Commercial Roofing
Water that finds a way into a hangar usually lands on something expensive: an aircraft, a tool cart, a parts cage or a floor where a mechanic has to stand. A hangar has a very large open interior under a long-span roof, and the first roof condition I check on an aviation building in Edinburg, TX is the head of the big door, where the roof edge meets the opening that is the widest and most exposed detail on the building.
The city operates a civil airport on the north edge of Edinburg along I-69C/US 281, covering 1,080 acres and supporting general aviation, flight training, medevac, charter operations, customs, and law enforcement and military aviation flights. Buildings that serve that kind of activity range from small T-hangars to large maintenance hangars, shop buildings and office wings, and each has a different roof. The common thread is that a leak has a high price and a repair has to be done around aircraft schedules.
Most hangar leaks start at three places, and the interior stain rarely sits under any of them. The first is the door header, where a large opening interrupts the roof edge and the wall, and a flashing or a gutter must carry a lot of water off a long run. The second is the panel or membrane seam, which carries thermal movement along its full length. The third is a penetration: a fire suppression pipe, a light, a vent or an exhaust stack that rises through the roof.
On a metal hangar, fasteners back out as panels expand and contract, washers harden and sealant at laps cracks. On a membrane hangar, seams open at wall terminations and around penetrations. We trace the leak from the interior stain to the nearest of these, and we walk the whole run because a defect at one rafter bay tends to repeat at the next. A commercial roof leak repair aimed at the pattern is more durable than a series of patches.
The National Weather Service in Brownsville puts the Rio Grande Valley's heat-safety season at May through October. A long metal roof with no occupied space under it can swing widely in temperature during a day, and the result is fastener movement and sealant fatigue at every lap. Dark surfaces also drive up the heat inside a hangar where technicians are working, so a reflective finish can make the interior more comfortable.
Wind is the other load. Readiness for hurricanes in the Rio Grande Valley spans June through October, and Hurricane Dolly pushed 50-to-70-mph gusts across populated Hidalgo County, with minor damage in places such as Edinburg, Pharr and McAllen. A hangar's large span, high eave and big door opening make edge securement and fastener condition especially important, because wind pressure on a roof is highest at the corners and edges. After a tropical event we look at ridge and eave metal, rake trim, door header flashing and rooftop equipment, using a wind damage repair checklist and photographs.
We begin at the edges because that is where wind and water act first. Then we work inward along each run, noting panel laps, fasteners, seams and any past repairs.
Where access over aircraft is limited, a drone roof inspection shows the roof without walking above equipment or planes. The photo record and moisture readings then support a repair plan the operator can schedule against flight and maintenance activity. A maintenance hangar with a shop wing shares its detailing with manufacturing plant roofing, and a storage hangar behaves like warehouse roofing with a much larger door.
A hangar is rarely empty, and a roof crew above a parked aircraft has to protect it. We coordinate with the hangar manager on the dates the aircraft will be out, plan to cover or move equipment that must stay, and agree on where lifts, materials and debris will be staged outside the working area. Ground crews and fuel operations get clear access routes, and the work area is fenced away from taxi and tow paths.
On an airport property, the airport authority may set rules for who can work on the apron side and when. We follow those rules and plan the roof sequence in sections, so one bay is dried in before the next opens. A reroof while the building stays in use depends on that discipline, and the dry-in at the end of each day is checked and photographed. Debris is netted and swept so nothing blows onto the apron, where loose material is a hazard to aircraft and ground equipment.
A repair works when the panels are sound and the leaks come from specific fasteners or laps. A metal roof retrofit can make sense when the structure is sound and the old panels are beyond repair but the building cannot afford a full tear-off. A replacement is the answer for roofs with corroded panels, saturated insulation or leaks across many bays.
Cost moves with the length and width of the span, the height of the eaves, the number of penetrations, the access equipment needed and the aircraft schedule. The city holds the 2018 International Building Code and 2018 International Energy Conservation Code on its adopted list, and a hangar replacement is scoped to meet them. Buildings near the US 281 and I-69C corridor see the same weather as the rest of the city, and a lender or insurer will ask for the same documentation.
It needs fasteners that match the panel, the purlin spacing and the wind exposure, with sealing washers at every penetration. At edges and corners the pattern is tighter. We check the existing pattern against what the panel maker's instructions call for, and we replace stripped fasteners with ones that grip a sound substrate.
Often yes, if the work is phased by bay and the aircraft below are covered or moved for a short time. We agree on which bays are open on which days, and the dry-in at day's end keeps the interior dry. The hangar manager sets the limits, and we plan around them.
It shows panel laps, trim and penetrations from above without anyone stepping near equipment. Images taken at low angle highlight ponding and surface staining, and thermal images can show wet insulation where the roof has an insulated layer. The survey supports a decision, and a follow-up walk confirms the details.
Photograph the roof edges, door header and penetrations as soon as access is safe, note the date and the reported wind, and save any interior leak photos. Hurricane Hanna produced wind and flooding impacts in Edinburg in July 2020, and records like these are what separate storm loss from long-term wear.
They can be. The panel laps and fasteners are similar to metal, but the panel material ages in sunlight and can become brittle. We check for cracks, discoloration and loose fasteners, and if the panels are failing we replace them with new ones or with insulated metal to reduce heat and leaks.