Guttrz / Blog / Why is my skylight leaking
Why is my skylight leaking? 5 causes in Ohio homes
The owner inspects every skylight leak himself, sends a photo report the same day, and gives you one written price good for a year.
When you ask why is my skylight leaking, the answer in most Ohio homes is the flashing around the unit, not the glass: caulk used in place of lapped metal, ice backing up at the top edge, a worn seal in the unit, winter condensation, or a roof leak higher up that drains out at the skylight. Guttrz, based in North Canton, inspects skylight leaks across Stark, Summit and Medina counties. The owner inspects it himself, sends a photo report the same day, and gives one fixed written price before any work starts, good for a year.
Why is my skylight leaking? It is the question people ask when a brown ring shows up on the drywall of the light shaft, usually after the first hard freeze or a long autumn rain. In most Ohio homes the glass is fine. The water is getting past the metal and membrane around the unit, or it is not rain at all. This post walks through the five causes we look for first, what you can check from inside, and how to decide between a repair and a new unit. The owner inspects every skylight himself, sends a photo report the same day, and gives one written price good for a year.
Why is my skylight leaking? The five usual causes
A skylight is a hole cut in the roof with a window set in it. Everything that keeps water out happens in the few inches around the frame. These are the five failures behind most calls, roughly in order of how often they turn up.
1. Flashing that was sealed with caulk instead of lapped
Many skylights in older Ohio houses went in years after the house was built, during a kitchen, bath or attic remodel. The person cutting the hole was often a carpenter, not a roofer. The tell is a heavy black bead of roof cement around the frame. Metal flashing works by overlapping, each piece shedding water onto the one below. Caulk works by sticking, and it stops sticking after a few winters. Once a gap opens, water gets under the shingles and runs down the side of the opening.
2. Snow and ice backing up at the top edge
The uphill side of a skylight is a small dam built into your roof. Snow piles against it, the warm glass melts the bottom of the pile, and the melt refreezes at the frame. On the next thaw, water pools behind that ice and climbs under the shingles above. This is why many skylights in Northeast Ohio leak only from December to March. The same physics drives the eave problems covered in our post on ice dams on Ohio roofs.
3. A worn seal in the unit itself
Skylights have rubber seals of their own. The gasket holding the glass, and on a venting model the weatherstrip around the opening sash, dry out and shrink with age. Water then comes through the unit rather than around it. You usually see it as drips on the room side of the glass or a wet sill at the low edge.
4. Condensation that looks like a leak
Cold glass in a warm, damp house collects water the way a cold drink does on a summer porch. On a January morning the inside of the glass beads up, the water runs down to the frame, and it drips onto the shaft. It looks exactly like a leak, and no amount of roof work will fix it.
5. A roof leak higher up that drains out at the skylight
Water that gets in above the skylight, at a cracked shingle, a nail that backed out, or a vent, runs down the top of the roof deck until something stops it. The skylight framing is often the first thing in its path. The stain shows up at the skylight, but the hole is three or four feet uphill.
Is it a leak or condensation?
Timing tells you most of what you need. Write down the date and the weather every time you see water for a couple of weeks.
- Wet during or right after rain: a leak.
- Wet on a thaw day after snow: a leak caused by ice at the top edge.
- Wet on a cold, clear, dry morning: condensation, almost always.
- Wet after a shower or cooking: condensation from the room below, especially in a bathroom skylight.
Condensation is fixed inside the house: run the bath fan longer, lower indoor humidity in winter, and insulate the walls of the light shaft so the drywall stays warm. A unit with single-pane or old double-pane glass will keep sweating no matter what you do, which is one reason people replace it.
What can you check from inside the house?
Take a flashlight and look closely before anyone climbs a ladder.
- Find where the water starts. A stain that begins at the top of the shaft points up the roof. One that starts at a side or a corner points at the flashing on that side.
- Look at the glass. Fog trapped between the panes means the factory seal has failed, and that is a unit problem, not a roof problem.
- Look in the attic if you can reach it. Follow any dark streaks on the roof boards uphill. If they start well above the skylight, the source is elsewhere on the roof.
- Take photos. They help the inspection go faster and show whether the stain is growing.
Do not go up on the roof in winter to look. Snow hides the flashing anyway, and a skylight is a fall hazard in its own right.
Should you repair or replace a leaking skylight?
If the unit is sound and the problem is the flashing or ice at the top edge, a repair that reflashes the existing skylight solves it. The skylight leak repair page explains how that is done. If the glass is fogged, the dome is cracked or yellowed, or the frame is rotting, put the money into a new unit instead, as the skylight replacement page describes. A third case matters too. If the shingles around the skylight are near the end of their life, the leak is a warning about the whole roof, and a tear-off reflashes every skylight as part of the job.
| What you see | Likely cause | Likely path |
|---|---|---|
| Thick black cement around the frame | Caulked instead of flashed | Reflash the existing unit |
| Leaks only on winter thaw days | Ice at the top edge | Reflash with membrane up the slope |
| Drips on the room side of the glass | Worn gasket or weatherstrip | Gasket repair or new unit |
| Wet on cold dry mornings only | Condensation | Ventilation and shaft insulation |
| Fog between the panes | Failed factory seal | New unit |
| Attic streaks start above the skylight | Roof leak uphill | Roof leak repair |
What happens when Guttrz looks at it?
You text your address and a photo of the stain, and we text or call you within the hour. The owner goes up himself, checks the skylight from the roof and from the attic side, and checks the rest of the roof uphill so a leak from somewhere else does not get blamed on the skylight. You get a photo report the same day that names the cause and the fix. The written price is fixed before any work starts and good for a year, and a job minimum applies. Skylights are one of several roof repairs Guttrz handles in Stark County, alongside flashing, pipe boots and drip edge. If the report points to the flashing, the next step is skylight flashing repair from Guttrz.
The owner climbs up to look at your skylight himself, the photo report reaches you the same day, and the written price holds for a year. Request a fixed written price for your skylight leak, or text your address and a photo to (330) 818-5584.
Common questions
Why does my skylight leak only when it snows?
Snow piles against the uphill side of the skylight and the warm glass melts it from below. The meltwater refreezes at the frame into a small dam, and the next thaw pushes water under the shingles above it. The repair is flashing with ice and water shield run further up the slope, plus raking snow off the area after big storms if you can do it safely from the ground.
Is a leaking skylight an emergency?
Usually not, but it should not wait for spring. A slow drip soaks the drywall and insulation in the shaft, and wet framing around a skylight can rot within a few seasons. Put a towel or a pan under it, photograph the stain, and get it inspected before the next long rain or thaw.
Do skylights always leak eventually?
No. A skylight that was flashed with a proper kit and membrane can stay dry for the life of the roof. Most leaking skylights were sealed with caulk, installed without a flashing kit, or have outlived their seals. The age of the unit and how it was put in matter more than the fact that it is a skylight.
Can I fix a skylight leak from inside the house?
Not the leak itself. Everything that keeps rain out is on the roof side. From inside you can only manage condensation, by venting moisture and insulating the shaft, and catch drips until the outside is repaired. Sealing the inside trim just hides water that is still getting into the framing.
Should I remove a skylight instead of fixing it?
Some people do, when the skylight is in a room that does not need the light or it has leaked for years. Removing it means framing the opening closed, decking it, and shingling over it, which is real roof work and costs more than a simple reflash. If the skylight is sound and you like the light, a proper repair is usually the better value.
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Written by Christian Schaffner, owner of Guttrz. Updated November 8, 2026.
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