Reinforced Autoclaved Aerated Concrete
An update on the presence of Reinforced Autoclaved Aerated Concrete (RAAC) in our properties.
In late December 2023, Almond HA discovered that RAAC roof panels had been used in the construction of 318 properties in the Craigshill area of Livingston. Of these, the panels in 209 houses and 96 flats (with 34 being directly affected) were encapsulated under pitched roofs which reduces the risk presented by wind and water penetration. The properties were built in the 1960’s by Livingston Development Corporation and subsequently refurbished in the early 1990’s prior to stock transfer.
In total, 13 properties were identified which do not have pitched roofs. We had previously carried out surveys which identified the presence of RAAC in both walls and roofs in 7 of these properties and as such are commencing with the process of rehousing those tenants who are affected.
In mid-January tenants whose homes contains RAAC were visited by our Asset and Housing Officers to inform them of the presence of RAAC and confirm that detailed surveys would be undertaken by a Structural Engineer in the coming weeks.
On completion of the detailed survey work, we will be developing a programme to address the issue in line with Surveyor’s recommendations. Any works required will be delivered alongside planned investment due in the properties.
RAAC is a reinforced form of lightweight concrete. It has no aggregate unlike common concrete. RAAC was mainly used to form roof planks, wall panels, and sometimes floor planks in the UK from the mid-1950s to the mid-1990s.
The Institute of Structural Engineers issued updated guidance in terms of the investigation and assessment of existing RAAC panels in 2023. RAAC has proven to be not as durable as other concrete building materials. It is very different from traditional concrete and, because of the way in which it was made, much weaker. The useful life of such planks has been estimated to be around 30 years – but will last longer if the building is well maintained.
There is a risk it can fail, particularly if it has been damaged by water ingress, if it was not formed correctly when originally made, or from poor installation.
The concerns about RAAC are solely linked to its durability and structural performance. There is no evidence to suggest it poses any other health risk.
The structural condition will need to be determined by a suitably qualified engineer. Condition and risk assessments will inform a management plan, as well as helping to determine whether replacement needs to be considered and when.
If the analysis and risk assessment find that the planks can be retained, it will be important to monitor the situation carefully for signs of deterioration in future.
Remediation works will vary from building to building, and it is not possible to provide definitive guidance on how long remediation might take. Further surveys will determine the remediation required.
Removal of a RAAC flat roof for example will require tenants to vacate the property during the remedial works.
The Association does not have any responsibilities or maintenance or repair obligations in relation to privately owned properties. Property owners have sole responsibility their property. As such, we have no responsibility for identifying or repairing privately owned homes should RAAC be found to be present.
In cases where owned properties are located in blocks where RAAC has been identified in the common close and the Association has the role of Factor, we will liase with owners to ensure necessary monitoring and remedial works are carried out.
If you have received a letter from us advising we had identified RAAC in neighbouring properties or are concerned that your home may contain RAAC, we recommend that you have it inspected by a qualified Chartered Structural Engineer in accordance with the guidance issued by the Scottish Government and the Institution of Structural Engineers. The chartered Structural Engineer will be able to assess the condition of the concrete planks, whether RAAC is present, and advise you on any necessary mitigation works.
In the meantime, there are a few things that you can do to make your home safer:
- Check for any signs of damage to the RAAC planks, such as cracks, bulges, or discoloration.
- If you see any damage, contact a qualified chartered Surveyor/Structural Engineer immediately. You should not undertake remedial action yourself.
It is important to take independent advice on the potential risks to you and to have your home inspected by a qualified Structural Engineer if you are in any way concerned.
While the Association cannot provide you with property, legal or financial advice, you can find contact details for suitably qualified professionals via the RICS Website or via the Institution of Structural Engineers website.
West Lothian Council’s scheme of assistance aims to provide homeowners with information and guidance to help them effectively maintain and repair their own properties.
Surveys have been carried out in Ash, Beech, Chestnut, Elm, Fir, Hazel, Juniper, Linden, Maple, Oak, Poplar, Rowan and Spruce Groves.
Visual surveys have been carried out by Structural Engineers and where identified, any deflection in the roof panels measured. Disruptive surveys are now being planned in a small number of properties initially to ascertain location and extent of reinforcement within panels.
This has not yet been identified.
If there are to be remedial works required, we will carry out some pilot projects in advance of a larger programme of works to identify what if any disruption works may cause to neighbouring owner occupiers.
The Association has checked our stock and can confirm only the streets listed are affected. We have written to all customers confirming if their home is or isn’t affected.