Flat roofs fail at
the edges and joints,
not the middle.
Most flat roof leaks come from the details: an upstand that is too shallow, a fall that lets water sit, an outlet that blocks, a flashing that has come away from the wall. We find which one it is, repair what can be repaired, and replace the roof properly when it cannot.
Rear extensions, dormers,
shops and offices.
On London houses, flat roofs sit over rear extensions, dormer tops, bay windows, garages and back additions, and almost every Level 3 survey has something to say about one of them. On commercial buildings they are usually the whole roof: shops with flats above, offices, restaurants, industrial units and blocks of flats.
The failures are the same on both. Water ponds where the fall is too flat and finds the weakest joint. Upstands against walls are too low, so splash and snow get behind the covering. Lead or mortar flashings crack away from the brickwork. Outlets and gutters block with leaves and silt and the roof floods back. Old felt blisters, splits at the laps and goes brittle in the sun. Each of these is visible on inspection, and photographs of each are what we send you.
Patch it, overlay it,
or strip it back.
A localised failure on a roof that is otherwise sound is a repair: re-dress the flashing, rebuild the upstand, re-lay the failed area, clear and re-form the outlet. Where the covering is tired but the deck underneath is dry and firm, an overlay or a liquid applied system can add years. Where the deck is wet, soft or rotten, the only lasting answer is to strip it back and replace it.
For homes, EPDM rubber laid in one sheet and GRP fibreglass are the usual choices, with torch on felt still common on larger areas. On commercial roofs, single ply membranes and built up felt systems are typical, and liquid applied coatings suit roofs with a lot of plant and penetrations. Whatever the material, the detailing at edges, upstands, outlets and penetrations decides how long it lasts.
Replacing most of a roof covering usually brings in the Building Regulations requirement to bring the insulation up to current standards, which often means a warm roof build up with the insulation above the deck. We tell you whether that applies before quoting, so the price you see is the price of a compliant roof.
Occupied buildings,
access and records.
Commercial roofs bring their own constraints. The building usually stays open, so work is phased and temporary weatherproofing goes on at the end of every day. Access is by tower, mobile platform or scaffold with edge protection, priced separately so you can see it. A risk assessment and method statement are issued before work starts.
For landlords and managing agents we provide a condition report with photographs, which is what you need for planning budgets, a lease end or a sale. Planned inspections twice a year, clearing outlets and gutters before and after leaf fall, catch most problems while they are still a repair. That can sit inside a property maintenance schedule.
Older commercial roofs sometimes contain asbestos in felts, cement sheets or the products used around them. If the building is pre 2000 and the work will disturb the roof, an asbestos survey comes first.
Questions we get
asked most.
Get a written
price.
Monday to Saturday 9am to 8pm, Sunday 9am to 3pm. All London boroughs.
Message us on WhatsAppSend a photo of the roof or the ceiling below and we will tell you what we think is happening.
How a flat roof job runs.
1. Inspection and photographs
We go up, look at the covering, the upstands, the outlets, the flashings and the deck where it can be seen, and check the ceiling below. You get photographs of what we found and what we think is causing the leak.
2. Written quote
Repair, overlay or full replacement, with the reasoning, the materials, the access and whether insulation upgrades apply, all set out in writing before anything is agreed.
3. Strip, deck and insulation
On a replacement the old covering comes off, the deck is checked and any wet or soft boards are replaced. Where the regulations require it, insulation goes in as a warm roof build up.
4. Covering and detailing
The new covering is laid, with the upstands, edge trims, outlets and flashings detailed properly, because that is where flat roofs fail.
5. Clear up and handover
The site is cleared, gutters and outlets checked, and you get the photographs of the finished roof and any guarantee from the material manufacturer where one applies.
Which covering suits which roof.
EPDM rubber
A single sheet with very few joints, suited to rear extensions, garages and dormers. It copes well with movement and gives a long life when the edges and upstands are detailed properly.
GRP fibreglass
A laminated finish that can take foot traffic with the right top coat, which makes it a common choice for balconies and small roofs that are walked on.
Torch on felt
Built up in layers and still common on larger domestic and commercial roofs. Modern felts last far longer than the old pitch and gravel roofs they usually replace.
Single ply and liquid coatings
Single ply membranes suit large commercial roofs. Liquid applied coatings suit roofs crowded with plant, pipes and penetrations, and can extend the life of a sound roof.
Often needed
alongside this.
Areas we cover.
We take flat roof work across all 32 London boroughs. Most of our work is in west London, in Shepherd's Bush, Hammersmith, Fulham, Kensington, Chiswick and White City, and in south west London, in Putney, Wandsworth and Wimbledon. We also work in south east London, in Greenwich, Blackheath and Lewisham.
If your property is outside these areas, call us anyway. We travel across London and will tell you honestly if a job is too far to price properly.