Commercial Roofing
A drip over an aisle end cap is a safety problem before it is a roofing problem: a wet floor, a slipped customer and a manager hunting for a bucket in the middle of the afternoon. For a store in Edinburg, TX, the roof is the largest single surface on the property. A big-box roof is a single huge surface with a few hundred details on it: rooftop units, skylights, vents, roof hatches, drains and miles of seams.
We start by getting the store's roof drawing, then trace any leak from the sales-floor stain backward across the roof. Photographs pinned to that drawing separate sound areas from moved ones and mark the spot where one small test could settle an open question.
On a big-box roof the field is rarely the first to fail. The details are: rooftop unit curbs, skylight curbs, exhaust fans, plumbing vents, roof hatches and drains. A store may have dozens of rooftop units, and each one is serviced by technicians who walk across the membrane. Foot traffic wears paths, and service tools drop and puncture.
At the perimeter, the parapet cap and edge metal take wind load, and the entrance canopy and storefront facade have their own transitions. We check curbs and penetrations first, then drains and scuppers, then perimeter metal and the seams between. Skylights are a special case: the curb flashing and the glazing seal both age in the sun, and a leaking skylight often looks like a roof leak. A skylight and penetration flashing repair rebuilds the curb detail, and a walk pad along service routes protects the membrane.
A big-box roof deck spans long distances with few interior walls above the sales floor. Water that enters at one edge or curb can travel the length of a deck flute or along a joint, drip from a fastener and appear in the aisle forty feet away. Insulation above the ceiling holds the water and releases it over days.
We ask the store manager when and where the water appeared and what the weather was, then map the stains on the drawing and walk the roof along the line. Moisture readings or an infrared scan show how far the wet insulation extends. On a roof this large, a scan is the practical way to define the repair area. The extent decides whether a local repair is enough or whether the roof needs a wider scope. An infrared moisture survey before a replacement also keeps the scope grounded, since it shows how much insulation has to come out.
Large retail roofs are commonly single-ply membranes, such as TPO or EPDM, in mechanically attached, fully adhered or ballasted form, though built-up and metal roofs also appear. The attachment method matters at the edges, where wind load is highest. A mechanically attached roof relies on fastener spacing, and a ballasted roof relies on stone or pavers staying put.
We confirm the system from samples and records, then check the perimeter: edge metal, fasteners and the membrane termination. Tropical wind reached Hidalgo County in Dolly, and Hanna followed with wind and flooding in Edinburg in July 2020, so after a wind event we inspect edges first for lifted metal and loose fasteners. A wind damage repair record documents condition for the owner and the insurer.
A big-box roof takes in sun through the whole May-to-October heat-safety stretch the Valley's forecasters describe, and the store's air conditioning works against that heat. Hot membranes expand through the day and contract at night, and the movement concentrates at curbs, edges and seams.
Heat also ages sealants and plastics. We look for crazing, shrinkage and hardened sealant at curbs and walls, and for unit drain lines that dump condensate in one spot, which stains and wears the membrane. A cool roof installation may fit a replacement plan, since reflective surfaces lower the heat load on both the membrane and the cooling system. Repairs on heat-aged roofs need clean, flexible material to bond to, and the record marks areas where the membrane has hardened and patches will be short-term. On a roof this size, the repair list is long, so we group items by roof zone and by urgency: leaks first, then details that are likely to leak next season, then wear that can be watched. The manager receives the list with photographs and a rough order of work, which makes it easy to approve the first group and schedule the rest. Entrance canopies and the storefront facade get their own line, since a drip there reaches customers at the door before it reaches any shelf, and a gutter or scupper at the front elevation is cleared before the roof behind it is touched.
Patching is enough when moisture is limited and the membrane around each repair is sound. A reroof comes into the discussion when insulation is wet across large areas, seams fail across the field or repairs recur at a pace that outruns the budget for them.
For a store that cannot close, we compare a phased replacement, one zone at a time, with a recover where the existing roof allows. The cost drivers are layers, wet insulation, number of units to be lifted, access and the store's seasonal calendar. Retailers often want to avoid the holiday period, and hurricane season runs from June through October, so the window can be narrow. Permit questions go to the city, which works from the 2018 building and energy codes. Each phase is described with the sales-floor area below it, the protection in place and the date the next zone opens.
Customer safety comes first. We map the parking lot, entrances, garden center and loading docks with the store manager, fence the work area and place lifts, staging and dumpsters away from customer routes and fire lanes. Material deliveries are timed for early hours.
Inside, we set protection over merchandise below the work area and coordinate rooftop unit shutdowns so that departments with refrigerated goods are not left without cooling. No section stays open overnight, and covers wait on the roof for a sudden shower. We record the times for the manager and the district office. Retail owners with stores in McAllen and Edinburg can use the same record at each location. Related building types follow similar logic, as with shopping center roofing and grocery store roofing.
Usually. We work in zones, protect merchandise below, keep customer routes clear and close each section the same day.
It can be either. We check the curb flashing and the glazing seal separately to see which one lets water in.
By infrared scan, then confirmation with moisture readings or a small core. The mapped area sets the repair boundary.
Perimeter metal, flashings, rooftop units and drains, in that order. Wind lifts edges and shifts equipment before water shows inside.
Edinburg's 2018 building and energy code adoption is the starting point, and the city's building department rules on what a store reroof permit must show, including insulation values.