Flat roofing in Matchams

Garages, workshops and stores. The bread and butter here, and usually the largest flat roofs on the plot. Most are a three layer built up felt under a mineral cap sheet that has weathered and split at an edge. If the deck is dry we strip and re-lay: EPDM rubber for a plain rectangle, GRP fibreglass where there are kerbs and detail, a modern torch on system on a big straightforward span, and single ply welded at the laps where the area is genuinely large.

Garden rooms and extensions. A lot of garden buildings out here were put up quickly, with a deck laid dead level and a covering turned over the edge with no trim. That gives you standing water in the middle and a lifted or failed seam at the corner within a few years. Put right, it means firrings to create a fall, a proper edge trim and drip, and upstands taken high enough where the roof meets a wall.

Debris, and why the outlet is the weak point. Pine litter does not wash through. It packs into a rainwater outlet, a hopper or a downpipe and stays there, and resin sets the mat solid, so the roof fills before anybody notices. A blocked outlet is behind more ponding on this stretch than bad falls are. We clear the outlet, run water through the downpipe to prove it, and fit a guard where it is the sort of roof that will do it again.

What is under the covering. Plywood, OSB or chipboard on joists. Chipboard that has been wet swells and stops holding a fixing, and it has to come off. Above the deck a warm roof takes PIR over a vapour control layer, so the timber never sits at the dew point. A cold roof puts the insulation between the joists and has to be ventilated properly, or condensation and interstitial damp ruin the decking without a leak ever happening. BS 6229 sets out both, and tapered insulation is how you fix a fall when you cannot raise the joists.

The details. Blisters and bubbles, a split or crack in a brittle covering, and the apron where a roof runs into a wall are the usual repairs. At an abutment the wall is chased out and lead is dressed down over the upstand rather than sealed with mastic, and a parapet gets its coping and cavity tray looked at. Openings mean a rooflight, a lantern or a Velux on a formed kerb, plus any soil pipe or vent pipe through the deck.

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 double garage on an open plot, a workshop at the bottom of a garden and a flat roofed extension on a heath edge bungalow are three different jobs, and only one is easy to get materials to. 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 Matchams, St Leonards, St Ives, Ashley Heath and the BH24 addresses out on the heath, with Dorset Council as the authority for anything notifiable. 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.