Built-Up Roofing - Assessment, Repair, and Replacement

Atlanta's 1960s through 1980s commercial building stock is heavily weighted toward built-up roofing. We assess BUR system condition, document insulation saturation and membrane integrity, and specify repair, recover, or replacement paths based on what the data shows - not what avoids the largest capital commitment.

Built-up roofing was the dominant commercial flat-roof system in Atlanta from the 1950s through the mid-1980s. The Marietta industrial corridor, the Dobbins Air Reserve Base supplier facilities, the older warehouse and manufacturing stock along I-20 west, the 1960s and 1970s commercial buildings in College Park and East Point near Hartsfield-Jackson - most of this inventory was built on BUR systems with gravel ballast, and much of it has never been fully replaced. Some of these roofs received coal tar maintenance applications or cold-process coating patches over the decades. A few received modified bitumen recover systems in the 1990s. Most are now past any reasonable definition of serviceable life and represent active water intrusion risk.

We do not install new BUR - there is no market for new BUR construction in the Atlanta commercial sector, and the material handling, hot-mopping logistics, and cure time requirements make it economically noncompetitive against modern single-ply and modified bitumen systems. What we do is assess existing BUR systems honestly: pull cores, document moisture saturation, evaluate membrane and felts, assess gravel ballast depth and distribution, and produce a written recommendation on whether repair, recover, or replacement is the correct scope.

The honest assessment matters because BUR assessment is frequently done wrong. Contractors who want the recover or replacement project will overstate deterioration. Contractors who want to avoid the capital commitment will understate it. Our assessment protocol is the same regardless of what it produces: documented core pulls, infrared scan on larger roofs where saturation mapping warrants it, written condition rating, and a scope recommendation the owner can use to obtain competitive bids - including bids from contractors other than us if they prefer that process.

Insulation saturation from moisture infiltration: Atlanta's 53-inch annual rainfall and high summer humidity are a chronic enemy of BUR insulation. Water infiltrates through membrane cracks, alligatored bitumen, and failed flashings at parapets and penetrations. Once inside the insulation stack - typically fiberglass or perlite board on Atlanta commercial BUR - moisture does not exit in humid summer months because the ambient moisture gradient prevents drying. Core pulls on Atlanta BUR systems regularly show 30 to 50 percent saturation rates on roofs that are visually serviceable from the surface. Saturated insulation has no R-value and drives interior ceiling and wall damage well before it produces visible roof failure.

Alligatoring and oxidation of the bitumen surface: The exposed asphalt flood coat on gravel-ballasted BUR systems oxidizes over time, producing the surface-cracking pattern called alligatoring. Alligatoring does not necessarily mean the underlying felts have failed - it is a surface condition - but it does indicate the bitumen is no longer flexible enough to accommodate thermal cycling without cracking. Atlanta's 70-degree annual temperature range accelerates alligatoring on roofs with inadequate gravel coverage that do not protect the flood coat from UV exposure.

Gravel ballast displacement: Atlanta's thunderstorm cycle creates high wind uplift that displaces gravel ballast from perimeters and high-exposure zones, leaving the underlying flood coat exposed. Once the flood coat is exposed, UV and thermal cycle attack accelerates dramatically. We assess gravel coverage depth and distribution during inspection and document displacement patterns - which also serve as a proxy map of where wind uplift is highest on the specific building.