What to do if you suspect RAAC in your building

What to do if you suspect RAAC in your building

What to do if you suspect RAAC in your building

Turn on any news channel and you’ll see stories of public sector buildings constructed with RAAC being deemed unsafe for use. It’s proven a huge problem for the UK government, particularly when it comes to needing to close schools to inspect and make any necessary repairs. But how commonly was RAAC used as a building material? And should you worry if you suspect it in your building?

About RAAC

RAAC stands for Reinforced Autoclaved Aerated Concrete. It was primarily used in construction from the mid-1950s to the mid-1990s, to create prefabricated roof, floor and wall panels.

It differs from normal concrete because it is made without aggregate and has air voids, giving it a ‘bubbly’ texture. The material is lighter than traditional concrete, meaning the panels could be transported to site and lifted into place much more easily and quickly, shortening construction time.

The downside of the material is that the voids allow water to easily enter the panels, causing reinforcement bars to rust and spalling of concrete, causing weakness to the structure.

As flat roofs are most susceptible to water ingress, the majority of structural issues have been related to RAAC roof panels. Buildings constructed with RAAC therefore require regular proactive maintenance, with in-depth monitoring of the panels and their condition. Without it, serious structural problems can occur and in some cases, catastrophic collapse, which sadly occurred at a school in Kent in 2018.

How to recognise if your building has RAAC

As highlighted above, construction with RAAC was prolific from the mid-1950s to the mid-1990s. If your building dates between this time, it’s worth getting it checked by a structural engineer to determine if the material was used, especially as it has been determined that RAAC planks have an estimated life span of 30 years.

Other telltale signs are if your building has a flat roof as this was the most common approach to using the material at the time, and if the roof/floor feels solid, unlike timber which can feel bouncy or sound hollow. However, we would recommend advice is taken from a qualified structural engineer or surveyor to determine if RAAC is present in your building.

Determining the amount of damage and risk

If RAAC has been found in your building, a structural engineer can determine any damage and risk by looking for concrete cracking, spalling, and the amount of panel that is supported off the structure. Get in touch with an experienced professional as soon as possible if you notice signs of cracking or spalling to concrete.

The fact that the material holds water can make damage difficult to notice by eye. In some cases, internal reinforcement has been rusting without concrete spalling which adds to the complexity of the assessment. Measurements should therefore be taken of how much the panels are deflecting.

How much does a RAAC survey cost?

Our experienced structural engineers at AWA will be able to determine whether RAAC is present in your building.

A thorough survey will be carried out and a report provided to state if there is RAAC in the building. If it is present, the next steps will be set out in the report. We are here to support you if subsequent work is required.

Survey fees are dependent on the size and complexity of the building, as well as the distance to travel from our offices in Romsey and Bath. Get in touch on 01794 524447 for a quote.

Why choose AWA Engineers

AWA is a structural engineering and civil engineering consultancy established in 1987, with a hard-won but deserved reputation for delivering excellence in our profession.

Our philosophy is simple: we put people first. This has resulted in a high number of repeat clients and an impressive track record of successful award-winning projects. We are proud to be professional, and approachable; we believe this makes us the ideal partner for your project.

AWA has chartered engineers in our offices located in Romsey, Hampshire and Bath, Somerset. We deliver services to clients across the South, South East and South West.

Our team includes both chartered structural engineers and chartered civil engineers committed to continuous professional development ensuring you benefit from up to date industry expertise, whatever your project entails.

Contact us today

To find out more about how AWA can help with your project, get in touch today. Call 01794 524447 (Romsey) or 01225 251498 (Bath)  to speak to a member of our team. Alternatively, email and one of the team will be in touch.

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