RAAC

The garage roof looks like concrete planks and the house roof is timber. Why must the garage suspicion not be copied onto the house as a RAAC finding?

Not a finding about the house. A garage roof that looks like concrete planks must not be copied onto the timber house roof as a RAAC finding. The suspicion, if it is even fair, belongs to the garage. The house roof is timber, which is a different construction. RAAC is a particular concrete panel, identified by investigation, not a label you transfer between roofs because they share a postcode. Write the garage as the thing that looked like planks. Do not write the house as RAAC when its roof is timber and was not that suspicion.

Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.

What is the fuller explanation?

Concrete planks are not automatically reinforced autoclaved aerated concrete. Many garages have ordinary concrete sheets or slabs. IStructE's guidance is about investigating and assessing RAAC panels, which a home survey does not complete by eye from the drive. Even a genuine garage suspicion would still be about the garage. Copying it onto the house invents a second building. The timber roof needs its own note: what was seen in that roof, not a borrowed concrete label.

Keep the sentences apart in the report and in anything you send a lender. One sentence for the garage planks, including that they were not confirmed as RAAC. Another for the house roof, saying it is timber. Do not let an agent merge them into a line that the property has RAAC. If the garage needs a specialist look, that look is of the garage. The home survey has not identified RAAC in the house by suspecting the garage.

What should you ask your surveyor?

Which roof looked like concrete planks, the garage or the house?
What did you actually see of the house roof structure?
Have you named RAAC anywhere the material was not investigated?

What are the typical next steps?

Keep any plank suspicion on the garage alone.
Describe the house roof as the timber construction that was seen.
Do not tell a lender the house has RAAC because the garage looked like planks.

Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.

Also asked about this

Are concrete garage planks always RAAC?

No. Planks are not a RAAC identification. They must not be copied onto a timber house roof as one, because the house roof is a different construction.

If a specialist later checks the garage, does that check the house?

No. A garage investigation is not a finding about a timber house roof, and it does not rename the house as RAAC.