Dayton Roofing Services
Most skylight leaks aren't the skylight. We'll find out what's actually failing before you pay to replace anything.
Dayton, OH
A stain on the ceiling below a skylight looks like a simple diagnosis, and it usually isn't. The unit is often fine. What has failed is the flashing kit around it, or the curb underneath it, or something further up the roof that's sending water down the deck to the first obstruction in its path.
That matters because a new skylight fitted into the old flashing leaks again in the first heavy rain — and the homeowner has paid for a unit that was never the problem.
We repair and replace skylights throughout Dayton, Kettering, Centerville and Beavercreek, and the inspection comes before the recommendation.
The Diagnostic
Four places, and only one of them is the skylight itself. Select each to see what fails and what it needs.
The most common leak source. The step and head flashing where the unit meets the shingle courses. This is the most common leak source by a wide margin, and the one a replacement unit alone does not fix.
The substrate, not the glass. The raised frame the unit sits on. Rot at the curb means the substrate failed, not the glass — and a new unit fastened to soft wood won't seal.
The one case that is the unit. The perimeter seal around the glass itself. This is the unit failing, and it's the case where replacement is genuinely the answer.
The skylight is fine — look upslope. Water travelling down the deck from a failure further up the slope, appearing at the skylight because that's the first thing in its path. Not a skylight problem at all.
The Decision
If the roof is being replaced, replacing the skylight at the same time is usually the better economics — the flashing has to come off either way, and doing it twice costs more than doing it once. That's a real recommendation, not an upsell, and it's worth saying.
The Most Common Miss
This is where most of the skylight work actually happens.
When a roof comes off, every skylight flashing kit comes off with it. Re-using old flashing on a new roof is one of the most common shortcuts in the trade, and it's why a brand-new roof can leak at the skylight within a season.
We fit a new flashing kit whenever the surrounding roof is replaced. On a re-roof it's a small proportion of the job; on a callback it's the whole job plus interior repairs.
Learn more about our roof replacement and roof repair services.
Worth Knowing
Water appearing around a skylight in winter is often condensation, not a leak — warm humid interior air meeting the coldest glass in the house. Bathrooms and kitchens are the usual culprits.
How to tell, roughly: a leak follows rain, condensation follows cold weather and humidity. Condensation appears evenly around the perimeter; a leak usually runs from one point.
Condensation between the panes is different — that's a failed sealed unit and it does mean replacement.
That distinction is worth stating because it's the one case where we'd tell someone their skylight isn't leaking at all.
Local Conditions
A skylight is a hole in the roof with a frame in it, and every junction is a place water can get in. It's also the coldest surface in the room in winter and the hottest in summer, so the seals and flashing cycle through more movement than anything else on the roof.
Ice dams make it worse — water backing up under the shingles reaches the skylight's head flashing from above, which is the one direction flashing isn't designed to shed. Learn more about ice dam removal.
The Process
Why AlphaOne
Flexible financing options are available, and every job is backed by the AlphaOne Advantage Workmanship Warranty.
A stain on the ceiling usually gets blamed on the skylight itself, and that’s often wrong. The leak could be the flashing kit around the unit, the curb underneath it, the glazing seal, or water traveling down the roof from somewhere higher up the slope. An inspection traces the water to its actual source before anything gets recommended.
It depends on which part failed. A flashing or curb problem is usually a repair — the unit itself is sound. A failed glazing seal, a cracked frame, or a unit at the end of its service life usually calls for replacement. We give an honest read after inspection rather than defaulting to either answer.
A leak tends to follow rain and run from one point. Condensation follows cold weather and humidity and shows up evenly around the perimeter of the frame — it’s warm interior air meeting the coldest glass in the house. Condensation between the panes themselves is different and does mean the sealed unit has failed.
It’s the metal flashing — step and head flashing — installed where the skylight meets the surrounding shingle courses. It’s what actually keeps water out at that junction, and it’s the most common source of skylight leaks by a wide margin. A new skylight installed over an old, failing flashing kit will leak again.
Yes. Skylight replacement is a standalone job in most cases — we remove the old unit, fit the new one, and install a new flashing kit into the existing roof around it.
If the skylight is due for replacement anyway, doing it at the same time as a roof replacement is usually the better economics. The flashing has to come off either way, and doing that work twice costs more than doing it once.
It means the seal on a sealed, multi-pane unit has failed and let humid air in between the panes, where it condenses. That’s not the same as ordinary surface condensation on the inside of the glass, and it does mean the unit needs to be replaced.
There’s no single number that holds up — it depends on the unit’s quality, how well the flashing was installed, how much sun and weather exposure the roof gets, and whether the surrounding roof has been replaced (and the flashing renewed) since the skylight went in. A unit with poor flashing can fail years before a well-installed one with worse specs would.
Sometimes. Limited rot at the surface can often be repaired. Once rot has gone deeper into the structure, the curb usually needs to be rebuilt rather than patched — fastening a new unit to soft wood won’t hold a seal. We assess the extent during inspection.
That’s a different job from repair or replacement — it means cutting the roof deck, framing a new opening, and building the shaft down to the ceiling, not just working with an existing opening. Whether that’s the right project for a given roof is assessed case by case during inspection.
It depends on what’s actually failed — a flashing repair, a curb rebuild, and a full skylight replacement are different scopes of work. We inspect first and provide a clear written estimate rather than quoting a number before we’ve seen the roof.
That depends on the cause and your policy. Damage from a sudden covered event, like storm or hail impact, is generally more likely to be covered than damage from normal wear or age. We can document what we find during inspection to support a claim — check with your insurer on your specific coverage.
In most cases, yes. Flashing and curb repairs can typically be done in cold weather, though heavy snow or ice on the roof can affect scheduling and safety for exterior work. We’ll assess conditions and let you know what’s realistic when we inspect.
Yes, skylight repair and replacement work is backed by the AlphaOne Advantage Workmanship Warranty, the same as our other exterior services.
A professional inspection, an honest recommendation on repair versus replacement, and a clear written estimate for your skylight project.
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