RAAC Surveys for Clifton Diocese

RAAC Surveys for Clifton Diocese

We’ve recently been undertaking structural surveys of church buildings on behalf of the Diocese of Clifton, assessing the potential presence of Reinforced Autoclaved Aerated Concrete (RAAC), following national concerns about its long-term durability and structural performance.

RAAC is a lightweight, aerated precast concrete material commonly used in UK construction from the 1950s to the 1990s, particularly for roof panels. Made using fine aggregates and cured under pressure in an autoclave, it offered reduced weight but also lower strength and durability compared to traditional concrete.

To provide reinforcement, smooth steel bars were typically used and anchored with welded transverse bars. However, the limited bond between concrete and steel, combined with increased susceptibility to corrosion, has raised significant concerns over the structural integrity of RAAC panels.

We’re pleased to be supporting the Diocese in identifying and managing these risks through thorough inspection and clear engineering advice. 🏛️