RAAC Survey & Removal

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RAAC, or Reinforced Autoclaved Aerated Concrete, is a unique concrete. It’s made differently from the usual heavy concrete we see.
Think of RAAC like a honeycomb. It’s lightweight because of the tiny air pockets created by gases during its making.
These concrete slabs then undergo a special heating process to make them stronger.
It was a cheap way to make building material that is light, good at keeping heat in, and resistant to fire. However, it’s not as sturdy as regular concrete and can break or fail over time.

It’s common in public buildings, especially schools and colleges built between the 1950s and 1990s.
RAAC has been used for various parts of buildings like roofs, floors, walls, and designs near the roof.

In 2022, the government warned that RAAC is old and might fall down.
Some issues with RAAC were even covered on ITV News, highlighting problems in a UK school.

RAAC has a unique look. If you break it, it will look like a honeycomb. It feels rough and might have holes you can see.
It’s often shaped into planks with angled edges, making it easy to spot.
Before, people thought they could see when RAAC was going bad. But now, we know that sometimes these structures can fail suddenly.
Professor Goodier says many buildings, especially those from the 1960s and 70s, have these RAAC panels. Many of them are showing signs of age and damage. Since a lot of them are used on flat roofs, it’s hard to check, maintain, or replace them.