RAAC – What Landlords Need To Know
RAAC or reinforced autoclaved aerated concrete is in the news a lot at the moment, mostly in connection with its use in schools. However, it could also possibly have been used in some homes. Here’s what landlords need to know about RAAC, and dealing with any possible problems going forward.
What RAAC is
Concrete has been used in construction for centuries. Rome’s Pantheon dome was built with concrete almost 2,000 years ago and is still standing. Concrete became especially popular worldwide as a building material in the mid 20th century due to its cost-effectiveness compared to materials like brick and stone.
In simple terms traditional concrete uses cement and coarse aggregate. RAAC, however, is a unique lightweight concrete. It used cement, fine aggregates and an aeration agent which creates fine bubbles in the mixture. This mixture was poured into moulds containing steel reinforcement and then subjected to pressure and heat, something known as autoclaving.
It is said that reinforced autoclaved aerated concrete comprises up to 80% air. It is said to resemble an Aero chocolate bar.
RAAC was not used in every part of a building. RAAC was commonly used to produce precast concrete panels or planks which were used to build ceilings, floors, roofs, walls and building cladding. It can also be used to make blocks.
RAAC was mainly used in the UK between the early 1950s and the early 1990s. It is still used in some countries.
What’s the problem with RAAC?
RAAC is being portrayed as all bad right now, but there are some good reasons why it was used in the past.
RAAC was a very cost effective construction material which enabled new modern buildings to be built quickly, easily and cheaply. It could be made in a factory rather than on site. It was a form of prefabricated construction.
RAAC is light, both to work with and when used in construction.
RAAC has good thermal insulation, sound insulation and fire-resistant properties.
However, a key issue with RAAC is that it is not as strong as conventional concrete. It cannot carry as much weight nor tolerate as much movement.
RAAC is not water resistant and can also soak up moisture. This moisture can also corrode the steel reinforcement. Poor maintenance can contribute to its premature failure. (This can be a particular problem when RAAC is found in, for a example, a flat roof which suffers from leaks.)
RAAC has been found to fail suddenly without warning.
RAAC was produced by many different manufacturers, to different standards of manufacture and quality control, which are largely unknown.
It has been known for some time that RAAC has a limited lifespan. In many ways this is not much different to any building material, all of which have a limited lifespan. The problem with RAAC however is that it is only thought to have a lifespan of 30 years or so – very short compared to most.
In September 2022, the Office of Government Property sent a Safety Briefing Notice to all property leaders in local government stating ‘RAAC is now life-expired and liable to collapse’.
Has RAAC been used in houses and flats?
The fact that RAAC has been used in a number of schools is currently being widely reported in the media. This is not a new issue, however. The Building Research Establishment (BRE) identified that RAAC was problematic during the 1990s.
Although it is not clear as yet, it is quite likely that RAAC will have been used in other kinds of commercial and public buildings, such hospitals, theatres, sports centres, shops and offices.
Presently, it is also not clear as to whether or not RAAC has been used to any great extent in domestic houses and flats.
Broadly, it seems more likely that RAAC may have been used in flats more than in houses, and in council/social built properties rather than privately built ones. Much council/social housing stock built in the 1950s-1970s used low cost construction methods and RAAC could have been used for this reason. Some of this ex-council/social housing stock could now be in the private sector and owned by private landlords.
There are contradictory opinions from experts:
This report says that some building experts believe it is likely that RAAC was used in homes built between the 1950s and 1990s, in particular council housing.
This report says that a spokesperson for the Regulator of Social Housing (RSH) has said the watchdog does not believe RAAC to have been widely used in social housing in England.
A sensible conclusion, therefore, would be that RAAC may well be found in some housing but no one knows as yet.
How to identify RAAC
The only way to confirm that RAAC has been used in a building is to take advice from a suitably qualified surveyor or structural engineer.
Property owners shouldn’t attempt to identify RAAC themselves, but there are a few clues which might indicate if it could be present:
The property was built or extended between the early 1950s and mid 1990s and is of concrete construction. (It may also be present in other types of buildings however.)
The property has a flat roof and/or concrete wall cladding. (Although RAAC can also be used in pitched roofs.)
Any visible concrete panels fit the description of typical RAAC panels: They are often 600mm wide with chamfered edges and a smooth finish. They are white or light grey in appearance. (Although they may have had a protective coating applied.)
Any broken or detached pieces of concrete have a ‘bubbly’ or ‘Aero bar’ appearance.
The Department for Education has produced an identification guide which, although intended for schools, may be of some use: Reinforced Autoclaved Aerated Concrete (RAAC): Identification guidance
Is RAAC dangerous?
Potentially a building containing RAAC could be dangerous. The most serious risk is that a building could collapse. A slightly less serious risk is that pieces of RAAC could become detached and fall on occupants.
There have been no cases of total collapse to date. In 2017 and 2018 two different schools built with RAAC experienced a partial collapse of a roof. There were no injuries in either case.
There are no known cases of collapse or injury in domestic properties which have been attributed to RAAC.
What should I do if my rental property has RAAC, or I think it could have?
Landlords might make some basic checks as per the checklist above and then take expert advice.
What if my tenant is worried, or complains?
Given the amount of publicity that RAAC is being given by the media, and is likely to be given in future, it is possible that some tenants will be worried. They may decide to raise their concerns with the landlord or letting agent, or possibly raise a concern with the local council.
This will put landlords in a difficult situation. Although it is probably more likely that it does not there is a possibility that the property could contain RAAC.
In these cases landlords might make some basic checks as per the checklist above and then take expert advice.
Could I be breaking the law if my property contains RAAC?
Several pieces of legislation place a responsibility for safety with landlords.
Section 11 of the Landlord and Tenant Act 1985 covering repairs and maintenance sets down landlords’ obligations regarding ‘the structure and exterior of the property’ – plus certain amenities within the property. The Housing Act 2004 makes landlords responsible to local authorities for keeping their properties safe and free from hazards.
In a leasehold property the freeholder may handle maintenance but responsibility may rest with the landlord.
Landlords should not hesitate to take expert advice where necessary.
RAAC and local authority housing enforcement
Many landlords will ask, how will local housing authorities approach the RAAC issue. Will local authorities intervene, or take enforcement action?
The situation is likely to be different depending on whether a property is part of a council or social housing development or not.
The Regulator of Social Housing (RSH) has written to all registered social housing providers in England recommending they ascertain if their properties contain RAAC.
Some housing associations have already commenced checks to identify the presence of RAAC.
It is unlikely local housing authorities will check privately owned property for RAAC unless a query or complaint is made to them, although they have the power to do so.
The Housing Act 2004, covering England and Wales, empowers local authorities to inspect property in their area for faults (or deficiencies as they are known) and ensure it provides a safe and healthy environment for the occupants and any visitors. An inspection will involve using the Housing Health & Safety Rating System or HHSRS to assess a building including its structure as well as other aspects.
The inspection will look for deficiencies which create hazards within 29 different areas and also consider the usage and occupation of the property. A scoring system is used to compile the results and hazards are rated as category 1 (more serious) or category 2 (less serious) hazards.
The RAAC issue might be covered under section 29 of the HHSRS hazard profiles. Section 29 is titled ‘Structural Collapse and Falling Elements’. This states: ‘This category covers the threat of whole dwelling collapse, or of an element or a part of the fabric being displaced or falling because of inadequate fixing, disrepair, or as a result of adverse weather conditions. Structural failure may occur internally or externally within the curtilage threatening occupants, or externally outside the curtilage putting at risk members of the public.’
Local authorities can take enforcement action as a result of an inspection. This can include improvement notices, prohibition orders, hazard awareness notices, demolition orders and slum clearance declarations.
More information can be found in:
Housing Enforcement Action Under Part 1 of the Housing Act 2004 – A Closer Look
It should be said that at this stage it is largely unknown how local authorities will react if RAAC is found in domestic properties.
What will happen with buildings that incorporate RAAC?
Will buildings containing RAAC need to be repaired, or even demolished?
Rectification will almost certainly be needed. There may also need to be mitigation measures in the meantime.
It has already been reported that some schools containing RAAC may need to be demolished, as the cost of repairs is likely to be greater than the cost of rebuilding.
Will insurance cover any RAAC issues?
This is very much an unknown question at the moment. Buildings insurance can cover structural failure and/or any related damage but this depends on the cause. It does not usually cover wear and tear, nor repairs needed due to defective building materials or work.
Summary
In summary, it needs to be borne in mind that the issue of reinforced autoclaved aerated concrete in domestic buildings is very much an ongoing story. No one really knows as yet to what extent, or even if, RAAC has been used in houses and flats nor how safe or unsafe it might be.
Landlords will need to be proactive and monitor how things develop in order to reduce the risk to their tenants, and also to themselves.
photo sourced from the Department of Education: Reinforced Autoclaved Aerated Concrete (RAAC): Identification guidance August 2023
