Built-Up RoofingCommercial Roofing

Built-Up Roofing has been the backbone of Tacoma's commercial building stock for more than a century, and we still see original BUR assemblies holding on in Downtown Tacoma loft conversions, Pacific Avenue storefronts, and the older warehouse corridors along the Thea Foss Waterway. A properly maintained BUR system — multiple plies of reinforced felt mopped with hot asphalt, topped with gravel or a mineral cap sheet — remains one of the most redundant waterproofing assemblies available. Redundancy matters in a city that receives 42 inches of rain annually, with November alone delivering more than seven inches in sustained, low-intensity events that probe every seam and blister.

The practical challenge with BUR in Tacoma is drainage. Gravel-surfaced systems are particularly prone to drain sump blockage when wind-blown debris and fallen leaves — common from the mature street trees along Stadium District and Proctor District commercial blocks — compact against the drain screen. That standing water, sitting on a roof that was already marginally sloped to begin with, is the single biggest accelerator of BUR failure in this region. We inspect drain sumps and clear gravel from them before the November rain season as a matter of routine on every BUR building we service.

Blistering is the other common BUR defect we find on Tacoma's older industrial stock. Interply moisture trapped during original installation expands and contracts with the region's moderate temperature swings — Pacific Northwest roofs rarely see above 90°F, but they cycle through freezing temperatures on 21 or more days per year. Over decades, those cycles grow blisters large enough to crack. When a blister ruptures during a sustained Pacific Coast rain event, water tracks laterally between plies before it ever finds a drain, making the leak source difficult to trace without infrared scanning.

We use infrared moisture surveys on BUR buildings before any repair or recover decision. The survey tells us whether the insulation below the membrane is wet, how widespread the saturation is, and whether a targeted repair program can extend roof life or whether a full replacement is the responsible recommendation. For owners of buildings in the Tacoma Dome District or along the Sixth Avenue Business District who are weighing a re-cover against a tear-off, that data makes the conversation factual rather than speculative.

Historic masonry buildings — the brick warehouses near Old Town Tacoma and the mid-century commercial blocks on Pacific Avenue — often have BUR that terminates at masonry parapets. The base flashing at that wall-to-roof transition deteriorates faster than the field membrane because it takes direct wind-driven rain and thermal movement simultaneously. Re-flashing the base without disturbing the masonry requires careful sequencing and, on buildings with any historic character, coordination with the property owner on appropriate materials and finishes.

Port of Tacoma logistics buildings and Frederickson Industrial Center warehouses built in the 1960s through 1980s frequently have multi-ply BUR over steel deck. The challenge on these large-footprint buildings is the roof-to-wall edge condition: gravel stops and metal edge flashings corrode in Tacoma's marine-influenced air at the building perimeter. Salt-laden moisture carried inland from Commencement Bay and the Tideflats accelerates galvanic corrosion at steel fasteners and aluminum edge metal — we see pinhole rust-throughs in gravel-stop flanges on Tideflats buildings that are half the age of similar buildings in Eastern Washington.

When BUR replacement is warranted, we assess whether the existing steel deck is sound, what the insulation R-value needs to be to meet current Washington State Energy Code, and whether the drainage pattern can be maintained or improved. On occupied industrial buildings with dock operations running continuously — a reality for many Port-adjacent facilities — phasing the tear-off and replacement over nights or weekends keeps operations intact while we work through the field in sections.

We carry the full inventory of mopping asphalt, fiberglass-reinforced base sheets, and cap sheets to execute traditional hot-applied BUR when that is the right system for the project. On buildings where torch-applied modified bitumen is more practical than hot kettles, we can transition the specification accordingly. Our goal is the right system for the building and the owner's long-term hold period — not a default specification driven by what is easiest to mobilize.