Troubleshooting guide
Conservatory roof leaking: where water usually gets in
A leak can start from several places on a conservatory roof. Find out which joints, seals and gutters usually let water through, what the signs look like inside your home, and when a specialist needs to take a closer look.
Where the conservatory roof meets the house wall
Most conservatories are built against an existing wall of the house. The lead flashing that seals the gap between the new roof and the old brickwork takes a lot of punishment. Over time it works loose, cracks, or pulls away from the mortar.
Water running down the house wall hits this joint first. If the flashing has failed, it travels behind the conservatory frame and drips onto the internal sill or runs down the plaster. You might see a dark tide mark on the wall above the windows before you notice any dripping.
A specialist roofer checks the entire length of the flashing for gaps. Sometimes the fix is as simple as re-pointing the lead back into the brickwork. Other times the lead needs replacing because it has thinned out or split along a fold. Either way, the problem rarely resolves itself once the seal breaks.
Glazing bar seals and rubber gaskets
Glass and polycarbonate panels sit inside aluminium or uPVC glazing bars. Rubber gaskets hold them tight and keep rain out. These gaskets shrink as they age, especially on south-facing roofs where the sun bakes them every afternoon.
When the rubber hardens and pulls back, a channel opens up along the edge of the panel. Rain follows the slope of the roof straight into the gap. Inside, you will see water tracking along the top of the glazing bar rather than falling freely from the ceiling.
Replacing individual gaskets is possible, but finding the exact profile matters. A fitter who works with conservatory roofs carries the common shapes and can press a fresh seal into the bar without removing the whole panel. If the glazing bars themselves have warped or spread apart, a replacement roof is usually the more reliable route.
Valley gutters on shaped conservatories
Victorian and Edwardian conservatories have facets that angle away from each other. Where two roof slopes meet, a valley gutter channels the water forward. Because valleys collect runoff from two directions, they handle twice the volume of a standard gutter.
Leaves, moss and wind-blown debris settle in these troughs. Once the outlet blocks, water backs up and spills over the sides, soaking the frame beneath. On older structures the valley gutter lining may also have cracked along its centre seam.
Clearing a valley gutter requires reaching the ridge safely. A specialist uses long-handled tools or access equipment to scoop out the blockage without scratching the lining. If the material has split, they cut a new tray to fit the exact angle of the roof junction.
End caps, ridge covers and vent surrounds
Every hole cut into a conservatory roof needs a trim to shed water. Ridge end caps cover the peak where the glazing bars converge. Roof vents have their own raised frames and rubber collars.
These small plastic and metal parts expand and contract at different rates to the main roof. Screws work loose. Sealant dries out and flakes away. Water finds the path of least resistance, usually trickling down the inside of a glazing bar or pooling around the vent handle.
Because the leak starts high up, it often lands far from the actual fault. A specialist traces the moisture trail back uphill to locate the failing cap or collar. They then reseal or replace the specific fitting rather than treating the whole roof surface.
Blocked eaves gutters and overflowing downpipes
The gutter running along the front edge of the conservatory catches everything the roof sheds. In autumn, nearby trees fill it quickly. Once the gutter overflows, water pours down the outside of the frame and pools at the base, eventually seeping under the bottom track.
Downpipes blocked by compacted leaves cause the same problem from the inside out. Water fills the gutter faster than it can drain, forcing it over the lowest point.
A specialist clears the run, flushes the downpipe and checks the brackets. Sagging gutters hold standing water even after the rain stops, which accelerates corrosion on metal systems and encourages algae growth on uPVC. Re-aligning the fall so water moves briskly toward the outlet prevents the next overflow.
Ask a specialist to look at your roof
Send a few details about the leak. A separate firm that handles conservatory repairs will read them and reply with what to do next. There is no charge and no obligation to book anything.
- No cost to ask
- No booking required
- Separate repair firms