Skylight Leaks in West Michigan: Why They Leak and How They Get Fixed
A skylight is a great thing right up until water starts coming through it. Then it stops being a feature and turns into the most nerve-racking leak in the house, because it is dripping straight into your living room. We get the calls every spring and every time the snow melts fast. The good news is that most skylight leaks trace back to a short list of causes, and most of them are a fix, not a tear-the-roof-off emergency. You just have to find where the water is actually getting in.
Here is the plain version of why skylights leak in our climate, how to tell a real leak from harmless condensation, the difference between the two ways skylights are mounted, the West Michigan winter angle that catches a lot of people, and what an honest repair looks like.
Why a skylight leaks before the rest of the roof
Think about how a shingled roof keeps water out. Each course of shingles overlaps the one below it, so water just runs down the surface and off the edge. Nothing to get past. Now cut a hole in that surface and drop a window into it. Suddenly the water has a seam to find, running all the way around the unit, and the only thing stopping it is the metal flashing and sealant wrapped around the skylight.
Anywhere two different materials meet on a roof is a weak point. A skylight is a weak point on all four sides. That is not a knock on skylights, it is just physics, and it is why they show up so often when we go looking for the source of a leak. The flashing does the real work, and flashing is exactly the part that ages, lifts, and corrodes over years of Michigan sun and freeze-thaw. When people ask us where a roof is most likely to leak, skylights are near the top of the list right alongside valleys and chimneys.
The four ways skylights actually leak here
When we open one up, the water is almost always coming from one of these.
| Cause | What's happening | The tell |
|---|---|---|
| Failed flashing | The metal flashing around the skylight has lifted, corroded, pulled loose, or was installed wrong, letting water track under it | Stains on the drywall around the skylight that worsen over time; the most common real leak |
| Dead glass seal | The seal on an insulated-glass unit has blown, fogging the panes and sometimes weeping at the frame | Foggy or cloudy glass that won't wipe clean; older units |
| Condensation (not a leak) | Warm, humid indoor air meets cold glass and sweats, especially over a bath or kitchen in winter | Even moisture on the glass and inner frame in cold weather that wipes away |
| Ice dam above the unit | Ice backs meltwater up against the top flashing and under the surrounding shingles | Dry all summer, leaks every hard winter; lines up with eave icicles |
The condensation one matters because it sends people chasing a leak that does not exist. If the glass is sweating in January over a steamy bathroom and the moisture wipes off, that is humidity, not a roof problem, and the fix is ventilation, not flashing. A real leak stains the framing and ceiling around the unit, shows up with rain or snowmelt, and gets worse each round. When you are not sure where water is coming from, our guide to finding where a roof leak starts walks through how to trace it back to the source.
Curb-mounted vs deck-mounted, and why it matters
Skylights get installed two ways, and the difference changes how they leak and how they get fixed.
Curb-mounted
The skylight sits on a raised wooden frame, called a curb, that's built up above the roof surface. Shingles and flashing run up the sides of the curb, so the unit sits a few inches proud of the roof. These shed water and snow well, which is a real advantage in our climate, but the leak point is the flashing where the roof meets the curb.
Deck-mounted
The skylight mounts low, right down on the roof deck, for a sleeker look and a lower profile. Most modern units come with a manufacturer flashing kit designed for the specific model. They look cleaner but sit closer to the water running down the roof, so the flashing detail has to be perfect, and a kit installed wrong is a leak waiting for the first storm.
Either way, the flashing is the whole ballgame. A quality unit with sloppy flashing leaks, and an older unit with proper flashing stays dry. That is why we don't just reseal the top of a skylight and call it done. We look at how the flashing ties into the shingles, the same way we'd check the metal in a roof valley.
The West Michigan winter angle
Here is the pattern we see more than any other on skylights: dry all summer, leaks every February. That is almost never the skylight unit failing. That is ice.
A skylight sits in the slope of the roof with snow and meltwater running down past it all winter. Grand Rapids runs 40 to 60 freeze-thaw days in a typical winter, so snow on the roof melts during the day and refreezes at night, over and over. When ice builds up below the skylight or at the eave, meltwater backs up behind it, ponds against the top edge of the unit, and works its way under the top flashing and the shingles around it. The skylight is fine. The ice put water somewhere it was never meant to go. The National Weather Service Grand Rapids office tracks the freeze-thaw and snow patterns that drive this season after season. If your skylight only leaks in deep winter, the fix is about ice management and flashing, not a new window.
Warning signs to watch for
You can catch a skylight leak early, and early is the whole game with any roof leak. Watch for these:
- Water stains or brown rings on the drywall of the skylight shaft or the ceiling around it.
- Drips or running water from the corners of the skylight during or right after rain or a fast snowmelt.
- Peeling paint, soft spots, or mold on the shaft walls, which means water has been getting in for a while.
- Foggy or cloudy glass between the panes, the sign of a blown seal on the unit.
- A musty smell near the skylight even when you can't see the water.
A skylight leak does not stay small. The water runs down the inside of the shaft framing, soaks the drywall, and feeds mold in a dark, enclosed space you rarely look at closely. What starts as a faint ring on the ceiling turns into rotted framing and a much bigger repair if it sits. That is the whole argument for getting eyes on it the first time you see a stain.
How a skylight leak gets repaired
The first job is finding the real entry point, because the stain inside is often not directly under where the water gets in. Water can enter at the top flashing and track down the framing before it shows up. So we open up the area around the skylight, pull back the surrounding shingles, and look at the flashing and the deck underneath instead of guessing from the ceiling.
If the flashing failed and the skylight unit is still sound, the fix is to replace the flashing, lay fresh ice-and-water shield around the opening (which the Michigan Residential Code calls for in vulnerable areas like this), and re-lay the shingles so they weave into the new flashing the right way. Any decking that got wet and soft comes out first. Done correctly, the repaired skylight is better sealed than it was before it leaked.
If the unit itself has had it, the glass seal is blown, the frame is shot, or it is past 15 to 20 years old, we'll tell you straight that replacing the unit is the smarter money than re-flashing a window on its way out. And if your whole roof is near the end, the best time to deal with an aging skylight is during the roof replacement, when the shingles around it are already off and the new flashing can tie cleanly into the new roof. Whatever the situation, a real roof repair starts with finding the actual leak, not slapping caulk on the top. If a storm is what drove water in, our storm damage response gets it stopped fast. The install standards good flashing work follows come from the National Roofing Contractors Association.
Stain Around a Skylight or a Drip When It Rains? We'll Find It
Our team opens up the skylight flashing, finds exactly where the water gets in, and shows you photos before we quote the fix. Free inspections and quotes across Grand Rapids, Wyoming, Kentwood, Holland, Muskegon, Kalamazoo, and Lansing.
Request a Free QuoteFrequently Asked Questions
Why do skylights leak more than the rest of the roof?
A skylight is a hole cut through the roof, so its waterproofing depends entirely on flashing and sealant rather than the overlapping shingles that protect the rest of the surface. Anywhere two materials meet is a weak point, and a skylight has a seam running all the way around it. That makes it one of the most common places a West Michigan roof leaks, especially as the flashing ages and the unit's seals give out.
How do I know if my skylight is leaking or just sweating?
Condensation shows up as even moisture or drips on the glass and inner frame, usually in cold weather on a humid room like a bathroom, and it wipes away. A true leak stains the drywall and frame around the skylight, shows up during or right after rain or snowmelt, and comes back worse each time. If water tracks down from the corners of the shaft or the ceiling beyond the skylight, it is a leak, not sweat.
Can a leaking skylight be repaired or does it need replacement?
It depends on where the water is getting in. If the flashing failed and the skylight itself is sound, re-flashing and resealing fixes it and is a real repair. If the glass seal has blown, the unit is fogged, or the skylight is past 15 to 20 years old, replacing the unit is the smarter money. We open it up, find the actual entry point, and tell you which one you are looking at instead of guessing from inside.
Do ice dams cause skylight leaks in West Michigan?
Yes. A skylight sits in the roof slope where snow and meltwater run past it, and an ice dam above the unit backs water up against the top flashing and under the shingles around it. With 40 to 60 freeze-thaw days a winter in Grand Rapids, that happens often. A skylight that stays dry all summer and leaks every February is almost always an ice-dam and flashing problem, not a failed unit.
How long should a skylight last in Michigan?
A quality skylight unit lasts about 15 to 25 years, but the flashing and sealant around it often need attention sooner, especially after 10 to 15 Michigan winters of freeze-thaw. The insulated glass seal is usually what ages out first, showing up as fogging between the panes. If your roof is getting replaced, that is the right time to reflash or replace an older skylight while the shingles around it are off anyway.
Should I replace my skylight when I replace my roof?
If the skylight is more than 10 to 15 years old, yes, replace or at least reflash it during the reroof. The flashing ties into the shingles, so doing it during a roof replacement means the new flashing is woven into the new roof correctly instead of patched in later. Replacing an old unit while the area is already open costs far less than coming back to do it after the new roof is on.