Leak or condensation?
Condensation shows up on cold mornings, often when it hasn't rained. You'll see droplets across the inside of the glass or the shaft walls, and it's worse over bathrooms and kitchens where the air is moist.
A leak follows rain. Water appears at one edge or corner, stains spread from a single spot, or drips land in the same place each time. Our guide to condensation or a leak walks through more tell-tale signs.
Common causes of a leaking skylight
- Flashing that's lifted, rusted or was sealed with silicone instead of properly fitted
- Leaves and grit dammed up on the high side, pushing water under the flashing
- Perished rubber seals between the glass or dome and the frame
- A cracked, crazed or brittle acrylic dome, common on older units
- Cracked or slipped tiles right next to the skylight
- On a low-pitched metal roof, no head gutter above the skylight to divert water around it, which BlueScope says these penetrations need
- Gaps where the shaft meets the ceiling, letting roof space moisture through
Old skylight? Check for asbestos first
ASSEA, the federal asbestos agency, lists asbestos cement skylights and roof manholes among older roofing products. If your skylight or the roof around it might be asbestos cement, don't let anyone cut, drill or break it until it's been tested. Read is my roof asbestos?.
How a roofer fixes it
First they find the entry point, usually by checking the flashing, the surrounding tiles or sheets and the seals, sometimes with a hose test while someone watches inside. Cleaning out debris and refitting lifted flashing fixes a lot of leaks on its own.
If the flashing is rusted or wrong for the roof, it gets replaced with a kit made for that profile. Failed seals and cracked domes can sometimes be replaced as parts, depending on the make. If parts aren't available or the frame itself is failing, the whole unit comes out and a new one goes into the same opening.
What you can do now, and what needs a roofer
You can
- Put a bucket and towel under the drip and keep the area dry
- Note whether water comes during rain or on cold, dry mornings
- Look at the skylight from the ground or an upstairs window for leaves or a lifted edge
- Run an exhaust fan or open a window if it's condensation
Leave to a roofer
- Anything on the roof, including clearing debris around the skylight
- Finding the leak and replacing flashing or tiles
- Replacing seals, domes or the whole unit
- Repairing the ceiling plaster once it's dry
Where we'd start
We'd get the cause confirmed before paying for a new skylight, because a refitted flashing or a cleared gutter often solves it for a fraction of the price. If the unit is old, the dome is crazed and the room gets hot, that's when we'd replace rather than repair, and we'd use the chance to upgrade to double glazing.
Want a roofer to take a look?
Tell us the job and your postcode. We match it with a Find My Roofer certified roofer who specialises in that kind of work, and they call you to quote. Your number goes to them alone.