Roofing work: repairs, re-roofing and flat roofs

Concrete interlocking tiles are common on post-war British houses. Clay plain tiles and natural slate are common on older houses and last much longer, but the nails, battens and underlay beneath them often wear out first. When a roofer talks about nail fatigue on a slate roof, the slates themselves may be reusable while the fixings are not.

A good roofer explains whether the problem is local or general. Replacing a handful of tiles, rebedding or dry-fixing a ridge, or renewing lead flashings around a chimney are repairs. When the underlay has perished across the roof or battens are rotten, stripping and re-covering is usually the honest answer.

Built-up felt is the traditional flat roof covering, now usually modern torch-on or cold-applied systems in several layers. EPDM is a synthetic rubber membrane laid in one sheet, suitable for garages, dormers and extensions. GRP, or fibreglass, is laid wet and cures into a hard, jointless surface that can take light foot traffic. Liquid-applied coatings are also used for repairs and overlays.

Every system depends on the deck beneath it and on falls that drain water away. If the timber deck is soft or the roof holds puddles, a new membrane on top will not last. Replacing a flat roof with integral insulation can also trigger the requirement to improve its insulation.

According to the Planning Portal guidance for England, repairs or re-covering of a pitched or flat roof do not normally need a Building Control application if they affect less than half of the roof and less than a quarter of the whole building envelope. Beyond that, approval is needed, and because a roof is a thermal element, re-covering it should normally include improving its insulation.

Approval is also needed for structural alterations, a new covering that behaves differently in a fire, or a covering that is significantly heavier, for example replacing slate with concrete tiles, which may mean strengthening the roof timbers. A roofer registered with a competent person scheme for roof coverings, such as CompetentRoofer, can self-certify re-roofing without a separate Building Control application and gives you a certificate.

Re-roofing with a similar covering does not usually need planning permission, but a change of material in a conservation area or on a listed building can. Scotland has its own building standards, so check with your council there.

Roof work is work at height. The HSE points out that people die every year after falling while working at height, and roofs add fragile roof lights and old cement sheets that give way underfoot. The Health and Safety Executive expects scaffolding with guard rails and toe boards for most roof work on houses. This is not a DIY job, and a roofer who proposes to work off a ladder on anything more than a small repair is cutting a corner that matters.

Scaffolding on the pavement or road needs a licence from the council, which the scaffolding firm normally obtains. Ask who pays for it and how long the scaffold will stand.

Bats roost in roof spaces and under tiles and are protected by law. If they might be present, a bat survey may be needed before work starts, and a licence from Natural England or the equivalent body if bats are using the roof. Starting work first and finding out later can bring the job to a stop.

• repair or full re-roof, and which roof slopes are included
• covering, underlay, battens, ridge and verge system, flashings and valleys
• insulation upgrade and ventilation where required
• scaffolding, licence and skip, and how long they are needed
• how the work is certified under the Building Regulations
• guttering, fascias and soffits, and what happens to rotten timber found on stripping
• guarantee on materials and workmanship

Your request is free. You confirm your phone number by text message and your email by link, and roofers in your area see what needs doing, without your name or contact details. The first roofer to buy it pays Offrano, and the request is then closed to everyone else. Before that roofer receives your details, we email you its name, address and phone number.

We cannot promise that a roofer takes up every request; unsold requests are withdrawn after 21 days. You decide whether to accept the quote. Offrano checks that roofers who buy requests are registered businesses, not the quality of their roofs, so ask whether they belong to a competent person scheme and check it on the scheme's website.