Flat Roofing in Tolpuddle

The chase is the first problem. Textbook detailing says cut a chase into the brickwork and dress a cover flashing into it. In a soft handmade brick, or in rubble, cutting a chase can do more damage than the leak ever did. So we work with what is there instead: lead dressed over an apron and secured into a raked out bed joint, pointed back in a mortar that suits the wall rather than a hard cement that will take the face off it in the first frost.

Movement is the second. Old walls shift with the seasons and a rigid covering does not enjoy being told to shift with them. It is one reason EPDM does well here: a single sheet of rubber, bonded cold, no joints out in the field of the roof and enough give at the upstand to live with a wall that moves. GRP, brushed on wet over fresh plywood and cured as one fibreglass skin, is superb over a stable deck and unforgiving over one that flexes. We choose by the building rather than by what is easiest to fit.

Fire is the third, and it decides more than people realise. Torching a built up felt roof means an open flame against old timber, dry ivy in a wall, or thatch on the roof next door. Where that is the situation we will not torch it. Three layer built up felt is a fine covering and we still fit it, but it goes down cold bonded or self adhesive under the mineral cap sheet. Single ply, hot air welded at the laps, is another way round the same problem on a wider span.

Then the ordinary work, which is the same here as anywhere. The boarding comes up if it is soft, chipboard being the usual culprit, and OSB goes back over joists we have checked. The fall is re-cut with firrings or tapered insulation so water reaches an outlet instead of sitting in a hollow. Parapets, of which this village has plenty, get their coping re-bedded with a cavity tray behind. Every open edge takes a trim with a drip on it. Rooflights and lanterns go back onto kerbs we build up so the skylight stands clear of standing water, and Velux units, hatches, soil pipes and vent pipes each take a collar. The outlet, hopper, gutter and downpipe are cleared before we price a covering. Blisters, bubbles, splits and seams that have lifted are all repairable: back to sound material, a new piece bonded or welded in, edge dressed down.

Insulation is the one place where an old building wants some thought. A warm roof, with PIR over the deck and the vapour control layer beneath it, keeps the dew point out of the timber and is what building control will expect on a renewed covering. On a building with solid walls and no damp course, though, it is worth asking where the moisture in the fabric is going once you seal the top of it. BS 5250 covers moisture in buildings and Approved Document L the thermal standard. We would sooner have that conversation before the boards go down than after the plaster starts to bloom.

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 garage on a village plot, a flat roof over a rear kitchen and a porch on a cottage frontage are three different jobs before any covering 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 Tolpuddle, Puddletown, Affpuddle, Briantspuddle and Milborne St Andrew across DT2, working out 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.