Roofing services
Skylight replacement: the unit, the flashing and the curb
Skylight replacement removes an old skylight, checks the opening, and installs a new labeled unit with a new flashing kit woven into the roof.
Written by HyreRoof Research Desk Primary-source research and fact checking
The short answer
Skylight replacement removes an old skylight, checks the opening, and installs a new labeled unit with a new flashing kit woven into the roof. Many skylight leaks come from the flashing or from condensation, not the glass, so the first question is whether the unit has failed or only the seal around it.
What should you know before replacing a skylight?
Water at the frame after rain is a flashing leak. Droplets on the glass on cold days is condensation. Fog between the panes is a failed glass seal.
Skylights are tested with their own flashing. Reusing old flashing on a new unit is a common leak source.
Skylight glazing has its own rules, including screens under some glass types.
A skylight near the end of its life is best replaced while the roof is open anyway.
Is the skylight leaking?
| What you see | What it usually means |
|---|---|
| Water at the frame or ceiling after rain | The flashing or the roof around it. A reflash may be enough if the unit is sound. |
| Droplets on the inside of the glass in cold weather | Condensation from indoor humidity. New flashing will not fix it. |
| Fog or haze between the panes | The insulated glass seal has failed. The glass or unit needs replacing. |
| A cracked or crazed plastic dome | Sun and hail damage. The dome or unit is replaced. |
What should the roofer check?
Maker, model and size, so the replacement fits the opening.
Especially on the uphill side, where debris and water collect.
On a low-slope roof, whether it stands high enough above the roof surface.
Signs of long-running leaks or rot around the opening.
Bathrooms and kitchens with skylights often show condensation.
How is a skylight replaced?
A course or more on each side, so the new flashing can be woven in.
And its flashing. The opening is protected if rain is coming.
Rotten curb or deck is replaced, and the opening is squared to the new unit.
Following the maker’s instructions, with the self-adhered membrane they specify around the frame.
Head, side and sill pieces that lap with the shingles so water runs over, not behind.
The interior trim and shaft are made good, sometimes by a separate trade.
Replace the unit, or only reflash?
| Situation | Usual answer |
|---|---|
| Sound unit, failed flashing | Reflash with the maker’s kit, if one still exists for that model. |
| Failed glass seal or cracked dome | Replace the glass or the unit. |
| Roof being replaced | Replace an older unit now, while the shingles are off around it. |
| Opening no longer wanted | Remove the skylight and frame and deck over the opening. That is framing and roofing work. |
What it costs: what the quote should itemize
A skylight quote mixes a product, roofing labor and often interior work.
| Factor | Why it changes the number |
|---|---|
| The unit | Fixed, vented, solar-powered or tubular, with the model named. |
| The flashing kit | Matched to the unit and to the roof covering, which differs for shingle, tile and metal. |
| Size change | A different size means reframing the opening, inside and out. |
| Opening repair | Rotten curb, deck or framing found once the old unit is out. |
| Interior finish | Drywall, paint and trim in the shaft. |
| Roof type and pitch | Tile and steep roofs take more labor. |
| Electrical | Powered vented units may need an electrician. |
No price ranges yet, on purpose. HyreRoof publishes a price range for a job only once it holds at least 12 dated, sourced quotes for it, and we do not hold them for this work yet.
Until then, use the factors above to read a quote, and price your own numbers in the roof cost calculator or set quotes side by side in the estimate comparison tool. The cost guide explains every line.
Questions to ask before you sign
How can you tell?
The maker’s, for this roof type?
On a low-slope roof.
Is it in this price?
The maker’s on the unit and yours on the install, both in writing.
Where does skylight replacement go wrong?
Old metal rarely fits a new unit exactly and can void the maker’s leak warranty.
Sealant around the frame is not flashing. It fails in a season or two.
If the problem is indoor humidity, a new skylight will still drip.
Your inquiry
Tell us about the work
Nothing goes to a roofer unless you agree.
A person reads it and replies by email, free and with no obligation. Matching is not live yet, so this is not a quote. If water is coming in now, call a local roofer directly and check their license first.
Find a Roofer
One short form: your address and how to reach you. A person at HyreRoof reads it and replies.
Questions
Should I replace my skylights when I replace my roof?
Why does my skylight drip only in winter?
What does the code say about skylight glass?
Can a skylight be removed instead?
Written and audited by
HyreRoof Research Desk
Primary-source research, data analysis and fact checking
We are a research desk, not a sales floor. We read the statute, the licensing board’s own pages, the code section or the federal dataset ourselves, and every figure we publish carries the document it came from and the date we retrieved it.
Where a number cannot be traced to a primary source, we publish the shorter page and say what we could not verify.
On our first study that rule removed a Minnesota exam statistic and left two states blank. Those gaps are on the page, not in a file somewhere.
- 155
- primary sources read and cited
- 53
- government domains among them
- 181
- citations carrying a retrieval date
- 11
- research studies published
How this desk works
- Primary sources only. Statutes from the legislature’s own publishing system, licensing rules from the board that issues the license, datasets from the agency that collected them. Never a directory, an aggregator or another guide.
- Three states, not two. A requirement is recorded as verified present, verified absent, or not verified. Folding the third into the second would turn an unchecked cell into a factual claim.
- Retrieval dates on everything. Regulation changes. A citation without the date it was read is not a citation.
- Failures are published. When a source blocks automated retrieval we record the failure and leave the row empty, rather than filling it from a secondary summary.
- Authorship is organizational. Research is attributed to this desk, never to an invented expert. Outside commentary, where used, is attributed to named and verifiable people.
Authorship on this site is organizational: the analysis belongs to the desk rather than to a named individual, and we do not publish credentials we do not hold. Our editorial policy sets out how we source, date and correct what we publish.
Sources & retrieval dates
Information on this page is general and may vary by location, building code, roof design, insurance policy and your own circumstances. It is not insurance, legal or engineering advice.
HyreRoof is not a roofing contractor: we do not repair, replace or inspect roofs, and we do not supervise or warrant roofing work. This page explains the work so you can judge a quote and a contractor.