Asbestos Roof Coating
A practical refurbishment option where replacement or overcladding is not presently viable.
Most industrial asbestos cement roofs are now several decades old and many have reached or exceeded their original anticipated service life.
Where budget allows, replacement or overcladding will normally provide the most comprehensive long-term solution. It can remove or encapsulate the asbestos-containing material while also creating an opportunity to improve the thermal performance of the building.
However, replacement is not always economically viable or appropriate to the immediate requirements of the project.
Where the roof remains structurally serviceable and its condition is suitable, a protective coating may provide a practical way of extending its useful life.
Liquasil Lite is available directly to competent contractors for use on suitably prepared asbestos cement roofs. Liquasil Approved Installer status is not required.
Products Used to Coat an Asbestos Roof
SWT Primer
For metal fixings and components
Applied to prepared hook bolts, fixings and other corroded metal components to provide corrosion protection and reduce the risk of rust staining through the completed coating.
Non-Sag Sealer
For fixings and localised defects
Applied over prepared and primed fixings to encapsulate them and reinforce failed seals. It may also be used for small, localised cracks and holes where the surrounding roof sheet remains serviceable.
Liquasil Lite
For the asbestos cement roof sheets
A silicone roof coating applied to the suitably cleaned and prepared asbestos cement surface to provide a protective finish and help slow further surface deterioration.
Is Coating The Right Option?
Many industrial asbestos cement roofs are now several decades old. Where budget and building use allow, replacement or overcladding should normally be considered before coating.
Replacement removes the asbestos cement sheets entirely, while an insulated overcladding system can encapsulate the existing roof and improve the thermal performance of the building. Both options generally provide a more comprehensive refurbishment than applying a coating to an ageing roof covering.
However, replacement or overcladding may not be economically viable or appropriate for every project. Where the existing sheets remain fundamentally serviceable, coating can provide a practical way of protecting the surface and extending the roof’s useful life.
Suitability depends upon condition rather than age alone. Localised cracks, small holes and deteriorated fixing seals may be capable of repair. Widespread cracking, severe surface deterioration, weakened sheets or extensive movement may indicate that the roof is unsuitable for coating.
Rooflights, gutters, fixings and other components must also be assessed. Older rooflights will normally be better replaced than coated. Corroded metalwork may require treatment with SWT Primer, while Non-Sag Sealer can be used around prepared fixings and for suitable localised defects. Defective gutters may require repair, replacement or lining with Gutterseal.
Cleaning and preparation must be carried out by a competent contractor using appropriate access, fall-protection and asbestos-control procedures. The condition of the sheets may only become fully apparent once preparation begins.
A roof coating protects the existing surface. It does not strengthen damaged sheets, correct structural movement or compensate for a failing roof structure.
Coating may be appropriate where:
- The sheets remain structurally serviceable.
- Deterioration is predominantly superficial.
- Damage is localised and repairable.
- Safe access and compliant cleaning can be provided.
- The objective is to extend service life rather than improve insulation.
- Replacement or overcladding is not presently economical.
Replacement or overcladding should be considered where:
- Sheets are extensively cracked, delaminated or structurally weakened.
- Fixings or supporting components are seriously deteriorated.
- There is widespread water ingress.
- Rooflights and other components are at the end of their service life.
- Improved thermal performance is required.
- The cost of safe access and preparation makes coating uneconomical.
Important Safety Information
Asbestos cement roofs are fragile.
Cleaning, preparation and coating must be undertaken by contractors with the appropriate competence, training, risk assessments and access arrangements.
Product availability does not imply that the work is suitable for untrained persons.
Can I Buy an Asbestos Roof Coating Directly?
Yes. Liquasil Lite, SWT Primer and Non-Sag Sealer can be purchased directly from Liquasil for use by competent contractors.
Liquasil Approved Installer status is not required to purchase or apply these products.
Asbestos cement roofs are fragile and work must be properly planned and carried out using appropriate access, fall-protection and asbestos-control procedures. The contractor remains responsible for assessing the project and carrying out the work safely and in accordance with current legislation and product instructions.
For larger projects, Liquasil can review photographs and approximate roof measurements to help identify the products and quantities likely to be required.
The contractor remains responsible for assessing the roof’s condition and suitability for coating.
Contractors who are unfamiliar with the products can attend practical training at Liquasil’s premises before starting work.
Training covers product preparation and application only and does not replace the asbestos, access or safety competence required for the project.
What Happened to Asbestoseal?
Asbestoseal was Liquasil’s original dedicated asbestos cement roof coating system and was the first system of its type to obtain BBA certification.
Liquasil decided not to renew the BBA certificate in July 2024 and Asbestoseal has now been discontinued.
Where coating remains an appropriate option, Liquasil Lite provides a more accessible alternative. It can be purchased directly for contractor-led projects and used with SWT Primer and Non-Sag Sealer where metal fixings, small cracks or localised defects require treatment.
Planning an Asbestos Roof Coating Project?
Liquasil Lite, SWT Primer and Non-Sag Sealer are available directly from Liquasil. Send us photographs and the approximate roof area and we can help identify the products and quantities likely to be required.