Flat roofing in Holton Heath

Garages, canopies and the room across the back. Around Holton Heath the flat roofs are attached rather than main roofs: an integral or detached garage, a canopy over a front door, a utility or dining room built across the back, and the odd flat topped dormer.

Most in Holton Heath are torch on felt or a built up three layer system finished with a mineral cap sheet, with some GRP fibreglass on the newer ones. We lift a corner and look at the deck, because everything else follows from it. Plywood and OSB that has stayed dry can be re-covered. Chipboard decking that has been wet loses its strength and sags between the joists, so it comes off and new boards go on before any membrane.

Getting the water off. Ponding is the fault behind most flat roof leaks. Water that stays put pushes into every lap and seam and a frost then splits them. The usual causes are a fall that was never built in, firrings cut too shallow, tapered insulation crushed by foot traffic, or a rainwater outlet choked with grit and moss. We rebuild the falls so the roof drains at an outlet instead of in the middle, which is what BS 6229:2025 on flat roofs expects, then run water through and watch the gutter, hopper and downpipe take it.

Trims, upstands and seams. Very little goes wrong in the middle of a covering. The trouble is at the edge trim, the drip, the apron flashing where the roof meets the house, the kerb round an opening, and the laps. Felt gives you a blister, a bubble or a split. Single ply lifts at a failed seam. Fibreglass cracks where a sharp internal angle has been flexing. Everything soft comes out. The upstand is rebuilt to a height that will genuinely hold water back, and the seams are welded or bonded rather than taped over and hoped about.

Openings, abutments and the build up. A rooflight, a lantern, a Velux, an access hatch or a soil and vent pipe gets a kerb and a collar rather than a ring of mastic. Where the flat butts brickwork a lead cover flashing is chased into the wall, and on a parapet the coping and the tray behind it are checked. Older Holton Heath roofs of this kind are cold roofs, insulation between the joists and a still void above, and that void is where condensation gathers and interstitial damp rots the deck without anything showing on top. A warm roof cures it. Insulation goes down on top of the deck, the vapour control layer goes beneath the insulation, and no ventilated void is left to go stale.

The area is the easy part to measure. What decides the price is the state of what sits under the covering, and you only find that out by looking.

Which roof it is. A detached garage at the end of a drive can be done off a tower. A rear extension against a two storey wall wants a scaffold that stays up while the deck is open. A dormer on a chalet bungalow is small but awkward, with upstands against tiles on three sides. The work at height rules mean the platform is priced as its own line.

The deck. Holton Heath roofs from the eighties were often decked in chipboard. Kept dry, it is fine to re-cover. Wet for a few winters, it goes soft and has to come off. Thomas lifts a corner before quoting because this is the biggest swing in the price.

The falls. Many older garage roofs were laid almost flat and now pond. Correcting the fall with firrings takes longer than laying the membrane, but it is what makes the new roof last, and the British Standard for flat roofs sets out how a fall should work.

The edges. Upstands, edge trims and each outlet are priced one by one, because that is where both the labour and the leaks are.

Ask every quote which system and how many layers, whether the deck is being replaced or covered over, whether firrings are included, and whether the scaffold and the skip are in the figure.

A lot of the housing around Holton Heath went up in the nineteen eighties, and that tells you something useful about the flat roofs. They were built as cold roofs, with a thin layer of insulation between the joists, a chipboard deck and a three layer felt covering on a shallow fall.

Those materials had a good run and they are all reaching the same point at roughly the same time, which is why one road in Holton Heath often has several garage and extension roofs failing within a year or two of each other.

What that means for you is that a straight like for like re-cover is usually the wrong answer. If the deck is going anyway, the sensible move is to rebuild it as a warm roof, with the insulation above the deck instead of between the joists and the falls corrected while the boards are off. It costs a little more in insulation and firrings than putting felt back on tired chipboard, and it deals with the condensation problem that comes with a cold roof rather than passing it on to the next owner.

We come out from our base in Boscombe, 10.7 miles away, to Holton Heath and the neighbouring parts of BH16, including Sandford, Organford, Lytchett Minster and the roads towards Wareham, with Dorset Council as the planning and building control authority.

You deal with Bournemouth Roofing & Building Ltd, registered in England and Wales, company number 15471719. The firm's owner, Thomas Hannen, visits, gets up on the roof and writes the price himself. On Checkatrade, a verified customer has rated us 10 out of 10. The site visit is free, and the written quote, itemised line by line, costs nothing either. Before you book a visit in Holton Heath, you can read our customers' Google reviews, word for word, on our reviews page.

Most repairs in Holton Heath need no application at all. What decides whether a change to the outside of your house does is who the council is, whether a conservation area or a listing applies, and whether the place sits in a protected landscape.