Leak repair
Finding where the water is actually getting in
Water travels. It enters at one point, runs along a batten or a rafter, and shows up on a ceiling somewhere else entirely. Repairing the spot above the stain fixes nothing and is the single most common wasted roofing bill.
Where leaks usually start
In London housing stock the same handful of places account for most of them, and only one is the roof covering itself:
- Flashings and abutments, where the roof meets a chimney, a parapet or a neighbouring wall.
- Valleys, especially where two roofs of different ages meet.
- Chimney stacks — cracked flaunching, open joints in the brickwork, or a redundant flue with no cap.
- Parapet gutters and hidden gutters behind a front elevation, which are common on Victorian terraces and invisible from the street.
- Flat roof details, particularly upstands, outlets and the junction with a pitched roof above.
- Penetrations: soil pipes, extract vents, aerials and cables drilled through at some point in the past.
A stain in the middle of a room can come from any of them. That is why the first job is diagnosis rather than repair.
How a leak is traced
Step 1: Inside first
Where the water shows, what shape the stain is, whether it changes with the weather, and what is directly above it in the loft.
Step 2: The loft space
Wet timber, daylight, staining on the felt and the direction the water has run. This is where most leaks are actually identified.
Step 3: On the roof
The details above the suspected entry point, photographed. Flashings, valleys, the stack and any penetrations.
Step 4: Confirm before repairing
Where it is not conclusive, we say so rather than guessing — and where a water test is the sensible next step, we do that instead of quoting for work that may not fix it.
Condensation is not always a leak
A significant share of "leaks" in insulated lofts and converted roofs are condensation: warm moist air reaching a cold surface and running. It stains ceilings in the same way. The fix is ventilation, not roofing, and telling you that is cheaper for you and quicker for everyone.
Leaks we have traced
Case studies are published here as jobs finish, with photographs taken on site before, during and after the work.
Leak questions
The leak only happens in driving rain. Why?
Wind-driven rain gets past details that shed water perfectly well in still weather — an open flashing joint, a gap under a verge, a hairline crack in a chimney. A leak that appears only in a storm from one direction is a useful clue rather than a mystery, and it narrows down where to look.
Can you find a leak without scaffolding?
Usually, yes. Diagnosis is mostly done from inside the loft and from a ladder or tower at the relevant detail. Access for the repair is a separate question and depends on where the fault turns out to be.
My ceiling is stained but it is dry now. Is it urgent?
It is worth looking at, but it is not usually an emergency. What matters is whether the timber above it is still getting wet. A dry stain from a fault that has already been fixed needs decorating; a dry stain from a fault that only leaks in certain weather needs a roofer.
Not sure what your roof needs?
An inspection ends with a written report and photographs, whether or not you go ahead with the work.
Inspection fee: £99.00.