Commercial Skylight Repair

Skylights are penetrations. They are subject to the same flashing failures as every other penetration - except the failure consequences are larger because the glazing, the curb, and the flashing are all potential water entry points simultaneously.

Commercial skylights on Atlanta flat and low-slope roofs fail at three distinct locations: the flashing at the curb-to-membrane transition, the glazing seal at the frame-to-curb connection, and the glazing unit itself. Each failure mode requires a different repair approach, and confusing them produces repeat leak calls - patch the flashing when the glazing seal is the problem, and the leak continues from the same skylight. We diagnose before we propose a repair.

Atlanta's climate puts skylights under specific stress. The urban heat island in Midtown and Downtown Atlanta drives rooftop surface temperatures above 140°F in July, which cycles acrylic and polycarbonate glazing through thermal expansion and contraction ranges that exceed what many glazing compounds are designed to handle over time. The region's severe thunderstorm pattern produces high-volume, high-velocity rainfall that tests every detail at a skylight's perimeter. And the UV intensity at Atlanta's latitude accelerates the degradation of acrylic glazing - clarity reduction, crazing, and brittleness typically appear within 15 to 20 years on original acrylic dome skylights.

Older skylights on Atlanta commercial buildings - particularly the acrylic dome units common on 1980s and 1990s retail, warehouse, and industrial buildings in Cobb County, Gwinnett, and the suburban office corridors - are frequently at or past their glazing service life. A skylight with crazed or significantly yellowed acrylic is not just an aesthetic issue: the degraded acrylic is structurally compromised and no longer provides impact resistance against hail. We assess glazing condition as part of every skylight repair call and document it in writing.

Curb flashing failure: The curb flashing is the waterproofing membrane that transitions from the roof surface up the skylight curb to below the glazing frame. On Atlanta commercial buildings, this is typically modified bitumen flashing on older roofs and single-ply detail flashing on newer installations. Curb flashing fails at the same locations as other base flashings - at the top termination, at curb corners, and at any point where building movement or thermal cycling has stressed the flashing-to-curb bond. Repair: cut back failed flashing to sound substrate, install new flashing in the system-compatible material, integrate with counter-flashing at the glazing frame.

Glazing frame seal failure: The seal between the glazing unit and the curb frame - typically a compression gasket on quality commercial skylights or a sealant bead on lower-specification units - degrades over time. In Atlanta's thermal cycling environment, compression gaskets lose their compression set and sealant beads crack as the acrylic or polycarbonate glazing moves against the frame over thousands of thermal cycles. Repair: replace the glazing gasket or re-seal the frame joint with a UV-resistant, elastomeric sealant compatible with both the frame material and the glazing material - different products are required for aluminum frames versus thermally broken frames versus PVC frames.

Glazing unit failure: Acrylic dome skylights on older Atlanta buildings develop crazing (surface microcrack networks), structural brittleness, and in some cases delamination of double-dome units where the two acrylic layers separate. Crazed acrylic is no longer weathertight - fine cracks allow water infiltration through the glazing itself, not just at the frame. Repair: glazing unit replacement, which involves removing the existing acrylic dome, cleaning the frame, and installing a new polycarbonate (preferred) or acrylic replacement dome of matching dimensions.