Flat Roofing in Woodlands

Start on the surface. Leaf mulch and moss hold damp against a covering right through the winter, and a covering that never fully dries ages at twice the rate. On felt that shows as the mineral cap sheet going bald in patches, then the bitumen underneath hardening and cracking. On rubber it shows as a green film you can slip on. We brush it off, but if the trees are staying then the roof wants a surface that copes with being brushed: three layer built up felt takes boots and a stiff broom better than anything, and EPDM, a single bonded sheet with no flame used anywhere near old timber, is the easiest thing to keep clean.

Then the fall. Water that cannot run does not evaporate, it sits, and sitting water is what works into a lap and lifts it. Where a roof ponds we take the boarding up and re-cut the fall with firrings, or lay tapered insulation to the same effect, and we aim it at the outlet rather than at the corner where somebody has since built a garden room against the wall.

Then the outlet itself, which out here is the part that matters most. A standard domestic outlet is not much wider than a fist and one season of leaves will close it. We fit a guard over it, and where there is room we enlarge it or add a second, so that a blockage becomes an inconvenience instead of a flood. An overflow through the parapet or the fascia costs almost nothing to put in while the covering is off, and it will tell you something is wrong before your ceiling does.

Then the hopper, the gutter and the downpipe, which carry the water away and are the parts nobody has touched in years on an outbuilding or a garden room. They get cleared, re-fixed and checked for falls of their own. Approved Document H is the standard for rainwater drainage if you want to read what it should be doing.

Only after all of that, the roof build. Under the covering is a deck, and chipboard boarding that has spent years damp has nothing left to save, so it comes out and OSB goes back over joists we have checked while the boards are up. Above or below that deck sits the insulation. If we are stripping anyway we would rather build it warm, with PIR laid over the boarding and the vapour control layer beneath it, so the dew point sits above the timber. Cold roofs, insulated between the joists, depend on a clear ventilated gap, and under trees those gaps block. BS 6229 covers the construction.

The last hour is the detailing, and it is the hour that keeps you dry. A cover flashing chased into the wall, or lead dressed over an apron, where an addition meets the house. A drip trim along every open edge. Coping re-bedded on a parapet with a cavity tray behind it. A kerb built up under any rooflight or lantern so the skylight stands proud of standing water, and a collar on each Velux, hatch, soil pipe and vent pipe. GRP, brushed on wet over new ply and cured as one fibreglass skin, forms its own trims and is a tidy answer on a garden room with a lot of corners. Welded single ply is what we would put over a workshop span. Blisters, bubbles, splits and lifted seams in any of them are repairs: back to sound material, a new piece bonded or welded across, edge dressed down.

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 under trees, a garden room at the end of a plot and a flat roof over a rear kitchen 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 Woodlands, Netley Marsh, Ashurst, Bartley and Cadnam across SO40, working over 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.