Why Skylight Replacement Is More Than Swapping a Unit
Most skylights do not fail all at once. The seal goes and the glass fogs. The acrylic yellows and cracks at the corners. The flashing rusts or the caulk dries out and a drip shows up every March. At some point, repairing it stops making sense.
A real replacement fixes the whole assembly, not just the glass. We pull the old unit, check the curb and deck for rot, lay new Grace Ice & Water Shield, fit a new factory flashing kit matched to your roof and set the new unit. Putting a new skylight into old flashing is the most common replacement mistake we see, and it is why some “new” skylights leak in their first winter.
The 3 Ways We Replace Skylights in the GTA
- Residential skylight replacement for leaking, fogged and outdated home skylights, same-size from $2,200.
- Commercial skylight replacement for offices, libraries, retail and industrial roofs, $6,000 to $30,000.
- Old skylight removal and replacement for 1980s acrylic domes, rotted curbs and units you want gone for good.
Residential Skylight Replacement
Kitchen Skylights
Kitchens see steam and grease, which speed up seal failure on the original glass. Replacement is the right moment to switch to a venting Velux VS or solar Velux VSS so cooking heat and steam have somewhere to go at the ceiling instead of fogging the new glass. Most kitchen replacements land between $2,200 and $4,800 same-size.
Bathroom Skylights
Fogged glass and mould on the shaft are common, especially on 1990s acrylic domes over tubs and showers. New laminated Low-E glass plus an insulated shaft with a proper vapour barrier fixes the condensation as well as the glass, and a venting upgrade lets the shower humidity out at the ceiling instead of dripping down the tile.
Hallway and Stair Skylights
The light here is often blocked by yellowed acrylic domes that block about 40% of the daylight they used to let through. Clear Low-E 272 glass changes the whole floor in one day, and we usually pair the stairwell unit with a Fakro TGR sun tunnel on the upstairs landing so the dark hall no longer drags on the rest of the house.
Bedrooms
Replacement plus a blackout blind is a popular combination, and it is the cheapest moment to add it because the new unit is already on the roof. Most bedrooms go with a manual Velux blind at $180 to $320 plus install, or a motorized one at $380 to $650 if the window is over a stair or vaulted ceiling you cannot easily reach.
Attics and Lofts
Older loft conversions often have undersized units that were sized to whatever hole the previous owner happened to cut. Enlarging during replacement is worth considering because the framing is already opened, and the jump from a 2x3 to a 2x4 or even 4x4 Velux FS turns a dark corner of the attic into the brightest room in the house.
Sunrooms
Failed glass roofs get new laminated Low-E panels or a full custom rebuild depending on what we find when we pull the old units. Sunroom glass roofs are usually 1980s or 1990s sealed units with broken thermal seals and rusted frames, and a same-size swap to modern laminated Low-E glass cuts summer heat and rain noise dramatically.
Heritage Homes
Rosedale and Cabbagetown homes get low-profile replacements with copper flashing where the roof calls for it, and we file the heritage committee paperwork as part of the quote. We carry copper stock in the truck for those jobs so we can hand-form step and counter-flashing on site instead of waiting on a metal shop.
Commercial Skylight Replacement
Libraries and Public Buildings
Our City of Toronto Public Library branch skylight replacement on the Danforth (2024) was phased around public hours over three weeks, with the reading room kept open the whole time. Public-sector jobs need $5M CGL, full WSIB clearance, COI on request and method statements the facility team can hand to their insurer, and our package has all four.
Office Towers
Our $65,000 Vaughan Metropolitan Centre office tower replacement ran one week around tenants, with a swing-stage rig set up Saturday morning and the parking spots below netted off for safety. Office towers need phased work, after-hours scheduling and a crew lead who answers the property manager’s email within an hour, which is how we run our commercial jobs.
Retail and Restaurants
Replacing tired domes and atria without closing the store is most of the work, and we schedule tear-out and set-in before opening or after last call. Restaurant atriums especially need a crew that works clean, vacuums nightly and protects seating, because the dining room is open the next morning at 11.
Warehouses
Old polycarbonate and wired glass bays swapped for modern insulated units with fall-protection screens sized to your rafter spacing. Most distribution-centre bays run 4x8 or 5x10 and we batch the replacements in groups of four to eight so the rigger only mobilizes once and the warehouse stays mostly operational.
Condo and Multi-Residential
Amenity rooms, corridors and penthouse units, with board paperwork handled, COI on file with the management company and access coordinated through the concierge. Condo skylight work usually runs on a board-approved vendor list, and we are on most GTA management companies’ lists with $5M CGL and WSIB clearance ready to send.
Specialty Replacement Projects
Acrylic Dome to Glass Conversions
We pull the old acrylic dome, fit a curb adapter or tear off to the deck and install a Low-E glass Velux or Fakro unit. It cuts summer heat gain noticeably and quiets rain noise a lot, which is the surprise most homeowners mention after the swap. See old skylight removal and replacement.
Brand-Switch Curb Retrofits
Non-Velux units replaced with a Velux FCM curb-mount on an adapter curb, so we do not have to tear off to the deck and reframe. We do Wasco, old Fakro, Sun-Tek, Wasco and unbranded retrofit curbs all the time, and the FCM curb-mount is the go-to unit because it sits on almost any existing curb. See Velux skylight replacement.
Fixed to Solar Upgrades
Replace a fixed unit with a Velux VSS that opens by remote, closes itself when the rain sensor trips, and runs entirely off a solar panel built into the frame. No electrician, no new wiring, no invoice for chasing a circuit through the ceiling, and the upgrade is the cheapest moment to do it because the crew is already on the roof.
Permanent Removal
If you no longer want a skylight, we close the opening with framing, sheathing and roofing matched to the rest of the roof, then leave the interior ceiling ready for paint. Permanent removals usually run cheaper than a same-size replacement because there is no new skylight unit on the quote, just labour and roofing material.
Materials for Replacement Work
| Item | Standard on every replacement |
|---|---|
| New unit | Velux FS, FCM, VS, VSS or Fakro FTT sized to the opening |
| Flashing | New factory kit (EDL, EDM, EDW) or hand-formed step flashing |
| Underlayment | Grace Ice & Water Shield around the full curb |
| Glass | Low-E 272, laminated interior pane |
| Curb | Repaired or rebuilt if rot is found |
All units meet CSA A440 and many carry Energy Star Canada certification for the Toronto climate zone.
Our Replacement Expertise
We remove a lot of skylights, which means we see exactly how they failed. Nine times out of ten it is not the unit itself, it is a flashing detail that was skipped or caulk that took the place of real flashing. That is why we never reuse old flashing.
What Actually Stops Homeowners From Replacing a Skylight
“It only leaks a little.”
In our opinion, a small leak is the best time to act, before the drywall, insulation and framing get wet. Small leaks rarely stay small, and the bill for an interior drywall and insulation rebuild usually ends up costing more than the flashing repair would have. Honestly, the cheapest leak is the first one.
“Replacement must mean a big construction job.”
Same-size replacement is usually one day with no permit, and the crew is in and out before you lose a full day of work. We pull the old unit, check the curb, lay new Grace Ice & Water Shield, fit a new factory flashing kit and set the new Velux or Fakro unit, then touch up the trim inside. Most replacements leave the house cleaner than we found it.
“Maybe I can just recaulk it.”
Caulk buys a season at most, and on a Toronto roof that means one winter before the freeze-thaw cracks it again. It does not fix failed flashing or a dead glass seal, and nine times out of ten the caulk we are called to scrape off is hiding the actual leak source. A proper re-flash with a Velux EDL kit outlasts the shingles around it, and that is what we warranty.
“I don’t know if it needs replacing or repair.”
That is what the free assessment is for. We tell people to repair rather than replace all the time, and our repair-diagnostic leaflet (which we email after the visit) lays out the unit’s age, leak history, frame condition and glass seal status so you can decide with the facts in front of you. Honestly, if repair will outlast the next ten years we will say so.
Skylight Replacement Timeline
Assessment
Free visit, honest repair-or-replace call, quote in two business days. The crew lead checks the data plate, the glass, the curb, the flashing and the interior for stains, then writes up the call with photos so you can see what we are recommending and why. Itemized quote in your inbox within two business days, with permit fees listed as their own line when a permit is needed.
Ordering
Units arrive in one to three weeks through our Velux Canada and Fakro Canada dealer accounts; permits only for enlargements, filed at cost plus our admin time. We order the unit only after the building department stamps the permit, so you are not paying to store a skylight in a garage waiting on a roof.
Replacement Day
Old unit out, new flashing and unit in, usually one day. The same in-house WSIB-covered crew tears off, checks the deck for rot, lays new Grace Ice & Water Shield, fits a fresh factory flashing kit and sets the new Velux or Fakro unit, then signs off against our founder’s replacement checklist at the end of the day.
Finish
Trim touch-ups, warranty registration, old unit disposed. We register the new Velux or Fakro manufacturer warranty on the spot, hand you a written lifetime leak-free warranty on our flashing, and email the closing package with photos, the warranty PDFs and the invoice all in one PDF for your records.
Skylight Replacement Cost in Toronto: What You Are Paying For
New Unit
The largest single cost, varying by model from a Velux FS fixed glass at the entry level to a Velux VSS solar venting unit at the top, with Fakro FTT thermal units in between. Every unit we install meets CSA A440 and most carry Energy Star Canada certification for the Toronto climate zone, which keeps the rebate paperwork simple when you go to file it.
Removal and Disposal
Included in every replacement quote, so you are never paying a surprise line for hauling the old unit away. The trailer pulls up the morning of the replacement, leaves with the old skylight, cardboard and packaging the same day, and the driveway is back to normal before dinner.
New Flashing Kit
Never skipped, even when the old flashing looks fine from the driveway. Upgrades run $185 to $385 depending on whether you need a Velux EDL for shingles, EDM for metal, or EDW for tile and slate, and we lap Grace Ice & Water Shield a full 18 inches up the curb so freeze-thaw has nothing to grab. Putting a new skylight into old flashing is the most common replacement mistake we see.
Curb and Deck Repair
Only if rot is found, quoted before we continue, so you can decide whether to add the work or stop and call it out separately. Most curb rot is a 2x4 and a piece of sheathing that we can rebuild in an hour, but a soft deck means stopping to let you see it before we cut further. Honest pricing on this line is what most callbacks are about.
Enlargement Framing
Headers, sheathing and a permit when the opening grows, with engineering sign-off if the new opening cuts more than one rafter or truss. Enlargements run $3,800 to $7,500 residential because we are reframing to the new size, doubling headers for Toronto snow load and filing the permit as its own line on the quote rather than hiding it in labour.
Interior Touch-Ups
Trim and minor drywall around the shaft, with water-stained drywall from old leaks replaced at the same visit when needed. We bring a drywall finisher on replacement days where the shaft has been stained, so you are not scheduling a separate painter to make the ceiling look right again.
Skylight Replacement vs Installation vs Repair: Which Service You Need
Replacement swaps a unit in an existing opening. Installation creates a new opening. Repair keeps your current unit going when the frame and glass are still sound. Over 20 years old and leaking again? Replace.
Fixed, Venting or Solar: Choosing Your Skylight Type
Replacement is the cheapest moment to upgrade. Fixed Velux FS for light only, venting Velux VS for bathrooms and kitchens, solar Velux VSS for high ceilings and automatic rain closing.
Skylight Replacement Timeline in Toronto: What to Expect Week-by-Week
Assessment in week one, units arrive in weeks two to three, replacement takes a day, finishing wraps that week. Enlargements add permit time.
Why GTA Homeowners Trust Us With Replacements
We have been replacing skylights across Toronto and the surrounding GTA for over twenty years and more than 2,000 installs, certified for both Velux and Fakro since 2004. Every crew is in-house and WSIB-covered with no subcontractors, every quote itemizes unit, labour, permit, flashing and disposal on separate lines, and every opening is detailed to OBC 9.7 for the new window and OBC 9.26 for the roofing. CSA A440-rated glass, a new factory flashing kit on every replacement and a fresh written lifetime leak-free warranty round out what you are actually paying for. Trust us, you’re in good hands.
