RAAC (Reinforced Autoclaved Aerated Concrete) Testing Across the UK
Reinforced autoclaved aerated concrete (RAAC) has been widely used in roofs, floors and other structural elements, particularly in schools, healthcare buildings and public sector estates. As RAAC panels age, concerns about their long-term durability and potential for sudden failure have grown.
The Testing Lab PLC (TTL) works with clients and their structural engineers to provide RAAC testing and laboratory analysis, helping you understand the condition of RAAC elements and support decisions on management, mitigation and replacement.
RAAC testing and assessment across England, Scotland & Wales
We support organisations with RAAC issues in:
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Schools, colleges and universities
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Hospitals, healthcare and clinical buildings
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Local authority and central government estates
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Commercial, industrial and custodial buildings
Whether you are at the initial screening stage or dealing with known RAAC, we can design testing programmes from single buildings to large, multi-site portfolios.
What is RAAC (Reinforced Autoclaved Aerated Concrete)?
RAAC is a type of lightweight, aerated concrete manufactured as factory-made planks or panels with embedded reinforcement. It was widely used from the 1950s through to the 1990s, particularly for:
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Flat roofs and roof decks
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Some floors and wall panels
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Long-span, lightweight structural elements
Unlike traditional dense concrete, RAAC has a cellular, low-density structure, different strength and stiffness characteristics, and a different way of ageing and interacting with moisture and reinforcement.
Why RAAC is a concern
As RAAC elements age, several issues may arise, including:
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Loss of strength and stiffness over time
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Increased moisture ingress and corrosion of embedded reinforcement
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Cracking, deflection and localised deterioration
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In some cases, a risk of sudden, without-warning failure, especially where water ingress or overloading is present
This has led to increased scrutiny from government, regulators and professional bodies. Dutyholders are expected to identify whether RAAC is present, understand its condition and put in place appropriate management strategies where it is found.
To discuss RAAC testing, sample requirements or how laboratory analysis can support your RAAC strategy, please contact our experienced and dedicated team:
Tel: 0800 177 7264
Email: info@thetestinglab.eu
Or please complete our online call back form by clicking on the “Call Me” button, and we’ll respond promptly.
When should you arrange RAAC testing?
RAAC testing and analysis should be considered when:
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There is reasonable suspicion or confirmation that RAAC is present in roofs, floors or other structural elements
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Visual surveys by competent professionals have highlighted defects, moisture issues, cracking or concerns about condition
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You are planning major works, refurbishment or changes in use that may affect loading or exposure of RAAC elements
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You need objective data to support decisions on temporary propping, load restrictions, monitoring or replacement
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Regulators, insurers or governance bodies are asking for evidence-based assessment rather than assumptions
Testing should always be planned in conjunction with a competent structural engineer, who will interpret the results in the context of the overall structure and loading.
Our RAAC testing and sampling service
TTL PLC provides a laboratory-based RAAC testing service, working alongside building owners, surveyors and structural engineers. Typical steps include:
Typical RAAC tests we support
Depending on your objectives and the condition of the RAAC, the test schedule may include:
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Density and moisture content
To understand the basic physical properties and variability of the material. -
Compressive strength testing
To measure the strength of RAAC under load and compare against assumed or design values. -
Petrographic examination / microstructural assessment
To review the internal structure, cracking, voids and signs of deterioration. -
Reinforcement condition assessment (on extracted samples)
Visual and, where possible, measured assessment of embedded reinforcement, corrosion, cracking and cover. -
Carbonation depth testing (on appropriate samples)
To assess the depth of carbonation, which may be linked to reinforcement corrosion risk.
Additional or bespoke tests can be incorporated where needed, agreed with your structural engineer and specification requirements.
How RAAC test results are used
RAAC test results are normally interpreted by your appointed structural engineer and combined with:
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Visual survey findings
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Drawings and historical information
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Load assessments and usage patterns
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Monitoring data, where installed
They may be used to:
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Confirm or refine assumptions on RAAC strength and condition
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Prioritise RAAC elements or buildings for propping, monitoring or replacement
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Support decisions on temporary measures (e.g. access restrictions, load limits)
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Inform long-term asset management and capital investment plans
TTL’s role is to provide robust, traceable laboratory data that your professional advisers can rely on.
Who we work with
We provide RAAC testing support for:
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Local authorities and education providers
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NHS Trusts and healthcare organisations
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Central government bodies and agencies
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Commercial property owners and managing agents
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Structural engineering and surveying practices
We are comfortable working as a direct supplier to the asset owner or as a specialist laboratory sub-consultant within a wider professional team.
Why choose The Testing Lab PLC for RAAC testing?
Specialist laboratory expertise
Established testing provider with experience in concrete, geotechnical and building materials testing.
Integrated property risk services
Ability to combine RAAC testing with asbestos, Legionella, radon and geotechnical services, giving you a broader risk picture where needed.
Clear, engineer-friendly reporting
Data presented in a way that supports structural assessment and decision-making, not just raw numbers.
Independent. Nationwide.
Supporting clients across England, Scotland & Wales from our National Control Centre in Doncaster.
Flexible project support
From small-scale investigations to national portfolios, with test programmes tailored to your specific brief and risk profile.
Areas we cover
From our National Control Centre, we provide RAAC testing services and laboratory analysis for projects throughout:
- Yorkshire & Humberside
- North East & North West
- East Anglia & East Midlands
- London, South East & South West
- West Midlands, Scotland & Wales
Samples can be delivered by courier, haulier or coordinated collection, and we will work with your structural engineer and contractors to programme testing in line with site investigations and safety measures.
Frequently asked questions about RAAC testing
Our Accredited Testing Services
Dear The Testing Lab PLC,
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Your analyst, Lee, was very helpful and his suggestions and advice appreciated.
We would have no hesitation in recommending The Testing Lab and will be in touch soon with regards arrangements for a full asbestos survey for the rest of the site.
TTL have been working directly as my analyst for the last 12 months on a very complex asbestos removal scheme, they have achieved all of their KPI’s without fail and on a number of occasions surpassed their SLA in acting for us on planning issues associated with the demolition in regard to contamination which cannot be removed as part of the normal sequence of operation.
There reports are always issued within timescales and they have policed the reports by the Licensed asbestos contractor faultlessly sometimes in very difficult circumstances.
