Flat roofing in West Lulworth

Lead, and what replaced it. Some of the older flats here started as lead over boards, with rolls and drips between the bays. Lead splits where it has been fixed too tightly to move and fatigues along a drip. Plenty have since been covered in felt, either a three layer built up system with a mineral cap sheet or a single torch on layer over the top of the last one. That is usually what we are taking off.

The systems that go back. EPDM rubber on a plain rectangle, bonded down in one sheet so there is no lap or seam in the open field of the roof. GRP fibreglass where there are kerbs, corners and upstands to laminate round. Single ply, hot air welded, on a longer run. Where a lead flat is original and seen, lead relaid properly is often the right answer and we will price it that way rather than talk you out of it.

Deck, joists and falls. Under the covering is plywood, OSB or chipboard decking on joists, with firrings creating the fall to the outlet. Wet chipboard swells, gives underfoot and has to come off. On an old building the joists are seldom level, so the fall gets built rather than assumed. A roof holding standing water has a fall problem, and that ponding does more damage over a winter than a gale does in a night. BS 6229 covers falls and drainage, and where re-firring is impractical we form them in tapered insulation.

Insulation and condensation. Where the room below is heated, Part L brings the insulation up with the covering. We put it above the deck: vapour control layer, then PIR, then the membrane, so no part of the structure is left sitting cold. The alternative is a cold roof with the insulation between the joists, which leaves the boards under the dew point and lets interstitial condensation build inside the construction. Against a thick stone wall that junction wants detailing rather than stuffing full of board. Building control are notified and inspect it open.

Junctions and openings. On a modern wall the abutment takes a chase with a lead cover flashing dressed into it and a cavity tray above. On old stone we step the flashing into the joints instead. Parapets take a coping with an apron below. Anything breaking through the covering is raised on a kerb first, so the membrane can turn up an upstand: a rooflight, a lantern, a Velux style flat roof window, a hatch, a soil and vent pipe. The open edges run out over a drip trim, and the rainwater outlet feeds a hopper, a downpipe or the gutter. A garage is a day, a back addition two or three working days.

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 stone cottage with a small flat over a back addition, a garage on a modern plot and a rear extension behind a terrace are three different jobs before anything is unloaded. 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.

West Lulworth sits in a bowl, and the ground rises on almost every side. That does something to flat roofs that no other village we work in does. A back addition roof, a garage or a flat extension that would be completely hidden anywhere else is in plain view from the paths above, and it is seen from the top down, which is exactly the angle a flat roof cannot hide from.

Inside the conservation area, appearance is what is controlled, so this stops being an aesthetic point and becomes a practical one. A bright white fibreglass roof or a light grey membrane reads as a pale rectangle from the hill, where a mineral finish or a darker covering disappears. Rooflights and lanterns are the other giveaway, because they add something that was not there. None of it prevents you having a modern, long lasting roof. It just means we agree the finish and the detail before the work rather than after, and put what was agreed on the written quote so there are no surprises for anyone.

We cover West Lulworth, East Lulworth, Winfrith Newburgh, Wool and the rest of BH20. 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.