Built-Up Roofing in McKinney, TX

A built-up roof is assembled on site from alternating layers of reinforcing felts, or plies, and bitumen. The bitumen is usually asphalt, applied hot, cold or by torch, and the felts are fiberglass or polyester. Three or four plies are common, topped with a surfacing: gravel embedded in a flood coat, a granulated cap sheet or a reflective coating. The layers work together as a redundant waterproof barrier, so a single weak spot is unlikely to open the whole roof.

That redundancy is also why built-up roofs last as long as they do, and why they are heavy. A roof with a gravel surface carries stone that protects the bitumen from sun and hail, but it hides what is underneath. During inspection we sweep sample areas clear to see the surface, probe blisters and look at the felts at edges and flashings, where the layers are visible.

The common built-up defects are easy to name. Blisters are pockets of trapped air or moisture between plies. Alligatoring is the crazed cracking of the asphalt surface under sun. Ridges along insulation joints show where the deck or insulation moved. Exposed felts appear where gravel has been scoured off, usually near drains, edges and the paths water takes during a storm. Flashings fail where the base flashing separates from a wall or curb.

Each defect carries a different decision. A small blister on a dry roof can be cut, dried and patched. A field of blisters suggests trapped moisture and calls for testing. Widespread alligatoring and exposed felts mean the surface has lost its protection, and recoating may serve if the plies below are sound. We photograph each condition against a work zone and probe before we write the repair edge. Where blisters are cut open, we note the moisture level and the number of plies exposed, since that count tells us how much of the original system is still working.

Hail belongs to spring in the Metroplex, which the Weather Service marks as the peak of severe weather. A gravel-surfaced built-up roof is among the more impact-tolerant surfaces because the stone and the thick plies spread the blow, though large stones can still fracture the felts or displace gravel. Our post-storm inspection looks for bruised surfacing, scoured areas, split plies and wet insulation. Regional storm reports alone say nothing about one building.

Summer heat adds its own load. Dallas-Fort Worth summer normals sit in the mid-90s, and asphalt softens in that range, which is why foot traffic across a hot roof can leave marks and why hot-work scheduling matters. Annual precipitation of about 37 inches, with May the wettest of the normals at 4.78, means drains work hardest as the storm season peaks. Clean drains and intact gravel guards are the first defense.

Hot asphalt arrives in a kettle on the ground or on the roof, and the hose, the mop or the mechanical spreader carries it to the deck. The kettle needs a stable location, a fire extinguisher, trained attendants and a fume path that stays away from air intakes. Some owners and insurers prohibit it above occupied space, and then cold-applied adhesives or a self-adhered sheet are used. Whichever method applies, the facility director signs off on the sequence: where the kettle sits, when loud work happens and which intakes are protected.

We map the intakes, protect them with the building engineer, and keep the work zone clear of foot traffic from the loading area. If the roof is occupied below, we stage interior protection and leak response before the first section is opened.

Choices on an aged built-up roof run from maintenance to removal. A dry, sound roof with a failing surface can take a reflective coating after repairs, which protects the bitumen and cuts surface heat. A dry roof with firm plies but blistered areas can take a recover, usually a single-ply sheet over a cover board. A wet roof needs removal of the affected plies and insulation. Layering a new roof over wet insulation only holds the water in place.

Where a building is being re-roofed with a different system, an old built-up roof may go away entirely, including its gravel, and the disposal plan becomes a cost line. Permit review brings in the city's adopted building and energy codes and their local amendments, and we confirm what applies before pricing.

Insulation and cover board decide the next phase. A recover over a built-up roof needs a board that bridges the old surface and takes fasteners or adhesive, and roof insulation and cover board choices set the fire rating, the thermal value and the finished height at doors and curbs. Cost follows the same list: wet insulation, drain count, parapet height, disposal weight and the production window. Gravel adds disposal weight on every tear-off, so a roof that can be recoated and kept avoids that cost, while one that must be hauled away carries it in full.

Gravel, felts and bitumen arrive heavy, and tear-off debris leaves heavy. The city describes office and industrial parks throughout McKinney and retail development districts along its main routes, so staging space differs a great deal from one site to the next. We set the lift plan, the staging area and the debris path early. Near the Custer Road and US 380 District or the North US 75 District, truck approach and parking limits are confirmed on site. A preventive roof maintenance visit before spring clears gravel from drains and checks flashings, and owners comparing options can look at modified bitumen roofing as the factory-made relative of this system.