The short answer
When a conservatory gutter drips, the culprit is usually a failed joint, a choked outlet, a run that has sagged out of fall, or a gap where the roof sheets meet the channel. Box and ogee gutters leak in different places. A cleaned and resealed joint often solves it, but a cracked or sagging run is better replaced. The survey looks at the whole edge, not just the drip.
Box gutter or ogee: which do you have?
Two shapes dominate. An ogee gutter has an S-shaped profile, a bit like decorative moulding, and is common on older uPVC conservatory frames. A box gutter has a square or rectangular section and often forms part of the roof edge itself, sitting between the roof and a cill or fascia. Many modern systems use a box or hidden profile that is fixed to the frame, with the roof sheets or glazing running into it.
The shape matters because leaks start in different places. An ogee leaks at the joints and the stop ends, where sections or end caps are sealed. A box gutter often leaks where the roof sits over its back edge, or through its own seams, because water that gets past the roof sheets goes straight into the room instead of down the pipe.
Look closely at the end of the run. A drip from the end cap, a stain along the wall below a joint, or green growth on the outside show where to start.
The usual causes of a leak
Conservatory guttering faces a harder life than most. It is small, so it blocks quickly, and it sits under trees or beneath a main roof that dumps water onto it. These are the faults we meet most often.
- Blocked outlet. Leaves and moss stop water leaving, and it spills over the edge or backs up under the roof sheets.
- Failed joint. The seal at a union or stop end dries out and splits. In an ogee run it drips along the face of the fascia.
- Lost fall. A gutter that has slipped on its brackets holds water instead of shedding it. Makers usually advise a gentle slope towards the outlet, roughly 1:600 to 1:350 depending on the system.
- Cracked section. UV and age make old plastic brittle, and a knock or a ladder can crack it.
- Roof-to-gutter gap. If the roof sheet ends short of the gutter or has lifted, rain runs behind it.
A good first test is to pour a bucket of water along the gutter and watch where it escapes.
Where the roof meets the gutter
The seam between the roof and the gutter is the detail that fails most quietly. On a polycarbonate or glass roof, the sheets or units finish just over the edge of the gutter so the water drops into it. If the sheets have shrunk, slipped or been cut too short, or if the gutter has sagged, there is a gap and water runs down the back instead of into the channel.
Sealant is often used to patch this junction, and it can help in the short term. It is a stopgap, not a fix, because the movement that opened the gap will open it again. Our page on conservatory roof sealant explains where sealing works and where it hides a bigger problem.
On a conservatory roof that matches the house, the design may differ again. See our note on matching a conservatory roof to the house for how the edge details change.
Repair, reseal or replace?
A blocked outlet or a joint with a failed seal is a repair. We clear it, check the fall, refit or reseal the joint and test again with water. A sagging run on loose brackets can be re-hung with new brackets at the right spacing, which for many systems is about every 500mm on straight runs of a small system, with manufacturers' guidance setting the exact figure.
A cracked, warped or faded gutter is better replaced, along with stop ends and outlets that no longer match. Mixing old and new sections rarely works because the profiles and the seals vary between makers. When the roof covering is close to worn out as well, doing both together saves a second round of access and gives a cleaner finish along the edge.
If the leak shows inside rather than outside, it may not be the gutter at all. The page on conservatory roof vents covers another source of drips that looks like a leak.
Keeping a small gutter clear
An annual clear-out is the minimum, with a second after leaf fall if trees stand close by. Rinse the channel with a hose and watch that it empties along its whole length. If the downpipe discharges onto the ground or into a soakaway, look there too, since a blocked drain at the bottom backs everything up. Never rest a ladder on the roof sheets, because polycarbonate and glass will not take the weight, and a hairline crack made in passing becomes a leak by the next storm. Brush out the stop ends as well, since silt gathers there first, and look for green staining on the fascia, which tells you where water has been overflowing.
A conservatory attached to a house often receives runoff from the main roof as well, so a full gutter above makes the one below work harder. Look at both at the same time.
What we do about it
The visit covers the gutter, the roof edge and the downpipe, and you get photographs of each fault. A written quote follows. If a cleared outlet and a resealed joint put things right, that is the job quoted, and a full run of new guttering appears only when the old one is beyond saving. For the wider picture of what a conservatory roof can be, see conservatory roof options or the main conservatory roof replacement page.
Our workmanship is guaranteed for 10 years in writing, and the garden is left tidy. Ring 01793 626096, use WhatsApp or send the enquiry form.