RAAC identification and assessment
An inspection to identify reinforced autoclaved aerated concrete (RAAC) and assess its condition and risk, in line with current industry guidance.
About this service
Reinforced autoclaved aerated concrete, usually shortened to RAAC, is a lightweight precast material used mainly for roof planks, and sometimes floors and walls, from the 1950s into the 1990s. It is much weaker than ordinary reinforced concrete and copes poorly with water. Planks that have been wet for years, were cut on site or have short bearings can deflect, crack and in some cases fail with little warning.
Most publicity has focused on schools and hospitals, but RAAC also turns up in residential property: flat roofs on low-rise blocks, garages, extensions, community buildings converted to homes and commercial units beneath flats. Owners, landlords and buyers increasingly face questions about it from lenders and insurers. Our RAAC guide for property owners explains the background in more detail.
Our assessment follows current industry guidance. We first establish whether RAAC is present, then assess the condition of any panels found and give each area a risk rating with clear recommendations, from routine monitoring through to propping or replacement. Every RAAC report is signed off by a chartered engineer who is a Member of the Institution of Civil Engineers (MICE).
When you need it
- Your building was constructed or altered between the 1950s and 1990s
- A landlord, school, insurer or lender has asked about RAAC
- You need to know whether planks need monitoring, propping or replacement
What's included
- Review of available drawings and records
- Inspection of roofs, floors and walls for RAAC
- Condition assessment of any panels found
- Risk rating and recommendations
How it works
- Review recordsWe check original drawings, specifications and maintenance records where they exist. The construction date and building type help narrow down where RAAC is most likely to have been used.
- Inspect for RAACWe examine roofs, floors and walls from below and, where safe, from above. RAAC has a bubbly texture with no coarse stones, and we may lift ceiling tiles or open small areas to confirm.
- Assess conditionPanels found are checked for sagging, cracking, water staining, corroded reinforcement, bearing length and evidence of cutting or later alterations. These are the factors that drive the level of risk.
- Rate and recommendEach area gets a risk rating with recommended actions and timescales. If we find anything urgent, we tell you on the day so steps such as restricting access or propping can follow.
What you receive
What happens if RAAC is found in your building?
Finding RAAC does not automatically mean the roof must come off. Panels in good condition, kept dry and properly supported, can often stay in place with regular monitoring. The decision depends on what the inspection shows, with the main concerns being long-term water ingress, visible sagging, cracks running across the panel and bearings that are short or damaged.
Higher-risk panels may need temporary propping while a permanent solution is designed, which could be strengthening, extra support beams or full replacement. If a flat roof is due for re-covering anyway, that is often a sensible moment to replace RAAC planks altogether. Where remedial work is needed, our remedial works design service takes the project forward to Building Control approval.
Frequently asked questions
How do I know if my building has RAAC?
Look for flat roofs, floors or walls built between the 1950s and 1990s using lightweight concrete panels. Exposed RAAC is usually grey or white, with a bubbly, aerated look and no visible stones. It is often hidden behind ceilings and finishes, so an inspection by an engineer is the reliable way to confirm whether it is there.
Is RAAC dangerous?
RAAC is not inherently dangerous, but it is less robust than conventional concrete and can deteriorate, particularly after long-term wetting. Panels in poor condition can sag or crack and, in some cases, fail suddenly. The level of risk depends on condition, which is why a proper assessment followed by monitoring or remedial work is what matters.
Can I get a mortgage on a property with RAAC?
Some lenders will not lend where RAAC has been identified without further information, while others accept it alongside a satisfactory engineer's report. Lender policies change, so check with your lender or broker. A clear assessment showing condition, risk rating and any remedial work gives them the evidence they usually ask for.
How much does a RAAC inspection cost?
Our RAAC identification and assessment starts from £600 + VAT for a typical residential building. Larger buildings, roofs with limited access or the need to open up finishes increase the fee. We confirm a fixed fee in writing before visiting, and our typical turnaround is 10 working days.