Make Safe Your Roof: Expert RAAC Refurbishment Solutions
In September 2022, the Office of Government Property sent a Safety Briefing Notice to all Property Leaders, confirming the dangers of RAAC, stating that ‘RAAC is now life-expired and liable to collapse’. At Tremco we have partnered with UK-wide Structural Engineers and specialist Contractors to deliver a holistic approach to RAAC roof refurbishment.
How we can help.
- We offer a complimentary roof survey to assess the condition and build-up of your roof, including the deck.
- Partnered with national Structural Engineers to support with a final expert analysis of RAAC.
- We can carry out further investigation via our roof diagnostics. This is where we can use thermal technologies to confirm whether moisture is present. If moisture is present this can require more urgent action. The moisture in the roof could increase the likelihood and speed of deterioration of the RAAC roof deck.
- If remediation is required, we handle every aspect of roof refurbishment, starting from the initial assessment and survey, all the way through design, supply and installation.
- The new roof will include thermal efficiency upgrades and comply with Broof(t4) classification for enhanced fire safety.
- Our team of Tremco Trusted Partners is equipped with extensive expertise and training to ensure safe and professional removal and replacement work.
- Additionally, we offer a Single-Point Warranty of up to 25 years, providing further assurance to our valued clients.
To take the first step towards securing a reliable and durable roof, book your initial consultation and inspection with us today.
Whether you are concerned about RAAC in your building or working on a RAAC project and looking for roof remediation support...
Book your FREE initial survey today!
(and yes, our surveys are really free - and there is no obligation)
What is RAAC?
Reinforced Autoclaved Aerated Concrete (RAAC) is a ‘bubbly’ lightweight form of reinforced concrete that is manufactured with extremely fine aggregates meaning its structurally and physically different from traditional higher-density concretes.
Although categorised as concrete, RAAC has a cellular-type construction that is formed by a chemical reaction during the curing process when foaming gases are emitted creating a honeycomb-like structure. The resulting precast planks are then heat and pressure-treated (Autoclaved) to provide additional strength. This manufacturing process was cost-effective and created an incredibly lightweight building material that can be thermally efficient and fire resistant but has significantly lower structural capacity than most structural grade concretes making it susceptible to fracture or complete failure over time.
Where it’s found?
Often found in public sector buildings, especially schools and colleges between the 1950s and 1990s.
RAAC was specified in multiple building applications such as flat or pitched roof structural decking, supporting floor and wall constructions, and eaves designs.
What are the risks?
In September 2022, the Office of Government Property sent a ‘Safety Briefing Notice’ to all Property Leaders, confirming the dangers of RAAC, stating that ‘RAAC is now life-expired and liable to collapse’.
< View recent ITV News coverage of issues experienced in a UK school.
How to identify it?
RAAC can be easily identified by its distinct characteristics and properties. When cut or broken, RAAC reveals a porous structure with a honeycomb-like appearance. Its surface is often rough or textured, and it may display visible holes or pores. Additionally, RAAC is commonly used in precast planks that feature chamfered edges, making identification straightforward.
Traditionally, it was believed that visual deterioration would precede RAAC failures. However, recent experiences have shown that roofs can fail without any warning signs.
According to Professor Goodier, tens of thousands of these structural panels can be found in a wide range of buildings, particularly those constructed in the 1960s and 70s. Many of these panels are exhibiting signs of wear, tear, and deterioration. The majority of them form flat roofs, making access, surveying, maintenance, and replacement challenging.
