A skylight is a hole in the roof that has been made weatherproof with a kerb, flashing, seal and glazing unit. When any of those parts age, water or moist air can show up as a drip, a stain or fogging between panes. This guide covers the problems Sydney property owners see most often, the signs that a unit needs attention, and how to decide between a targeted repair and a replacement.
Common skylight problems
Leaks around the flashing are the issue most people notice first. Wind-driven rain can enter where the flashing has lifted, corroded or been poorly dressed into tiles or metal sheets. Sealant that has dried, cracked or pulled away from the frame is another frequent path.
Condensation is different from a leak. Warm indoor air meeting a cold glazing surface can leave moisture on the pane or in the shaft. Persistent fogging between double-glazed layers usually means the sealed unit has failed, not that the roof flashing is open.
Cracked glass, crazed acrylic or a distorted dome can follow impact, hail, thermal stress or UV ageing. Once the glazing is broken, the unit is no longer a reliable weather barrier even if the flashing still looks tidy from below.
Signs a skylight needs repair
Ceiling marks that appear after rain, damp plaster around the shaft, peeling paint or a musty smell near the opening all justify a closer look. Water that only appears in northerly or easterly storms can still point to a flashing or soaker detail rather than the glazing itself.
From the room you may also see daylight at the frame edge, a shaft that feels wet, mould on the reveal, or droplets that run down the inside of the pane on cool mornings. None of these signs tell you the exact defect on their own. The roof side of the unit, the flashing and the surrounding covering need to be inspected together.
Preventive maintenance
Most skylight failures build up slowly. A short inspection after severe weather, plus a planned check of seals and drainage, can catch lifted flashings and blocked soakers before the ceiling is involved.
- Clear leaves and debris from the kerb, soaker and nearby gutters
- Look for cracked or missing sealant around the frame after summer heat
- Check the surrounding tiles or sheets for cracks, lifted edges and loose fixings
- Watch for new fogging, drips or staining after storms
- Keep foot traffic off the unit during other roof work
- Have solar, air-conditioning or antenna work detailed so it does not disturb the flashing
Repair or replace
A localised flashing repair, new sealant or a replacement pane can be enough when the kerb, shaft and surrounding roof are sound. Repair is usually the practical path for a single failed seal or a small, well-defined leak path.
Replacement is more likely when the glazing unit has failed, the dome is badly UV-degraded, the frame is corroded, or the flashing design no longer suits the roof covering. Older acrylic bubbles and some out-of-production models are difficult to patch in a lasting way.
If the rest of the roof is being renewed, it is often cleaner to replace the skylight at the same time so the new covering, sarking and flashings are detailed as one system. An inspection can separate an isolated skylight defect from a wider roof issue.
Frequently asked questions
Why is my skylight dripping if it is not raining?
That is often condensation. Moist indoor air cooling on the glazing can run down the pane. A rain-timed drip is more likely to be a flashing, seal or covering defect.
Can a cracked skylight pane be repaired?
Some units accept a replacement pane or dome when the frame is sound. Widespread crazing, a failed sealed unit or a corroded frame usually points toward replacing the skylight.
Does a leaking skylight always mean the unit itself has failed?
No. Water often enters at the flashing or at tiles and sheets beside the kerb. The surrounding roof needs to be checked before the glazing is blamed.
How often should a Sydney skylight be checked?
A visual check after severe weather, plus a planned inspection with the rest of the roof, is a sensible rhythm. Leafy sites and older units benefit from more frequent debris clearing.
Should I replace a skylight during a re-roof?
If the unit is aged, leaking or no longer matches the covering, replacing it while the roof is open avoids cutting a new flashing into a finished surface later.