For a RAAC survey in Stanwell, NDTScan brings something no general scanning contractor can: hands-on experience of identifying and analysing reinforced autoclaved aerated concrete across the UK, in schools, hospitals, housing, public buildings and commercial estates. Surrey has its share of the roofs and floors built with these planks between the late 1950s and the mid 1990s, and most have never been properly surveyed.
The Department for Education's list of education settings with confirmed RAAC, published in February 2024, includes 7 settings in Surrey, among them Pewley Down Infant School, Kings College Guildford and The Grove Primary Academy. The Department of Health and Social Care's list of hospital sites with confirmed RAAC includes Guildford Hospital and Frimley Park Hospital in Surrey. NDTScan cites the published lists as evidence that RAAC is in the Surrey building stock, and for no other reason. Education and health estates were counted because government asked for them to be counted. The equivalent stock in Stanwell's council, housing, leisure, retail and commercial buildings has not been, and that is where most uninspected RAAC now sits.
A RAAC survey from NDTScan starts with identification. Ground penetrating radar separates aerated planks from dense concrete, hollowcore and timber decks plank by plank, and the reinforcement pattern, transverse bars and plank widths confirm the reading without opening the roof. Condition comes next: cracking, deflection, end bearing, water staining, corrosion and previous repairs are recorded for each plank, and the findings are classified in line with IStructE guidance so the Stanwell owner can see at once which elements need action, which need monitoring and which are sound.
The most expensive mistake in Stanwell, as everywhere else, is to act on RAAC before it has been understood. Whole buildings have been closed on the strength of a visual inspection that could not tell RAAC from hollowcore. NDTScan's position is that identification and condition assessment come first, remediation second, and the report has to be good enough to design from.
Scan before you repair. That is the standing advice for every Stanwell client, and the reason NDTScan reports what the concrete contains before anyone specifies what to do about it.
Services Available in Stanwell
- RAAC Identification Survey GPR based, plank by plank identification of reinforced autoclaved aerated concrete in roofs, floors and walls across Stanwell. Confirms what the element is made of without opening it up, and records plank widths, reinforcement and bearing details as evidence.
- RAAC Condition Assessment Plank level inspection of confirmed RAAC for cracking, deflection, bearing length, water ingress, corrosion and previous repairs, classified in line with IStructE guidance. Reported so a Surrey engineer or estates team can act on it directly.
- RAAC Management and Reinspection Monitoring regimes, reinspection intervals and management plans for RAAC that is being kept in service, plus expert input where a Stanwell owner needs an independent second opinion on a survey or a remediation proposal.
RAAC in and around Stanwell
Around Stanwell the work divides into four kinds. Owners who do not know what their roof is made of and need it identified. Owners who know it is RAAC and need every plank assessed and classified in line with IStructE guidance. Estates teams who need a management plan and a reinspection regime for planks staying in service. And Surrey clients who have a survey or a remediation proposal in front of them and want NDTScan's independent view before committing money. Public bodies, housing providers, insurers and private owners all instruct on the same basis.
NDTScan also provides RAAC surveys in Guildford, Woking, West Molesey, Camberley, Epsom and New Haw, West Byfleet and Sheerwater and the rest of Surrey. The rest of the region is covered from the South East RAAC surveys page, and the service itself is described on the RAAC surveys page.
About NDTScan
NDTScan is a specialist non-destructive testing company based in Oxford and led by Neil Smuts, author of The RAAC Book. It is the UK's specialist in the identification and analysis of reinforced autoclaved aerated concrete, and a Level 4 UKCSS Operator, the first in the UK to achieve that certification. RAAC surveys in Stanwell sit alongside the company's concrete scanning and structural condition survey work, and every report is written to a standard suitable for engineering acceptance, insurers and dispute work.