Flat roofing in Bryanston

Back additions, dormer cheeks and porch roofs. A good deal of the older housing around here is terraced, and terraces come with narrow rear additions whose roofs are flat, plus dormers with a flat top and a small roof over the front door. The covering is usually torch on felt or an older three layer built up system finished in mineral surfaced cap sheet, sometimes with a second layer laid over the first to buy time. We strip a section to see the deck, because that is the whole question. Dry plywood or OSB takes a new covering. Chipboard decking that has been sitting wet has to come off and new boards go on the joists. After that it is EPDM rubber, GRP fibreglass or a fresh torch on system, with single ply worth pricing on anything wide and open.

Ponding, falls and the outlet. Water that stays put after the rain has stopped is not a cosmetic problem. Standing water works into every lap and seam and a frost prises them apart. Nine times out of ten the fall was never there, the firrings were cut too shallow, or the rainwater outlet is silted up or has been built over by later work. We rebuild the falls with firrings or tapered insulation so it drains to an outlet, in line with BS 6229:2025 on flat roofs, and we make sure the gutter, hopper and downpipe underneath can take what arrives.

Where a flat roof actually leaks. Almost never in the field of the covering. It is the edge trim, the drip, the apron flashing, the kerb round an opening and the laps. On felt you see a blister, a bubble or a split. On single ply it is a lifted or failed seam. On fibreglass it is a crack where a sharp internal angle has flexed. Repairs begin by taking out whatever has failed. The upstand is rebuilt to a height that will actually hold water back, and every seam is welded or bonded instead of sealed.

Openings, abutments and the build up. A rooflight, a lantern, a Velux, a hatch or a soil and vent pipe needs its own kerb and collar. Against a wall the cover flashing is chased in and formed in lead. On a parapet the coping matters and so does the tray behind it, because a parapet with neither soaks the brickwork while everybody blames the roof. Older roofs here are cold roofs, with insulation between the joists and a dead void above where condensation gathers and interstitial damp rots the deck unseen. A rebuilt roof goes back warm. Insulation board is laid over the deck, the vapour control layer goes beneath the board, and the void that caused the trouble disappears.

No rate per square metre, because the square metres are the easy part and what is under the covering is what decides the job.

Getting to it. A back addition reached through the house, a garage on a shared drive, and a dormer top two storeys up are three different jobs before any covering comes off. A garage or a single storey extension will often come off a tower, anything above a two storey wall wants a scaffold, and the platform has to stand while the deck is open rather than for an afternoon. The work at height rules are why it is a priced line rather than something folded into a rate.

The deck under the covering. A sound deck can be re-covered. Chipboard that has been wet for years, or ply that gives underfoot, has to come off and be replaced, and you cannot tell which you have from the ground or from a photograph. We lift a corner before quoting, because the deck is the single biggest swing in the price.

The falls, and where the water is meant to go. Most flat roofs that fail were never laid to a fall, or the fall runs at an outlet that has since been blocked or built over. Correcting it with firrings is more work than laying a membrane and it is the difference between a roof that lasts and one that ponds. Upstands, edge trims and each outlet are priced one at a time, because that is where the hours and the leaks both are.

Comparing quotes? Ask which system is being quoted and how many layers, whether the deck is being renewed or covered over, whether the falls are being corrected with firrings, how the upstands, outlets and edge trims are detailed, and whether the scaffold and the skip are in the price. Two quotes for the same job are usually two different jobs.

Bryanston sits in a conservation area shared with Blandford St Mary, and that changes the appearance of a flat roof rather than the construction of it. Replacing felt with felt is maintenance and needs no application. Changing what the roof looks like from a road or a footpath is different, and so is adding a lantern, a row of rooflights or a bright new trim along an edge that can be seen. It is a short conversation with Dorset Council and it is much cheaper before the materials are ordered.

There are a number of listed entries around Bryanston, mostly on the school estate rather than in the ordinary housing. If your house is one of them, or a flat roof is attached to one, you need listed building consent even for a like for like repair, and that is a separate thing from planning permission. For the great majority of homes here neither applies and the only decision left is which covering suits the roof.

We cover Bryanston, Blandford St Mary and the streets across the river in Blandford Forum, along with the rest of DT11, and the site visit costs you nothing. You are dealing with Bournemouth Roofing & Building, the trading name of Bournemouth Roofing & Building Ltd, registered in England and Wales, company number 15471719, which you can look up in a minute. Thomas Hannen's business, and he is the one who comes out to price the job, not a salesman. A verified customer's 10 out of 10 on Checkatrade. The visit and the written quote are both free.