Service
Commercial Skylight Repair in Cincinnati, OH
Commercial skylights on Cincinnati flat roofs fail at their curb flashings long before they fail at their glazing. Freeze-thaw cycling opens the flashing laps at the curb base, ice backs water under the counterflashing, and the leak appears at ceiling level — often blamed on the glazing when the actual source is 18 inches away at the curb perimeter.
Cincinnati commercial buildings with flat roof skylights — warehouse daylight strips, office atrium units, and retail feature skylights — face a consistent set of failure modes driven by Ohio Valley climate. The curb flashing that integrates the skylight into the roofing membrane is the most common failure point. TPO or EPDM base flashing that turns up the skylight curb and terminates at the counterflashing must accommodate the thermal cycling range from Cincinnati's summer roof temperatures (140 to 155°F surface) down to January lows below 0°F. After 10 to 15 years of that cycling, flashing laps fatigue.
Skylight glazing failure is less common but does occur on older polycarbonate units — yellowing, crazing, and delamination of multi-wall polycarbonate panels that have been exposed to Cincinnati's high-UV summer loading for 20 or more years. Glass-glazed skylights are more durable against UV but are vulnerable to the hail events that track across Hamilton County three to eight times per year.
We assess and repair commercial skylights as part of roof inspection scopes and as standalone service calls. Our work covers the curb flashing, the counterflashing, the curb substrate condition, and the glazing — the full assembly, not just the piece that is obviously wet.
Skylight Failure Points on Cincinnati Commercial Roofs
Curb base flashing failure: The most common Cincinnati commercial skylight leak source. TPO or EPDM base flashing that turns up from the roof field to the top of the curb frame fatigues at the inside corner and at the top-of-curb termination. Ice backing up under the membrane during Cincinnati ice storms concentrates at skylight curbs — the elevated curb creates a dam where ice accumulates and backs water under laps that may otherwise hold.
Counterflashing and cap flashing failure: Metal counterflashing that laps down over the base flashing to keep water out of the curb assembly requires adequate lap and sealant that holds through Ohio Valley UV and thermal cycling. Counterflashing that has lost its sealant seal or that has pulled away from the curb frame allows direct water entry at the skylight perimeter.
Curb frame condition: Skylight curb frames on Cincinnati commercial buildings — wood framing on older structures, steel or aluminum on newer — deteriorate from moisture exposure at the base of the curb where flashing laps collect water. Rotted wood curb framing cannot hold the counterflashing securely and requires rebuild before new flashing will stay watertight. Steel frames can rust at welds and fastener penetrations.
Glazing condition: We assess polycarbonate glazing for UV degradation — yellowing and loss of light transmission — and structural delamination of multi-wall panels. Glass glazing is assessed for seal failure at glazing compound joints (the source of condensation between panes in double-glazed units) and for hail impact fractures. Glazing replacement is specified separately from flashing repair when the glazing is the primary concern.
Our Skylight Repair Scope
Curb flashing replacement: New TPO or EPDM base flashing from the roof field up the curb face and over the curb top, with properly constructed inside corner pieces at each curb corner. Corner geometry is cut and welded (TPO) or adhered (EPDM) per manufacturer detail — factory-preformed corners are used where the curb geometry allows, field-fabricated corners where it does not. New termination bar at the top of the curb with compatible sealant.
Counterflashing repair or replacement: Reglet counterflashing for masonry-surrounded skylights, surface-mounted counterflashing replaced with sealant reset for metal-frame skylights. Counterflashing that has lost dimensional integrity — bent, pulled, or corroded — is replaced rather than sealed and hoped. We photograph the completed counterflashing condition against the manufacturer's flashing detail at closeout.
Curb substrate repair: Rotted wood curb framing rebuilt with pressure-treated lumber. Steel curb frame rust stabilization and primer coat at affected welds. We do not install new flashing over failed substrate — new flashing on a rotted curb fails at the fasteners within 12 to 24 months.
Glazing replacement: Polycarbonate panel replacement with current UV-stabilized material, double-wall or triple-wall depending on the unit specification. Glass panel replacement with matching glazing specification. We coordinate glazing replacement with the skylight manufacturer where the unit is still in production, and source compatible replacement glazing from commercial glazing suppliers for older units.
Condensation vs. Infiltration at Cincinnati Skylights
Cincinnati's Ohio River basin humidity creates condensation at commercial skylights that can be mistaken for active leaks. Condensation forms on the interior skylight frame and glazing when interior air at high humidity contacts the cold skylight surface during Cincinnati winters — visible as water droplets at the frame perimeter, sometimes with drip patterns that look like a flashing leak.
We distinguish condensation from infiltration during inspection — the pattern and timing of interior moisture is the first indicator. Condensation at Cincinnati skylights does not require flashing repair; it requires improved skylight frame thermal break or better interior humidity control. We document the distinction and do not replace flashings that are watertight.
Frequently asked questions
Can you repair skylights on occupied Cincinnati commercial buildings?
Yes. Most curb flashing repairs are performed from the rooftop with no interior access required. Glazing replacement requires interior coordination when the glazing panel must be removed from below. We schedule glazing work around the building's occupancy — early morning or after-hours for
When does a Cincinnati commercial skylight need replacement rather than repair?
Replacement is warranted when the curb frame has failed structurally, when the glazing is beyond useful life and replacement panels are not available for the unit, or when the cumulative cost of repairing a severely deteriorated unit approaches the cost of a new unit installation. We give owners both the repair cost and the replacement cost when the repair scope is significant enough that the comparison is warranted.
Does hail damage require skylight replacement?
One-inch and smaller hail typically does not damage glass-glazed commercial skylights unless the glass is already stressed. Two-inch and larger hail can fracture glass panes and crack polycarbonate panels. We inspect skylight glazing after every documented significant hail event in Hamilton County and note any glazing damage for insurance documentation.
What is the lead time for skylight glazing replacement in Cincinnati?
Standard polycarbonate replacement panels are typically available through commercial glazing suppliers within 5 to 10 business days for common sizes. Custom or non-standard glazing dimensions, or glass panels for specific skylight units, may require 3 to 6 weeks. We assess glazing availability before quoting repair timelines.
Skylight leaking or failing on a Cincinnati commercial building?
We will assess the curb flashing, counterflashing, curb substrate, and glazing condition in a single visit and produce a written repair or replacement scope.
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