Fort Worth's UV exposure is among the highest in North America. Skylight glazing that was installed 15 years ago was not designed for cumulative UV load at this latitude — the glazing yellows, crazes, and loses its seal. The curb flashing below it fails for the same reasons parapet flashings fail. We rebuild both.

Commercial skylights on Fort Worth flat roofs fail at two points: the curb flashing where the skylight frame integrates with the roof membrane, and the glazing itself. Both failures are driven primarily by the same force — the ultraviolet radiation load of a North Texas installation, compounded by the thermal cycling between 160°F summer rooftop surface temperatures and the freeze events that hit Tarrant County on average three to five times per winter.

A skylight curb is the raised frame assembly that lifts the glazing unit above the roof surface so that membrane can be flashed up the curb sides. The flashing system at the curb is geometrically similar to the flashing at any rooftop equipment curb — base flashing up the curb face, cap or counter-flashing over the curb top edge, and sealant at the transition between the frame and the glazing. It is a complex geometry with multiple transitions, and each transition is a potential water entry point when the sealant and flashing materials age under UV.

We repair commercial skylights on the roofing side — curb flashing rebuild, curb cap sealant restoration, and frame-to-glazing transition repair. For glazing replacement (the light-transmitting panels themselves), we work with a specialty skylight glazing contractor as a subcontractor on projects where the glazing has failed beyond sealant restoration. We manage that coordination and deliver the finished scope to the building owner as a single project.

Curb Flashing Failure Modes and Rebuild

The most common curb flashing failure on Fort Worth commercial skylights is sealant deterioration at the counter-flashing-to-frame interface. The metal skylight frame and the metal or membrane counter-flashing expand and contract at different rates (the frame follows the glazing temperature; the counter-flashing follows the roof membrane temperature), and the sealant joint between them absorbs that differential movement. Fort Worth's 80°F swing between winter and summer rooftop temperatures produces measurable differential movement at this joint every year. Polyurethane sealants typically survive 5–7 years at this joint; silicone sealants survive 10–12 years. When the sealant fails, water enters at the frame perimeter.

Base flashing failure at curb corners is the second common failure mode. Curb corners require membrane cuts and folds that create stress concentration points under thermal movement. On TPO and PVC systems, the corner is heat-welded with a pre-formed corner boot — when the weld fails or the boot cracks, water enters at the corner and migrates under the base flashing. On EPDM systems, corners are formed with pressure-sensitive flashing tape and contact-adhesive bonding, which is vulnerable to delamination in sustained water contact. We rebuild curb corners with the appropriate manufacturer flashing detail for the membrane system — not a generic corner patch.

Curb cap / counter-flashing uplift: Fort Worth's wind exposure — the city sits in an open terrain corridor that accelerates southwest winds during storm fronts — creates uplift pressure at curb cap edges. Curb caps that are face-fastened without adequate sealant at the fastener penetrations are particularly vulnerable. We inspect fastener pattern and sealant condition at every skylight curb as part of our standard inspection protocol.

UV-Degraded Glazing — Assessment and Replacement

Commercial skylight glazing is typically acrylic, polycarbonate, or glass. Acrylic (polymethyl methacrylate) and polycarbonate degrade under UV exposure, becoming brittle, yellowed, and less transparent over time. In Fort Worth's UV environment, acrylic domes installed without UV-stabilizer coatings show visible crazing and yellowing within 10–15 years; polycarbonate panels with UV coatings last 15–25 years depending on coating quality. Glass systems last indefinitely if the frame and gasket system maintains its seal.

Glazing assessment involves more than visual inspection. We probe glazing panel perimeter seals and gasket condition, check frame drainage channels for blockage (a blocked glazing channel creates standing water at the glazing-to-frame junction, which accelerates seal failure), and assess the structural integrity of the skylight frame itself. On older commercial skylights in Fort Worth's Near Southside warehouse district and the Camp Bowie commercial corridor — many of which were installed in the 1980s and 1990s — the frame may have corroded at welded joints or at fastener locations where dissimilar metals created galvanic corrosion.

Glazing replacement is a specialty scope. We subcontract glazing panel fabrication and installation to skylight specialists and manage the project coordination, including the roofing membrane integration at the curb that the glazing installer does not perform. The roofing scope (curb flashing rebuild) and the glazing scope (panel replacement) are sequenced so the curb is ready for the new glazing before the panel arrives on site — which eliminates the window of open-skylight exposure.

Condensation and Interior Moisture Management

Fort Worth's climate creates skylight condensation conditions in winter that building owners in drier climates do not encounter. When interior building humidity meets a cold glazing surface (during a Fort Worth freeze event, exterior temperatures can drop below 20°F within hours of a front passage), condensation forms on the interior glazing face and runs to the frame. If the frame does not have an adequate internal drainage channel to the exterior, condensation accumulates in the frame and drips to the interior — which presents as an apparent roof leak during freeze events.

Condensation leaks are diagnostically distinct from infiltration leaks: they occur during or immediately after freeze events (not rain events), they produce dripping at consistent frame locations (not random infiltration patterns), and they stop when interior temperatures equalize with exterior temperatures. We diagnose condensation leaks specifically when the symptom pattern matches and recommend the appropriate intervention — which is typically frame drainage channel clearing, supplemental interior vapor barrier, or increasing interior ventilation near the skylight rather than a roofing repair.

True infiltration through a skylight (rain entering through the curb or glazing seal) and condensation are sometimes present simultaneously — especially on Fort Worth buildings that experienced the 2021 Uri freeze event, when freeze-thaw cycles cracked both glazing seals and caused interior condensation simultaneously. We separate the two diagnoses and scope each repair correctly.

Fort Worth commercial skylight leaking or glazing degraded?

We assess the curb flashing, glazing condition, and frame integrity — and we manage the full repair scope including glazing replacement if needed.