What is RAAC Concrete? The Dangers of Reinforced Autoclaved Aerated Concrete

RAAC - Reinforced Autoclaved Aerated Concrete

During the post-war building boom of the 1950s, 60s, and 70s, Reinforced Autoclaved Aerated Concrete (RAAC) was hailed as a wonder material. Lightweight and versatile, RAAC was utilised extensively to craft pre-formed concrete components, revolutionising the construction of public buildings during that era.

However, as the decades passed, a dark secret emerged – the structural strength of RAAC did not stand the test of time. Its porous, sponge-like nature, especially when used in roofs, allowed it to absorb moisture, weakening the material and corroding the steel reinforcement within. Consequently, RAAC began to sag, leading to water pooling on roofs, exacerbating the problem. The material that was once celebrated in the 1950s was at risk of failure by the 1980s.

Shocking revelations indicated that the lifespan of RAAC in many public buildings, including hospitals and schools, was no greater than 30 years. Yet, the urgency to address this issue seemed lacking.

In 2018, a wake-up call occurred when the roof of a primary school in Gravesend, Kent suddenly collapsed, thankfully on a weekend, without injuring anyone. Investigation into the collapse unveiled that the RAAC planks used in the roof had significantly weakened with age. The steel reinforcement inside didn’t extend all the way to the ends where it was supported by the walls. It was a clear indication that not only was there a problem with the material itself, but also with construction practices.

In response, the government initiated efforts to identify schools and hospitals at structural risk due to RAAC. While the 104 schools at the greatest risk represent only a small fraction of the 22,000 state-owned educational institutions in England, this issue has posed significant challenges for the academic year’s start.

Amidst this backdrop of growing concerns over RAAC, there’s a glimmer of hope. Enter the world of 3D laser scanning, a technological marvel that promises precise analysis and expert solutions to address RAAC-related problems.

Expert 3D Laser Scanning Solutions by PointSCAN

PointSCAN, a leading provider of 3D laser scanning services, has taken center stage in addressing RAAC-related challenges. Their extensive experience in dealing with RAAC issues on various sites has equipped them with valuable insights into the complexities of this material.

One of PointSCAN’s key approaches in dealing with RAAC is deviation analysis. This sophisticated technique goes beyond conventional measurements by comparing the as-built condition of RAAC structures with their intended design. Through deviation analysis, PointSCAN can pinpoint even the slightest deviations or anomalies in the structure.

Deviation analysis is a meticulous examination that enables PointSCAN to identify where RAAC may be weakening, where moisture infiltration is occurring, or where structural integrity is compromised. It’s a process that hinges on the precision and accuracy of 3D laser scanning technology.

RAAC - Reinforced Autoclaved Aerated Concrete 3D Laser Survey

Data-Driven Insights for Precise Solutions

The insights gained from deviation analysis are invaluable. They don’t just allow PointSCAN to diagnose RAAC issues accurately; they provide the foundation for crafting precise and tailored solutions. This data-driven approach ensures that any necessary repairs or reinforcement measures are targeted exactly where they are needed, saving time and resources while enhancing safety.

PointSCAN’s commitment to utilising technology and data for solving RAAC challenges underscores their dedication to delivering the highest standards of service. They don’t just scan; they analyse, interpret, and provide actionable recommendations based on the most accurate data available.

When it comes to addressing the dangers of Reinforced Autoclaved Aerated Concrete, PointSCAN’s combination of experience, 3D laser scanning, and deviation analysis sets them apart as a trusted partner in ensuring the structural integrity of RAAC structures.


The hidden dangers of Reinforced Autoclaved Aerated Concrete (RAAC) are a serious concern, as highlighted by recent incidents. However, with the precision and expertise offered by PointSCAN, there is hope for addressing these challenges effectively. PointSCAN remains committed to providing accurate data and data-driven insights to ensure the safety and longevity of structures affected by RAAC. Together, we can uncover and overcome the hidden dangers posed by this material, making our buildings safer and more resilient for the future.

Don’t hesitate to reach out to us for help with your RAAC-related challenges. Our services encompass a wide range of solutions, including 3D laser scanning, measured building surveys, concrete analyses, and much more. Get in touch with us using the button below.