Porch roof repair
How are porch roofs repaired?
The short answer
A porch roof is repaired by finding the exact spot where water gets in and putting that right: refixing or replacing slipped tiles, renewing the lead flashing where the porch meets the house wall, patching or relaying a worn flat covering, or swapping a cracked sheet. Porch jobs are small, and the roof is low enough to reach from a ladder or a light tower. The survey comes first, then a single price in writing.
What goes wrong on a porch roof, how each fault is mended, and what changes the cost of a small job at the front door.
Where a porch roof lets the weather in
A porch roof is a small roof with the same weak points as a big one. The most likely culprit is the meeting line with the house wall, where a strip of metal has to bridge two surfaces that move at different rates. Next come the edges, where rain runs off into a gutter that may be tiny and blocked, and then the covering itself.
Porches come in several builds. Some have a little pitched roof of tiles or slates on timber rafters. Some are flat, finished in felt, GRP or EPDM, which is a synthetic rubber sheet. Some have a lead-covered canopy, and some are glazed or fitted with polycarbonate. Craigweil in Aldwick shows the lead kind: Arun's conservation area statement notes leaded roofs on a number of entrance porches.
The signs are usually plain. A brown stain on the ceiling inside the porch, damp plaster on the house wall above the door, or a drip at the same spot every time it rains. There is no loft to climb into, so the survey works from outside and from underneath.
Mending a tiled or slated porch
On a pitched porch the usual repair is small. Slipped or cracked tiles come off, any rotten batten under them is renewed, and sound tiles are refixed with a mechanical clip or nail rather than left to sit on their own weight. Under the tiles run battens, the thin laths that carry them. If the felt beneath has split, that is dealt with while the covering is off, because a new tile over a failed underlay only hides the fault for a season.
At the side, the verge is where the tiles stop short of the end wall, and those edge tiles need fixing down properly. Along the top, a ridge needs its tiles held mechanically, following BS 5534.
When the roof is old and the tiles are brittle, that is the advice once we have looked at it. A porch slope is small, so the plain verdict may be to relay all of it while the access is in place.
Lead at the wall, and flat porch coverings
The line where a porch roof meets the house is sealed with a flashing: a strip of lead tucked into a cut in the brickwork and laid down across the porch covering. Lead is the repair we prefer, since it moulds to the wall and holds its form. MyJobQuote puts lead flashing life at over 80 years, a typical figure and no promise.
Flat porches fail differently. The felt blisters or splits, or the membrane lifts at the edge. Ponding, where water sits after rain, points to a poor fall. BS 6229:2025 keeps a minimum finished fall of 1:80, and roofers build nearer 1:40 to leave a margin. A small flat area can be patched if the rest of the covering is sound. If the whole surface is tired, a new membrane is a better use of money than another patch.
Whatever covers the porch, the right repair is no more work than the cause demands.
Gutters, boards and the small parts underneath
Porch roofs often leak because of what surrounds them. A short run of gutter that has filled with moss and leaves overflows down the wall. The fascia (the front board holding the gutter) and the soffit (the lining beneath the overhang) can soak and rot. Once a fascia is soft, the gutter sags, water runs behind it, and the damp reaches the timber structure of the porch itself.
We look at these in the same visit as the covering. Clearing a gutter and refixing it at a proper fall costs little. Replacing a rotten board costs more, but leaving it means the next gale or heavy shower finds a weak edge.
Wooden porches add another job: the timber posts and the beam that carry the roof. If they have softened at the top, the roof is moving, and no flashing will stay watertight on a moving structure. We photograph anything like that and say what a carpenter would need to do.
What changes the price of a small job
Porch repairs sit at the small end of roof work, and the price follows the fault more than the size. Checkatrade's roof repair guide, last updated in June 2026, puts lead flashing repairs at £50 to £70 per metre and says all its costs exclude VAT. For flat roof small repairs, Less (March 2026) gives £150 to £500. These are typical UK figures and not our quote.
Access is the other lever. A porch sits low, so a ladder or a small tower often reaches it, and that keeps the bill down compared with a roof that needs a full scaffold. Our answer on repairing a roof without scaffolding explains when a ladder is enough. A porch over a narrow path or a step may need a tower set up carefully, and that is something we check on the survey.
Other repairs of this kind are covered in our guides to the lean-to roof and the bay window roof, and the whole range is on the roof repairs page.
Related questions
Porch roof questions
Is it worth repairing a cracked polycarbonate porch sheet?
A single cracked sheet is usually swapped for a new one cut to size, with the fixings and seals renewed. If the whole roof has gone brittle and yellow, replacing every sheet is the better route. Polycarbonate roofs typically last around 10 to 15 years, according to HomeBuilding and the Eco Experts.
Why does my porch ceiling stain only when the wind blows?
Wind-driven rain pushes water sideways under a lifted tile or behind a failing flashing at the wall, so the leak shows only in certain weather. Note which direction the rain comes from and send us photographs, then we can narrow the search at the survey.