Do You Need an Asbestos Survey Before Re-Roofing?

On this the HSE is blunt: for any building built or refurbished before 2000 it advises assuming asbestos is present. The assumption stands until someone competent has checked. That includes houses from the post-war decades, which were put up when asbestos products were in everyday use, and it includes later houses that had work done before 2000.

It does not mean every house is full of it, or that the material is dangerous while it sits undisturbed. The risk comes from breaking, drilling, sanding or crushing it, which releases fibres. A re-roof is exactly the kind of job that does this, because it strips off old coverings, pulls out nails and boards and pushes debris about.

That is why the question comes up before the work, not during it. A roofer who finds a suspect board halfway through a strip-out has to stop, and you face delay and extra cost. A roofer who asked at the start can plan around it. Our guide to re-roofing and the Building Regulations covers the other paperwork to check before a roof comes off.

On a domestic roof the likely places are the ones attached to the roof edge and the roof itself. Corrugated or flat roof sheeting on garages, porches and extensions was often asbestos cement. Among its examples of insulating board locations the HSE names external soffits, and it adds that such boards look much like asbestos-free ones, so the eye cannot settle it. Our answer on asbestos soffit boards goes further.

Other parts worth having checked on an older roof are flue and vent pipes, rainwater goods and old felt or bituminous layers beneath the tiles. Whether a particular item contains asbestos cannot be told by looking, which is the whole reason for sampling and testing. A garage block roof is a common example, and our post on asbestos garage roofs explains what to look for.

Do not poke, scrape or drill a suspect sheet to see what it is. Leave it alone, keep children and pets away and have it assessed. Weathered asbestos cement can also be fragile, so never walk on it.

A survey made for work that will disturb the building is the right kind here. It is commonly called a refurbishment survey, and it looks at the parts of the building that will be affected, which in a re-roof means the roof, the roof edge and the loft. Samples go to a laboratory, and you receive a report listing what was found, where and what condition it is in.

Ask the surveyor what the report covers, and ask them to name the areas included. An asbestos surveyor carries out the testing. The survey is a separate piece of work from a separate specialist, and it is better arranged before the quote than after the scaffold is up.

Be wary of a roofer who says there is nothing to worry about without any basis, and equally wary of one who says asbestos is certain without any testing. Both are guesses. A written survey replaces the guess with a record, and it protects everyone who goes on the roof, including later tradespeople. We recommend it for any pre-2000 house where the roof is to be stripped, and we will explain what the report means for the job.

It is not always a disaster. The HSE classes careful removal of intact asbestos cement, roof sheeting for example, as non-licensed work, and weathering alone does not change that. Once a sheet is badly damaged or broken up, tighter rules apply, and the HSE warns that a roof of this type is fragile at all times.

Insulating board, which is where soffits come in, is different: most removal of that material is licensed work, so never assume that anything on the roofline counts as the simpler type. The result is that the right route depends on what the survey says. Asbestos waste is bagged in two layers, marked as such and kept apart from household rubbish.

You may be asked to arrange a specialist contractor for removal and then have the re-roof done afterwards, or the sequence may be agreed between the two firms. Either way, the cost is in addition to the roof. Our own price comes as a single written total, with pictures from the roof inspection so that you can follow the proposal. See also the wider page on roof replacement.