Reinforced Autoclaved Aerated Concrete (RAAC)

This subject has generated a lot of recent publicity and as a result has raised queries within the music industry, particularly in relation to schools, theatres, venues and studios.

What is RAAC?

RAAC is a highly aerated, lightweight, concrete based material, with different material properties to conventional concrete. It was typically used in precast panels in walls, roofs, and sometimes floors. Problems associated with older forms of the construction include high deflection, corrosion and spalling, and, where there is a low-end bearing, the possibility of sudden collapse due to cracking.

It should be noted that traditional concrete is a highly reliable material with high compressive strength. When combined with steel reinforcement to become ‘reinforced concrete’ it can form some of the world’s biggest and heaviest loaded structures such as high-rise buildings, bridges, and dams.

The Institute of Structural Engineers has advised that “If properly designed, manufactured, in good condition with good bearing, RAAC installations are considered safe. However, the panels can creep and deflect over time, and this can be exacerbated by water penetration. A more recent incident indicated that if they have insufficient bearing and their structural integrity is compromised, they can fracture and collapse with little or no warning.”

RAAC use grew in the 1950s onwards and is particularly evident in larger buildings including those in health, university, local authority, schools and meeting halls. Concern has grown about the deterioration of its structural integrity, often related to water penetration. This deterioration has led to structural failures. It is of particular concern in load bearing areas. This risk appears to grow 20/30 years after initial use.

Like many of these problems it has been known for some time but only recently has there been a growing pressure for clear policies to be adopted. Hospitals have been addressing the problems for some years and now the emphasis has been on schools.

Risk Assessments

Anywhere RAAC has been used needs to be properly risk assessed which we think should follow the approach for asbestos. RAAC risk assessments should:

• locate where RAAC exists in a building
• confirm where it does not
• clarify where there is doubt until a full investigation is complete

If you have any concerns that RAAC exists in a building in which you are working or have been booked to work in the near future, you should ask your engager if a suitable Risk Assessment has been completed and ask to see it.

If you meet with any objection to such a request or you aren’t satisfied with the results, please contact your Regional Office who will be happy to pick the issue up on your behalf.

Work Cancellation

There may be instances where your work has been cancelled due to the closure of a building through the presence of RAAC in its structure. If this is the case, whether you still receive payment or not will be down to the terms of the contract under which you were engaged.

If you need assistance assessing whether you have been paid appropriately or your engager disagrees with your reading of the contractual terms, please contact your Regional Office who will be happy to assist you.

Read our specific advice for musicians who teach affected by RAAC closures.