Skylight Leak Repair in Tampa, FL Skylights Flashed, Not Caulked

Sealant is not a flashing method

The single most common Tampa skylight repair we see undone later is a bead of mastic run around a curb. It works for a season. The reason it fails is structural rather than chemical: glass, aluminum, wood curb and tile all move at different rates under a roof deck that can run past 150 degrees under dark tile on a summer afternoon, and a rigid sealant line across four dissimilar materials is being asked to absorb all of that movement. Engineered flashing kits exist for tile roofs specifically and are built to give three layers of water protection without field-fabricated metal or reliance on sealants. If a previous repair was a tube of caulk, the skylight has not actually been flashed. The wider set of these repairs is on our services page.

Deck-mount and curb-mount leak differently

Deck-mount units fasten directly to the roof deck and rely on peel-and-stick underlayment plus an engineered flashing kit, so their failures are almost always at the membrane tie-in or at a lap turned the wrong way. Curb-mount units sit on a built-up curb, so their failures cluster at the curb-to-deck joint, at the counterflashing that laps down the curb, and at the head, where water arriving from upslope has to be diverted around the unit. Knowing which type you have tells you where to open the roof, which is worth more than any amount of hose testing from below.

The pressure numbers explain the mystery leaks

The Florida Hurricane Retrofit Guide reports that wind pressure at 100 miles per hour drives water about three and a half inches up through any crack or opening on a roof, rising to roughly six inches at 130 and eight inches at 150. A skylight head flashing with two inches of upstand is therefore compliant with nothing in particular and open in a squall. That is also why a skylight can pass a garden hose test in the morning and leak that afternoon in a thunderstorm with wind behind it: the hose only reproduces gravity.

Penetration fasteners are the ones that corrode

The Florida Building Commission's survey of roofing professionals found penetration fasteners reported as usually or always corroded by 23.8 percent of respondents, higher than the 16 percent reported for tile fasteners in the open field. Skylights concentrate every risk factor in that finding: many fasteners, mixed metals between frame, flashing and deck, and a detail that stays damp longer than the surrounding tile. Within roughly ten miles of a Florida coast, 57.8 percent of the same respondents saw corrosion usually or always, against 17.3 percent inland.

If the unit is being replaced, the code has requirements

Replacing a skylight rather than reflashing it brings the glazing and energy rules with it. Florida's residential energy provisions require a solar heat gain coefficient of .30 or lower for skylights, and the requirement applies to replacement fenestration. Glazing has its own rule: laminated glass with a minimum 0.015 inch polyvinyl butyral interlayer is permitted for panes of sixteen square feet or less whose highest point is not more than twelve feet above a walking surface, with a thicker 0.30 inch interlayer required for larger or higher installations, and a safety screen requirement where any part of the unit sits more than twelve feet above the floor. Because Tampa sits in the windborne debris region, whether the replacement has to be impact rated is a question to settle before ordering, not after.

What the visit looks like and how it prices

Diagnosis starts inside, noting whether water appears at the head, the sill or a corner of the shaft, and whether it runs only in wind-driven rain. On the roof, tile comes off above and beside the unit, the flashing is exposed and read lap by lap, and the underlayment around the curb is checked for the darkened, brittle condition that means it has been wet for seasons. Repair means replacing failed flashing components with an engineered kit or properly formed metal, tying self-adhering membrane into sound underlayment with laps running downslope, and resetting tile with a breakage allowance. Cost follows unit size, mount type, roof pitch and height, how much membrane must be renewed, and whether the glass unit itself is being replaced. Where the opened area grows past 500 square feet inside the city, the permit and the dry-in inspection before tile is reset join the schedule. Related: roof flashing repair for the same craft at walls and vents, and roof underlayment replacement when the membrane around the curb turns out to be the real finding.