RAAC

What should you do if a concrete soffit is stained or cracked and the survey mentions RAAC?

Treat staining and cracking as reasons for the structural assessment, not as a DIY diagnosis. IStructE’s guidance exists because the condition of RAAC panels, including how they are performing, is an engineer’s judgement. A stain also means water has been getting in, which is a covering failure whether or not the plank is RAAC. Stop the guesswork and separate the two questions.

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?

Water sitting on a panel is part of why roofs of this kind worry engineers. The home survey can see a brown mark and a crack. It cannot measure deflection or see the reinforcement. The next person is the chartered or incorporated structural engineer IStructE names, with access to the soffit and, if needed, the roof. A roofer may still be needed for the waterproofing, after the deck is understood.

Do not screw into the soffit, do not scrape it, and do not cover the crack with lining paper before the engineer has seen it. Tell the seller access is needed. If they refuse, you are back to a decision about proceeding without an assessment. There is no honest budget on this page for “RAAC repairs”. The assessment says what, if anything, is required.

What should you ask your surveyor?

Where is the staining, and is the soffit deflecting as well as cracked?
Could you see the panel bearings?
Are you separating the waterproofing from the plank?

What are the typical next steps?

Photograph the soffit. Do not drill it.
Instruct a structural engineer if RAAC is suspected. Show them the stains.
Do not let a felt contractor overlay the roof until the engineer has said the deck can stay.

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

Is a stain alone proof of RAAC failure?

No. It is proof of water. The panel type and its condition are the engineer’s job. A timber deck can stain too.

Should you leave the flat empty?

If an engineer or the surveyor says there is an immediate safety concern, follow that advice and tell the freeholder. This page cannot judge a soffit it has not seen.