Water staining around a skylight, a draft near the shaft, or a fogged glass unit can turn a bright room into a problem area fast. If the ceiling below the skylight is bubbling, the trim is damp after rain, or melting snow seems to leave a drip trail, the issue may be tied to flashing, curb details, or the skylight unit itself.

Kitchener Roofing Company handles skylight installation and repair for homes across ON, N2G 2M9, with work that takes roof slope, shingle layout, flashing transitions, and attic moisture conditions into account. We inspect the skylight, surrounding roofing, and drainage path so the fix addresses the source, not just the visible stain.


Skylight problems

Skylights fail for different reasons, and the symptoms can overlap. A leak does not always mean the glass is broken. Often the real issue is at the curb, the step flashing, the counterflashing, or the roof covering around the opening. In Southern Ontario, freeze-thaw cycles can widen small gaps, and wind-driven rain can push water into weak details around the frame.

Homeowners usually notice one or more of these signs:

  • Wet drywall, peeling paint, or yellow marks around the skylight shaft
  • Condensation or fog between glass panes on sealed units
  • Drips after rain or snowmelt near the inside trim
  • Drafts that suggest air leakage around the skylight frame
  • Loose shingles, cracked sealant, or lifted flashing at the roof opening
  • Moisture on the attic side of the roof deck near the skylight curb

When we look at a skylight, we also check how the surrounding roofing sheds water. Valleys, nearby penetrations, roof pitch, and eavestrough drainage can all influence whether water sits near the unit or moves away as intended.


Installation choices

A skylight should suit both the room below and the roof assembly above it. The right choice depends on roof slope, framing layout, ventilation near the attic, and whether the opening is being added during a reroof or to an existing roof system. Kitchener Roofing Company installs and replaces skylights with attention to the roofing details that keep the opening dry over time.

Fixed and vented units

Fixed skylights are used when the goal is daylight only. Vented skylights can help release warm air, but they need careful flashing and sealing where the unit meets the curb and roofing. The wrong unit for the roof or room can create condensation concerns or maintenance headaches later.

Curb details

Some skylights sit on a built curb, while others are deck mounted. The curb height, fastening pattern, and flashing sequence matter because water can collect around the edges of the opening. We assess whether the curb needs repair, rebuilding, or fresh weatherproofing before any new unit goes down.

Roofing tie-in

The skylight must integrate with the roof covering, not sit as a separate feature. That means the underlayment, ice-and-water membrane, step flashing, and counterflashing need to match the roof slope and material. On asphalt shingle roofs, shingle layout around the opening should preserve drainage and avoid unnecessary cut lines where water may linger.


Repair work

Many skylight leaks can be traced to worn flashing details, aged seals, or roof material breakdown around the opening. Before recommending replacement, we evaluate the skylight glass, frame, curb, surrounding shingles or membrane, and the roof deck area underneath. That helps separate a small repair from a larger assembly issue.

Flashing repairs

Step flashing and counterflashing are common failure points where skylights meet the roof. If these pieces have shifted, corroded, or were installed without enough overlap, water can follow the roof line beneath the covering. Repair work may include replacing damaged flashing pieces, resealing transitions, or rebuilding the tie-in around the curb.

Glass and seal issues

Fog between panes often points to a failed seal on insulated glass. That does not always create an immediate roof leak, but it can reduce clarity and show that the unit is aging. We assess whether the skylight can be repaired at the frame level or whether a replacement is the smarter long-term move.

Common repair situations include:

  1. Minor roof leak at the curb

    Usually tied to flashing, sealant breakdown, or nearby shingle damage.

  2. Interior moisture

    May point to condensation, poor ventilation, or an air-sealing gap around the shaft.

  3. Exterior wear

    Can involve cracked glazing, brittle gaskets, or exposed fasteners at the skylight assembly.


During reroofing

Skylight work often makes the most sense when the roof covering is being renewed. That gives us a clear view of the roof decking, sheathing, and underlayment around the opening. If the shingles are being removed, it is easier to replace worn flashing, adjust the skylight curb, and rebuild the water-shedding layers in the right order.

For asphalt shingle roofs, we pay close attention to starter shingles, ice-and-water membrane placement, valley terminations, drip edge, and the way the shingle courses return to the skylight. On metal roofs, panel layout and trim transitions must leave no weak point where water can be driven uphill by wind. On flat roofing, the skylight curb and membrane tie-in need a different approach altogether, especially with EPDM, TPO, or modified-bitumen assemblies.

If the skylight opening has been leaking for a while, we also inspect the roof deck for soft spots, staining, or moisture damage. Catching those issues during reroofing can prevent a hidden problem from being covered over.


Repair or replace

Not every skylight should be patched again. Some units are worth saving, while others have reached the point where repeated sealing is only delaying a larger fix. We help homeowners look at the whole picture before work starts.

Signs replacement makes sense

  • Repeated leaks from the same skylight opening
  • Failed insulated glass seals with persistent fogging
  • Cracked frame components or warped curb materials
  • Visible wear around the flashing and roofing interface
  • Moisture damage that has spread to the surrounding roof deck

Signs repair may be enough

  • Localized flashing damage with a solid skylight unit
  • Minor seal deterioration around trim or curb edges
  • Small roof-covering defects near the opening
  • Leak symptoms that started after wind or freeze-thaw exposure

When we recommend a repair, it is because the skylight structure still has useful life. When replacement is smarter, we explain why the current unit is no longer giving the roof assembly a dependable weather seal.


Ventilation and moisture

Skylight problems are not always caused by rain. Condensation can form when warm, moist indoor air reaches a cold surface near the skylight shaft or attic space. If attic ventilation is weak, moisture can accumulate around roof framing, insulation, and the underside of the roof deck.

That is why we consider soffit intake vents, ridge vents, and the overall attic airflow pattern when diagnosing a skylight issue. A sealed-looking room can still show moisture problems if the attic side of the assembly is trapping humidity. In winter, attic frost and freeze-thaw cycles can make the symptoms worse by adding repeated wetting and drying around vulnerable materials.

We also look at the skylight shaft insulation and the surrounding air sealing. Even a good skylight can seem faulty if the interior opening is allowing warm indoor air to reach cold roof surfaces.


Our process

Skylight work should be orderly, clean, and based on what the roof is actually doing. Here is how we approach each project at Kitchener Roofing Company:

  1. Inspect the opening

    We look at the skylight, roof covering, flashing, curb, and nearby drainage points.

  2. Find the source

    We trace the leak path or condensation source before touching the finish materials.

  3. Plan the fix

    We decide whether the issue calls for repair, replacement, or coordination with other roof work.

  4. Install or restore

    We complete the skylight work with the right underlayment, flashing sequence, and roof tie-in.

  5. Check the finish

    We confirm the surrounding shingles, trim, and interior area reflect a clean, weather-tight result.

That process matters because a skylight opening is part of a larger roof system. If one layer is ignored, leaks can come back through a different path.


Common questions

Can a skylight leak without visible glass damage?

Yes. Many leaks begin at the flashing, curb, or roof covering around the skylight, not the glass itself. Water can enter at a small opening and travel before it appears inside.

Why does my skylight fog between panes?

Fog between panes usually points to a failed insulated glass seal. That is different from surface condensation and often shows the unit is aging or no longer sealed as intended.

Do skylights need special flashing?

They do. Skylights need flashing that matches the roof slope and roofing material, along with underlayment and water-shedding layers that guide moisture away from the opening.

Can a skylight be installed during a roof replacement?

Yes, and that is often a practical time to do it. The roof covering is already open, so the skylight, flashing, and surrounding materials can be integrated together more cleanly.

What if the area around the skylight feels drafty?

Drafts may come from air leakage around the skylight frame, the shaft, or nearby attic connections. We check the opening, insulation, and surrounding roof details to find the source.

Does attic ventilation affect skylight moisture problems?

It can. Poor attic airflow may allow condensation to form around the skylight shaft or roof deck. Intake and exhaust ventilation should work together to reduce moisture buildup.


Request skylight help

If your skylight is leaking, fogging, or showing signs of wear, Kitchener Roofing Company can inspect the full roof-to-skylight connection and recommend the right next step. We serve homeowners across ON, N2G 2M9 and nearby communities with skylight installation, repair, and reroof tie-in work that respects the rest of the roof system.

Call +16477005472 to request a free roofing estimate and talk through the skylight issue before it spreads to the ceiling, insulation, or roof deck.

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