RAAC

The flat roof deck is described as planks that may be RAAC, and no core was taken. What investigation has the survey deferred?

The survey has deferred any investigation that would identify the planks. The flat roof deck is described as planks that may be RAAC, and no core was taken. RAAC is a form of concrete panel that IStructE says needs investigation. This visit has not investigated the deck and has not sampled a plank. It has recorded a possible identification from what could be seen, and it has left the actual investigation, including any opening-up or testing, to a later specialist instruction. The word may is doing real work in that sentence.

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?

A flat roof seen from below, or from a hatch, can show the soffit of a plank, a joint, or a span. Those clues can be enough for a surveyor to warn that the deck might be this form of panel. They are not a core, a laboratory result, or the assessment IStructE describes. The report should stay at possible RAAC and at the fact that no sample was removed. Do not let a description harden into a confirmed diagnosis or a claim that the plank was proved harmless.

If you proceed, the next paper is an investigation by someone competent to assess this type of panel, with access agreed and with no pretence that the home survey already did it. Tell the solicitor and any lender that the deck is unconfirmed and unsampled. Do not ask the surveyor to delete the warning because no core was taken. The missing core is the reason the warning stays provisional. The survey has pointed at the deck and stopped.

What should you ask your surveyor?

What did you actually see of the flat-roof planks, and from where?
Have you stated that no core was taken and no investigation was done?
Which further instruction are you deferring rather than completing yourself?

What are the typical next steps?

Keep the deck as possible RAAC, not as a confirmed panel.
Do not treat the home survey as an investigation or a sample.
Commission a proper investigation if this roof needs a decision.

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

If the ceiling is boarded, can the planks still be named with certainty?

No. A boarded ceiling hides the deck. The survey's may is already a limit. Boarding makes the identification less direct, and it certainly does not replace the core that was not taken from the deck. No core was taken here.

Does a recent felt recover identify the planks underneath?

No. New felt is a covering. It does not sample the deck and it does not investigate whether the planks are RAAC. The survey has still deferred that question and has not sampled a plank. The felt is not a core.