold beside the curb. In a heavy tropical rain, the second number can be the bigger one.
A path that ends over a drain, a pad or a gutter, with a support at regular intervals so the pipe does not sag. Where it ends on bare membrane, the wear shows up first as a stain and later as a hole.
Mechanical and electrical trades own that part. The curb, flashing and dry-in are ours, and we sequence the work with theirs so the opening never sits unprotected overnight.
They add a check. After a significant wind event we walk every unit, curb and pipe support, look for movement, and photograph anything that shifted, before the next rain finds the opening.