RAAC surveys in Thrapston are carried out by NDTScan, the UK's specialist in the identification and analysis of reinforced autoclaved aerated concrete. The planks were installed in Northamptonshire buildings for nearly forty years, mainly in flat and shallow-pitched roofs, and they are now well beyond the design life their manufacturers assumed. Identifying them is the first step; understanding their condition is the one that matters.
The Department of Health and Social Care's list of hospital sites with confirmed RAAC includes Kettering General Hospital in Northamptonshire. Royal and Derngate has also been publicly reported as containing RAAC. Those are the buildings that made the published lists, which cover schools, colleges and NHS sites. They are named here as evidence that the construction is present in Northamptonshire, not as NDTScan projects. Around Thrapston the same roof and floor planks are in council buildings, housing, leisure centres, retail units and industrial sheds that nobody has counted.
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 Thrapston owner can see at once which elements need action, which need monitoring and which are sound.
The most expensive mistake in Thrapston, 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 Thrapston client, and the reason NDTScan reports what the concrete contains before anyone specifies what to do about it.
Services Available in Thrapston
- RAAC Identification Survey GPR based, plank by plank identification of reinforced autoclaved aerated concrete in roofs, floors and walls across Thrapston. 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 Northamptonshire 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 Thrapston owner needs an independent second opinion on a survey or a remediation proposal.
RAAC in and around Thrapston
Typical Thrapston instructions: RAAC identification in schools, halls, clinics and council buildings built between 1955 and 1995; plank by plank condition assessment of confirmed RAAC roofs and floors; risk classification in line with IStructE guidance to support decisions on closure, propping or continued use; reinspection and monitoring of managed RAAC; and independent review of surveys and remediation proposals for Northamptonshire owners and their insurers. NDTScan covers Thrapston from Oxford in the same way it covers the rest of England.
NDTScan also provides RAAC surveys in Northampton, Corby, Kettering, Wellingborough, Rushden and Daventry and the rest of Northamptonshire. The rest of the region is covered from the East Midlands 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 Thrapston 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.