Flat Roofing in Blandford Forum

Where they actually leak. Nine leaks in ten start at a junction. An upstand against the house wall wants a cover flashing dressed into a chase, or lead over an apron on an older detail. A parapet needs the coping bedded properly and a cavity tray behind it, which is the bit that gets left out. Verges need an edge trim and a drip so the water is thrown clear instead of running down the render.

What we put back. EPDM rubber is one sheet with bonded laps and no flame, which suits a garage or a porch. GRP fibreglass goes on wet over new plywood and sets as a single skin, good where there are a lot of angles. Three layer built up felt, torch on with a mineral cap sheet, still takes more foot traffic than anything else. Single ply is welded and comes into its own over the larger communal areas.

Repairs that take a morning. A blister, a bubble under the surface, a hairline crack or a failed seam where two sheets have lifted apart are all patchable. We cut back to sound material, bond or weld in the new piece and dress the edges down. Where the covering has gone brittle right across, we will say so rather than sell you a repair that leaks again by autumn.

Deck, joists and falls. Wet chipboard decking comes off. Plywood that gives underfoot goes with it and OSB usually goes back in its place. The joists get checked while they are open, and the falls are corrected with firrings or tapered insulation so water reaches an outlet instead of pooling in the middle. Ponding is not cosmetic. It is what finds the next weak seam.

Warm roof, cold roof and building control. A warm roof carries PIR over the deck with the vapour control layer beneath, which keeps the dew point clear of the timber. A cold roof leaves the insulation between the joists and has to be ventilated, or condensation and interstitial damp quietly rot the boards. BS 6229 sets out the build and Approved Document L the standard, and a large re-cover goes through building control on a building notice.

Rooflights, pipes and the rainwater. A lantern or a rooflight only stays dry if its kerb is built up high enough and the covering is dressed over it, so the skylight sits proud of any standing water. A Velux in a dormer cheek, a loft hatch and every soil pipe or vent pipe gets a proper collar. Then the rainwater outlet, hopper, gutter and downpipe are checked, because a blocked outlet floods a sound roof.

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 single garage off a back lane, a two storey rear extension in a terrace and a communal roof over a block of flats are three different jobs before a sheet comes off the van. 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.

We cover Blandford Forum and out to Bryanston, Stourpaine, Spetisbury and the Tarrant villages across DT11, working up from Bournemouth. 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.