Should you repair or replace your skylight?
Updated August 2026
← Every repair-or-replace call
Most skylight leaks come from the flashing or the sealant rather than a bad skylight, and that is a $150–600 repair; replace the unit at $600–1,800 installed once the glass fogs, cracks, or the skylight passes 15–20 years. Water almost always enters at the perimeter, where the step flashing, head flashing, and counterflashing meet the roofing, so redoing that detail is roofing work, not glazing work. What genuinely ends a skylight is the insulated glass unit itself. When the seal between the panes breaks, moisture condenses inside and the haze cannot be cleaned off from either side.
The short version
Find out where the water enters before anyone quotes you a new skylight. Run a hose test, starting low on the roof below the unit and working upward in stages while someone watches inside. Water that appears only when the spray reaches the flashing means the flashing failed, and re-flashing with a proper kit costs a fraction of a replacement. Water beading on the inside of the glass in cold weather, with no leak at all, is condensation: an indoor humidity and ventilation problem, not a defect. Age is the other input. Skylights last 15–20 years, and curb-mounted acrylic domes sometimes less, so a leak on a 17-year-old unit deserves a replacement rather than another repair, especially if the roof itself is close to due. Doing both together costs far less than doing them two years apart.
Your situation, decided
| Situation | Verdict | Why |
|---|---|---|
| Leaks only in wind-driven rain, glass still clear | Repair | A $150–600 flashing and sealant fix; the unit is sound |
| Fogging or permanent haze between the panes | Replace | The insulated glass seal has failed and cannot be resealed |
| Cracked glass or a crazed acrylic dome | Replace | Glazing is not repairable; a new unit runs $600–1,800 |
| Water beading inside on cold mornings, roof dry | Not a leak | Condensation from indoor humidity; ventilate the room |
| Unit past 15 years and the roof is being replaced | Replace now | Doing both at once avoids paying twice for flashing work |
| Crank or motor jammed on a venting model | Repair | An operator or motor swap, typically $200–700 |
What each path costs
Repairs typically run $150–600; a replacement is $600–1,800 installed. Skylights last 15–20 years, and the glass seal normally fails before the frame does. Past 15, replace rather than repair, and always replace during a reroof if the unit is close. Price your own number on the home maintenance cost calculator before you commit either way.
The repair-or-replace call is easy when you know the unit's age and service history. OnOtto keeps both, plus the maintenance that delays this decision for years.
Start your home's service log, freeFrequently asked questions
Why is my skylight leaking?
Rank the causes by how common they are. Failed or badly installed flashing at the head and sides accounts for most leaks, followed by dried sealant at the frame joints, then debris damming water above the unit. A blocked or iced-over valley above the skylight pushes water sideways under the shingles. Only after all of those does the glass seal come into it. Clearing leaves off the uphill side twice a year prevents a surprising share of leaks, and ignoring a drip gets expensive fast, as the damage math shows.
Can a fogged skylight be defogged instead of replaced?
Services exist that drill the glass, dry the cavity, and fit tiny vents, for a few hundred dollars. On a skylight, treat that as a stopgap. The unit sits at an angle in full sun and weather, the argon fill and the thermal performance are already gone once the seal breaks, and drilled vents on a sloped roof invite water. If the skylight is still under warranty, and many carry 10–20 years on the glass, file the claim. Otherwise a $600–1,800 replacement restores both the view and the insulation value.
How much more is a venting or solar skylight?
Considerably more than a fixed unit. A fixed skylight installed runs $600–1,800, a manual or electric venting model $1,200–3,000, and a solar-powered venting unit sits at the top of that band, though solar models and their blinds have historically qualified for a federal renewable-energy tax credit, which narrows the gap. A tubular daylight device is the cheap end at $500–1,200 and brings light into a hallway or bath without a full opening. Venting units add moving parts, so expect an operator or motor repair eventually.
Should I replace skylights during a reroof?
If they are past 10 years, yes. The roofer is already stripping shingles around the curb, so the flashing work rides along instead of being billed as its own job, and a new skylight set with a factory flashing kit is the most watertight it will ever be. Putting a 15-year-old unit back into a brand-new roof means opening that roof again in a few years. Ask for pricing both ways when you collect roofing quotes. Coordinating it with the roof decision is the cheapest sequencing available.