A skylight can take a hard hail strike without dripping that night. The glass may remain intact while the aluminum frame is dented, the flashing is loosened, or the seal around the glazing is damaged. Those faults can stay quiet through a light rain and show themselves during the next wind driven storm. If hail crossed your St. Louis neighborhood, the useful question is not simply whether the skylight leaks. It is whether the skylight and the roofing around it still form a reliable water shedding system.
Storm and hail
A skylight is not one part. It includes the glazing, frame, seals, curb or deck connection, and flashing woven into the roof covering. Hail and wind can affect each part differently. A proper inspection separates damage to the skylight itself from damage to the shingles and flashing around it.
Start with the glazing
Modern skylights may use glass, acrylic, or polycarbonate glazing. A crack, chip, puncture, or shattered outer pane is an obvious reason to keep water out and arrange repair promptly. Smaller marks require closer reading. A surface scuff is not the same as a fracture, and dirt can resemble impact marks from the ground.
Look from inside for a new crack, moisture between panes, or a cloudy area that does not wipe away. Moisture trapped between panes usually points to a failed insulated glass seal. It does not prove hail caused the failure, but it does mean the glazing unit is no longer performing as intended. From the roof, the inspector should photograph individual impact points and the full skylight so you can see where each mark sits.
Do not climb onto wet, frosted, or hail covered shingles to inspect it yourself. Frost can make an ordinary roof pitch difficult to stand on, and a thin white layer can hide loose granules, split shingles, and slick metal flashing. Let the roof dry before anyone calls the skylight clear.
The frame can be damaged without broken glass
Aluminum cladding around a skylight often records hail clearly. Rounded dents may show the direction and approximate size of the impacts. Dents alone do not always create an active leak. Their importance depends on location and depth. A dent near a joint, corner, glazing seal, or drainage channel deserves more attention than a shallow mark in the middle of a broad metal surface.
Wind can also shift a venting skylight or damage its operating hardware. Open and close an operable unit from inside. It should move evenly, latch fully, and sit square against its gasket. Stop if the sash binds or the handle requires unusual force. Forcing it can turn a small alignment problem into broken hardware or a seal that no longer closes.
The flashing is usually the critical inspection point
Skylight flashing directs water around the opening and back onto the shingles below. Along the sides, individual step flashing pieces should overlap in sequence with each shingle course. Head flashing protects the uphill side. Sill flashing releases water at the bottom. Some installations use a manufacturer designed flashing kit, while older units may have site formed metal.
After a storm, look for lifted shingles beside the skylight, bent flashing, exposed fasteners, torn sealant, or debris packed along the uphill edge. A branch does not have to break the glass to disturb this assembly. Wind can lift an aging shingle and break its seal directly beside the frame. Water can then travel beneath the roof covering before it reaches the ceiling.
A bead of roof cement around the frame is not a substitute for correctly lapped flashing. Sealant has useful, limited jobs, but a skylight should not depend on a thick exposed bead to keep out every rain. St. Louis heat, ultraviolet light, and freeze thaw cycles make exposed sealant shrink and crack. If the inspection finds layers of old patching, ask what is underneath before adding another layer.
A ceiling stain does not locate the opening
Water entering beside a skylight can follow the roof deck, framing, or the sides of the light shaft. The stain may appear several feet downhill from the actual entry point. Condensation can complicate the picture. Warm indoor air reaching a cold skylight can leave moisture on the glass or frame even when the roof flashing is sound.
Note when the moisture appears. Leakage during wind driven rain points toward an exterior opening or flashing detail. Moisture on cold mornings, especially around the lower edge of the glass, may indicate indoor humidity, air leakage, or insulation gaps around the shaft. Ice damming at the eave can also back water under roofing, although that water may emerge far from the eave after following the deck.
The inspection should therefore include the roof surface, the skylight exterior, and the interior shaft when accessible. Photographs of only a ceiling stain do not settle where the water entered.
What it costs
The price depends first on which component failed. Replacing a small section of disturbed flashing is different from removing and reflashing the entire skylight. Replacing an insulated glass unit is different from replacing the frame, curb, and surrounding shingles. Access also matters. A skylight high on a steep roof requires more setup than one on a low, walkable slope.
Ask for the work to be divided into named parts:
- Removal of shingles around the skylight
- Inspection of the roof deck and curb
- Replacement or reuse of the skylight
- A new flashing kit or site formed flashing
- Ice and water membrane around the opening
- Replacement shingles and underlayment
- Interior drywall, paint, or trim work, if included
- Disposal, cleanup, and permit responsibility
That list matters because a low number may cover only exposed sealant or a small patch. It may not include removing shingles to see the step flashing. Conversely, full replacement may be unnecessary when the glazing and frame are sound and the fault is confined to a repairable roofing detail.
Age changes the decision. A newer skylight with available parts may be worth reflashing. An older unit with cloudy glass, brittle gaskets, worn hardware, and no readily available flashing kit may not be a good candidate for removal and reuse. Once the surrounding shingles are lifted, reusing an aging unit can leave the homeowner paying for the same access work again when the glass seal or hardware fails.
The roof around it matters too. Three tab shingles become increasingly difficult to manipulate without breakage as they age. On an older, brittle three tab roof, opening a wide repair area may damage adjacent tabs or reveal that a durable tie in is not practical. That does not automatically require a full roof replacement. It does mean the proposal should state how far the roofer expects to open the roof and what happens if the surrounding shingles cannot be lifted intact.
Permit requirements vary among the municipal permit desks across St. Louis County. A limited repair may be treated differently from replacement of the skylight, structural curb work, or a larger reroofing project. The contractor should identify the governing municipality and state in writing who will confirm and obtain any required permit.
What to ask
Before approving work, ask questions that force the proposed repair into clear terms:
- Is the damage in the glazing, frame, flashing, shingles, or more than one of those? Ask for a close photograph and a wider photograph that shows its position.
- Will the shingles be removed around the skylight? If not, ask how the condition of concealed step flashing will be established.
- Is this a sealant repair, a reflashing job, a glazing replacement, or a complete skylight replacement? Those are different scopes with different expected service lives.
- Will a compatible flashing kit be used? The written scope should name the skylight model when it can be identified and explain the flashing method.
- What happens if the deck or curb is soft? Ask for a unit price or approval process for concealed wood replacement before the opening is exposed.
- Can the existing shingles be tied back in without cracking? This is especially important on an older three tab roof after cold weather.
- Who is responsible for interior finishing? Roof work may stop at the shaft even when stained drywall and paint remain inside.
- Does the municipality require a permit for this scope? Get the answer tied to your actual address, not a general statement about St. Louis County.
Keep the storm inspection separate from conclusions that the photographs do not support. Keys Roofing can document visible damage and put a written scope with photos and measurements in your hands. The homeowner remains responsible for dealing with any insurer. Missouri law forbids a roofing contractor from representing or negotiating a homeowner's insurance claim.
If you see broken glazing, an open gap, or active water entry, move belongings away from the area and place a container beneath the drip if it is safe to do so. Do not stand directly below cracked glass. Call Keys Roofing at (314) 220-2333 and describe whether the skylight is cracked, leaking, or simply marked after hail. That distinction helps determine whether the first visit needs temporary weather protection or a dry roof inspection.