A leaking conservatory is frustrating because water often appears a long way from where it gets in. It can run along a glazing bar, down a frame and drip onto the floor several feet away. This guide covers the common places conservatories leak, which of those sealant can fix, and which need a glazier or roofer instead.
Where conservatories usually leak
- Roof glazing bars, where the roof panels meet the bars and the seals or gaskets have shrunk or slipped
- The wall junction, where the conservatory roof meets the house wall
- The ridge and hips on the roof
- The frame-to-wall joint down each side, where the frame meets the brickwork
- Glass-to-frame joints on side windows and doors
- The gutter, at joints, end caps and outlets
Leaks sealant can usually fix
Glazing silicone is the right fix for failed joints between glass and frame, gaps where a frame meets the wall, and small gaps at glazing bar ends where the original seal has failed but the panel is sound. Gutter joints and end caps can often be resealed too. Our gutter sealing service covers these.
The joints need to be cleaned of old sealant, dirt and moss, and dried before new sealant goes on. Glazing work needs a silicone suited to glass and to the frame material. Our glazing silicone service covers conservatory roofs and frames, rooflights and glass-to-frame joints.
Leaks that need a glazier
Misting between the panes. If a double-glazed unit has condensation inside it, between the two sheets of glass, the seal of the unit itself has failed. That can’t be fixed with sealant around the outside. The unit needs replacing by a glazier.
Cracked glass or damaged panels. Sealant over a crack is not a lasting repair. The panel needs replacing.
Badly fitted or slipped roof panels. If panels have moved out of position, they need refitting before any sealing.
Need it done properly? Mr Mastic covers the South East, London and Scotland, with a one-year guarantee on every job. Call or email for a quick quote.
Leaks that need a roofer or builder
Where the conservatory roof meets the house, there is usually a lead or other flashing. If the flashing has lifted, cracked or come away from the wall, that is roofing work. A bead of sealant along a failed flashing may slow a leak, but it rarely solves it. We don’t do roofing, so we will say if that is the problem.
Water can also come through the house wall above the conservatory, from a failed gutter, cracked render or damaged pointing. That needs fixing at source.
Tracking down the leak
- Note when it leaks: in any rain, or only in wind-driven rain from one direction?
- Look for staining, drips or water marks on bars and frames, and trace them upwards.
- Check the gutter is clear. A blocked gutter can overflow into the conservatory roof joints.
- Look at the wall junction from outside, from the ground or a window. Don’t climb onto the roof.
See our gutter and fascia guide for more on gutter leaks.
Rooflights and shower screens
The same rules apply to other glazing around the home. Rooflights can leak where the glass meets the frame or where the frame meets the roof. The first can often be resealed. The second may be roofing work.
Inside, glass shower screens rely on sealant at the base and along the wall. When it fails, water runs out under the screen. That is a straightforward reseal with a sanitary silicone.
Quick answers
Can I seal a misty double-glazed unit?
No. Misting between the panes means the unit’s own seal has failed. The unit needs replacing by a glazier.
Is it safe to walk on a conservatory roof?
No. Conservatory roofs are not designed to be walked on. Leave roof work to people with the right access equipment.
Will resealing stop all conservatory leaks?
Only those coming through failed joints. Flashing, cracked panels and failed units need other trades.
Related services
More advice
- Leaking Gutter Joints and Fascias: Can Sealant Help?
- Window Mastic: When to Replace It and How
- Coloured Sealant and Colour Matching
- All advice
This guide is general information about sealant work. It isn’t legal, fire-safety or structural advice; for those, speak to a qualified professional.