Sloped roofs
Skylight Repair
A skylight is a hole cut in a roof. What keeps water out of that hole is the flashing around it, not the glass in it. Almost every skylight leak is a flashing leak, a curb leak, or condensation that was never a leak at all.
- 24/7 emergency line
- Licence BL272564
- WCB 9892020
- $5M liability
- Free written estimate
Free written estimate
Kristjan will come and look at it
Tell him what it is doing. You get back a written scope and a price, not a range.
City of Calgary licence
BL272564
WCB Alberta account
9892020
General liability
$5,000,000
Written estimate
Free, itemised
That distinction decides the repair. Replacing the unit when the flashing failed puts a new skylight on top of the same problem.
Marku Roofing Repair Ltd. repairs and replaces skylights in Calgary. Call 403-700-7542 for a free written estimate.
01
How a skylight keeps water out
Water arrives at a skylight from above and has to be routed around it. Four components do that work.
Head flashing. Sits above the unit and diverts water to the sides. This is the piece under the most load and the piece that fails first.
Step flashing. Individual pieces woven into each course up both sides, each one lapped by the course above.
Sill or apron flashing. Carries water off the bottom of the unit and back onto the roof surface.
The glazing seal. The gasket between glass and frame. It seals the unit. It does not seal the roof.
A skylight assembled with sealant instead of flashing works for a season or two. Sealant is a consumable. Flashing is not.
02
What fails
Failed head flashing. Corroded, lifted by ice, or never installed correctly. Water enters above the unit and shows on the ceiling below it, which sends most people looking at the glass.
Cracked and shattered glazing. Hail takes skylights before it takes anything else on the roof. The 5 August 2024 Calgary storm produced over 130,000 insurance claims and $2.8 billion in insured damage, the second-costliest insured event in Canadian history. Broken glazing is an insurance claim, and it needs a temporary board-up the same day to stop water and animals entering the building.
Degraded acrylic domes. Acrylic yellows, crazes and goes brittle under ultraviolet exposure. Calgary sits at roughly 1,045 m, and the ultraviolet load at that elevation shortens the service life of every acrylic dome in the city. A brittle dome breaks under hail that would not have marked it when new.
Fogged sealed units. Moisture between the panes of a glass skylight means the sealed unit has lost its edge seal. The roof is not leaking. The unit is finished and the glazing gets replaced.
Rotted curbs and decking. A slow flashing leak soaks the curb and the deck around the opening. By the time the ceiling stains, the framing around the hole is usually wet. The curb gets rebuilt before any new unit goes on it.
Ice damming above the unit. A skylight in the middle of a slope collects the water held back by an ice dam above it. The skylight is where the water shows, not where the problem is.
Stop guessing
Have Kristjan price skylight repair in writing
He gets on the roof, photographs what he finds, and hands you a scope with a number on it. If a repair is the right answer, he says so rather than quoting you a replacement.
Kristjan does the estimates himself. Free, written, and not a range.
03
Condensation is not a leak
Water on the inside face of the glass on a cold morning is condensation. Interior air holds moisture, that moisture meets the coldest surface in the room, and a skylight is the coldest surface in almost every room that has one.
The tell is timing. Condensation appears on cold clear nights and dries by mid-morning. A leak appears during or after rain and snowmelt.
Condensation is a humidity and ventilation problem, and the same mechanism that fogs a skylight also frosts the underside of the sheathing. See attic rain in Calgary.
04
Skylights by roof type
Asphalt shingle. Step-flashed and counter-flashed into the shingle courses. This is the assembly that gets bodged most often, because sealant hides a bad install for a couple of years.
Concrete and clay tile. Needs a profile flashing kit that follows the tile shape. A flat flashing kit under a profiled tile leaves an open channel down both sides of the unit.
Low-slope and SBS. Curb-mounted only. The membrane is carried up the curb and terminated above the highest water the roof will ever hold. 150 mm of curb above the finished membrane is the working minimum. Skylights set flush into a low-slope roof leak, and there is no flashing detail that fixes that.
05
Repair or replace
Repair the flashing when the unit itself is sound, the frame is straight, and the seal is intact.
Replace the glazing when the pane is cracked or the sealed unit has fogged and the frame and curb are still good.
Replace the whole unit when the frame is corroded, the curb has to come apart anyway, or the acrylic has gone brittle across the whole dome.
Replace it during a reroof if it is anywhere near end of life. The flashing has to come off for the reroof regardless, so the labour is already being paid for. A skylight replaced during a reroof costs a fraction of the same skylight replaced on its own two years later.
Cost
What skylight repair costs in Calgary
Calgary market rates, 2026. Ranges, not a quote.
| Work | Typical Calgary range |
|---|---|
| Reseal and reflash an existing unit | $300 to $600 |
| Glazing or sealed-unit replacement | $500 to $1,200 |
| Full skylight replacement, unit and flashing | $1,200 to $2,800 |
| Curb repair where the timber has rotted | add $300 to $900 |
| Remove a skylight and close the opening | $800 to $1,800 |
Roof covering changes the number. A skylight on an asphalt shingle roof is the straightforward case. On concrete tile, tiles have to come off and go back without breaking, and on a low-slope membrane the flashing has to be torched or welded in rather than stepped, so both sit higher in the ranges above.
The honest sequencing note: if the roof is due for replacement within a few years, do the skylight at the same time. Reflashing a skylight into a roof you are about to tear off is money spent twice.
Our own photographs
Work on Calgary roofs
Every photograph on this site is taken on a job we did. No stock libraries.
Checkable, not claimed
Credentials you can verify before we set a ladder up
Marku Roofing Repair Ltd. was incorporated in Alberta in 2022, corporate access number 2024249985. City of Calgary business licence BL272564. WCB Alberta account 9892020. $5,000,000 commercial general liability through Sandbox Mutual Insurance.
VELUX and Fakro are the two units most commonly installed on Alberta houses, with Columbia Skylights and Sun-Tek also seen here. On a replacement it is usually worth moving from an acrylic dome to a glass unit: acrylic yellows and crazes under Calgary sun and hail, and a modern glass sealed unit is both more durable and far better insulated.
No awards, no rankings, no "best in Calgary". A licence number, a WCB account and a policy limit are things you can check yourself.
Meet Kristjan
Answers
Frequently asked questions
Still unclear? A five minute phone call usually settles it faster than reading.
Ask Kristjan directlyMy skylight only leaks in heavy rain. Why?
Volume. A flashing gap that sheds a light rain gets overrun in a downpour. The gap is there in every rain, it just does not pass enough water to reach the ceiling until the roof is loaded.
There is water between the two panes of glass. Is my roof leaking?
No. That is a failed sealed unit. The glazing is replaced and the roof is untouched. Staining on the ceiling around the skylight is a different problem, and it gets traced the same way as any other roof leak.
Can a cracked skylight be patched until spring?
It gets boarded and covered to keep water and animals out, and that is a temporary measure, not a repair. Cut glazing keeps opening under freeze-thaw cycling.
Is skylight damage covered by insurance?
Hail and impact damage generally is. Wear, seal failure and rot generally is not. Photograph the damage before anything is boarded up.
How long does a skylight last?
The glazing and the seal set the life, not the frame. Acrylic domes in Calgary sun go first. Plan on 10 to 15 years from an acrylic dome here and 20 to 30 from a modern glass sealed unit. The flashing usually outlives neither: a skylight that starts leaking at 12 years is far more often a flashing or curb failure than a failure of the unit itself, which is why replacing the glass without touching the flashing tends not to fix the leak.
Do I have to replace the skylight when I replace the roof?
No, but the flashing has to be replaced either way. An old unit left in a new roof is the one detail on that roof that is still at end of life.
Further reading
Before you decide anything
Free written estimate
Get Kristjan on the roof before the next chinook
Freeze-thaw turns a small opening into a large one faster here than almost anywhere else in Canada. Have him look at it while it is still a repair.
Serving Calgary, Airdrie, Cochrane, Okotoks and Chestermere.