Where appropriate, asbestos can be encapsulated, rather than being removed. A risk assessment should be carried out prior to any asbestos encapsulation works to ensure this is the best course of action.
Asbestos encapsulation can take many different forms, depending on the nature of the material. Encapsulation can be defined as the application of an impervious material, which is secured over or around an asbestos containing material (ACM), and is designed to prevent the release of fibres under foreseeable conditions, such as vibration, impact and age degradation. Encapsulation should maintain the beneficial properties of the original asbestos application and maintain it in a safe condition.
As encapsulation of an ACM is classified as working with asbestos, it is subject to the requirements of the Control of Asbestos Regulations 2012 (CAR). Encapsulation should always be carried out by a licensed contractor wherever possible, however there are some circumstances where this is not required.
Types of Asbestos Encapsulation
An example of mechanical encapsulation would be by using board or sheet materials and simply painting with domestic paint. Normally board or sheet materials should not be fixed through the asbestos material. However, if the assessment shows that the best method for mechanical protection requires screw fixing through the asbestos material, appropriate controls should be put in place to minimise fibre release and spread of contamination.
Elatomer coatings consists of a liquid encapsulant applied in layers suitable for encapsulation of sprayed coatings, insulation, boards and other fibrous forms of ACM. A product used for such forms of encapsulation is Idenden ET150.
Elastomeric coatings can provide impact resistance as well as elasticity, especially when incorporating a reinforcing membrane. Correctly applied to asbestos applications, these kinds of treatment may provide up to 20 years of life if undisturbed.
Penetrating encapsulants are suitable for encapsulation of sprayed coatings, insulation and boards. Products available for such treatments include Incorez and Serpiflex.
Spray applied encapsulants are available which will penetrate friable ACMs. Such encapsulants have many advantages over other forms, but their application must follow manufacturers’ instructions for effective results.