What is RAAC? -Reinforced Autoclaved aerated concrete
-Reinforced form of lightweight concrete
-Concrete without aggregate
-Common in public buildings example schools and, hospitals from 1950's-1990's
-Less common in residential
-Found in limited buildings from 1990's -2000's
Why are there concerns?
- Not as durable
- No fixed timing/lifespan; typically discussed 30 years of lifespan however this cannot be defined as lifespan is dependent on several factors
- Lifespan depends on the maintenance
- Risks and concerns are related to sudden failure which again can happen due to various reasons
- Reasons for failure could be water ingress from leaking roofs which can cause corrosion to reinforcement, excessive thermal degradation or poor original installation
-Typically made of galvanized or stainless steel reinforcement and therefore could last well in case of not coming in contact with water
-Typical period of the buildings aligns with asbestos usage in buildings and therefore when carrying out surveys asbestos surveys to be undertaken
Identifying-
- Information gathering from the Council can help, as they may have records and information
-Checking construction record drawings
-Suitable surveys by qualified persons
-Use of Space can help decide the level of risk and corrective measures required
Regular Planned Preventive Maintenance (PPM) surveys should assist in identifying & managing potentially defective materials.