Reinforced autoclaved aerated concrete (RAAC) in the news: How to protect your building.
What are concrete experts saying about the big media focus on RAAC? If you suspect this dangerous material might be in your building, here’s what you can do about it.
Used widely from the 1930s to the 1990s, RAAC was created with an intended lifespan of only about 30 years. Since 2018, sudden collapses have appeared in the media, where structures which appeared in good condition were failing.
Concerns about RAAC’s reliability were being raised as far back as the 90s. But the issue came to wider public attention this year when the government changed its stance on the material. They are now “less confident” that buildings with RAAC should remain open as they stand.
RAAC isn’t new: Our extensive experience
Jerry Nichols is Managing Director of Martech, our sister company and expert delivery partner for concrete testing and repair. Together, we’ve been carrying out RAAC inspections for years. We sat down to get his thoughts on how things have reached this stage:
“RAAC went into widespread use because it’s lightweight, has the right thermal properties, and because it was cheap. It found its way into institutional buildings, mostly single-storey; hospitals, schools, and military sites.
These structures were never meant to last, but maintenance records and instructions get lost over time. In some cases, people started treating buildings with RAAC the same as any others.
The issue is, in normal concrete, you can see the signs of deterioration over time, the cracks. Here, because RAAC is honeycombed you don’t see if water is penetrating, it soaks it like a sponge. The steel rebar can corrode as things expand and contract, but you don’t get any visible signs on the surface.”
What to do if your building contains RAAC
The possibility of hidden structural defects risking roof collapse might seem like cause for alarm. But the media furore around RAAC isn’t the full story. Yes, it’s a problem, but it’s one we have been tackling for a long time.
There are clear, reliable processes for detecting and removing the material. Jerry has this advice for building owners:
“Don’t panic. RAAC has only been found in a small fraction of properties that get checked for it. There are steps you can take yourself; think about the building’s age, was it built between 1930 and 1995? If so, then which parts of the building might have used it?
Walk around your property, eliminate things like timber roofs or other areas which wouldn’t contain RAAC. Then, if there are areas, you’re unsure about, talk to a building surveyor.”
Bellrock is proudly supporting the UK real estate sector as it gets to grips with this latest challenge. If you think your building might be at risk, talk to us and we can help you get to get to the facts.