EPDM rubber roofs

Plenty of garages, sheds, dormers and small extensions have a flat roof. Sooner or later the covering wears out and needs replacing.

Many people choose a single sheet of EPDM rubber for the new covering. Some fit it themselves and some hire a roofer. A few checks before the work starts make either route safer.

What EPDM is

EPDM stands for ethylene propylene diene monomer. It is a synthetic rubber. It stands up well to heat, sunlight, ozone and weather, and it can last outdoors for many years. Besides roofs, it goes into weather seals, garden hoses and waterproof linings.

EPDM breaks down when it touches bitumen-based materials. If the old covering is bitumen felt, ask the membrane's maker how to deal with it.

Building regulations

Replacing a roof covering usually needs building regulations approval. GOV.UK lists new coverings on pitched and flat roofs as work that may need it. Some small repairs to a flat roof do not.

A roof counts as a thermal element, which means the rules on keeping heat in apply to it. When a flat roof with built-in insulation is replaced, the owner may need to improve that insulation.

A roofer registered with a competent person scheme can certify the work, so the owner does not need to apply separately. Without approval, a homeowner may lack the certificates a buyer asks for when the home is sold. Your local building control team can say whether your project needs approval.

Working safely on a roof

The Health and Safety Executive (HSE) calls all roof work highly dangerous, even work that takes a few minutes. Almost one in five deaths in construction work involve roofs. Most come from falls off an edge, or through a fragile roof or rooflight.

HSE's advice for builders is a secure double guardrail and toeboard around a flat roof's edge. It also says to treat every roof as fragile until a competent person has confirmed otherwise. A sheeted roof may not take a person's weight, whatever it is made of.

Older garage roofs and asbestos

Asbestos was used in many buildings until it was banned in 1999. Any home or garage built or refurbished before 2000 may contain some. Asbestos cement roof sheets are one of the places it turns up.

HSE advises against repairing or removing asbestos yourself without training. It also says material in good condition is often better left where it is. Your council's environmental health team can give advice, and any builder should be told about asbestos before they start.

Choosing a roofer

The National Federation of Roofing Contractors (NFRC) is the UK's largest roofing trade association. Its members are inspected before they join and every three years after that. They must also hold employers' and public liability insurance.