Asbestos Insulating Board — universally known as AIB — is widely considered the most hazardous asbestos-containing material found in UK buildings. Unlike asbestos cement, which is a bonded material that holds fibres securely, AIB has a much higher asbestos content and a semi-friable nature that makes it far more likely to release fibres when cut, drilled, broken or disturbed.
What Is Asbestos Insulating Board?
AIB is a calcium silicate board product manufactured with asbestos fibres — typically amosite (brown asbestos) or a combination of amosite and chrysotile (white asbestos) — making up 15–40% of the material by weight. Trade names include Asbestolux, Marinite, Limpet, Turnaboard and Cape Insulation Board. It was manufactured in the UK from the late 1940s through to 1980, when the importation of amosite and crocidolite was banned. Chrysotile-based AIB continued until the complete UK ban in 1999.
Where Was AIB Most Widely Used?
- Suspended ceiling tiles in offices, schools, hospitals and public buildings
- Partition walls and corridor linings in commercial and institutional buildings
- Fire door linings and intumescent panels
- Lift shaft walls and service duct linings
- Soffit boards and fascia panels on pre-1980 buildings
- Boiler houses and plant room wall and ceiling linings
- Behind electrical switchgear panels and distribution boards
Buildings constructed between 1950 and 1980 — schools, hospitals, local authority housing blocks, offices and public buildings — are the most likely to contain AIB in significant quantities.
Why Is AIB Classified the Most Hazardous?
Three factors combine: a high fibre content (15–40% vs 10–15% in asbestos cement); a semi-friable nature that allows fibres to be released by drilling, sawing, sanding or even scraping; and a predominance of amosite, the fibre type associated with the highest rates of mesothelioma. Disturbed AIB in poor condition is a medical emergency — the area must be evacuated and secured immediately.
Licensed Removal Is Non-Negotiable
AIB is a licensable asbestos material under CAR 2012. It cannot be legally removed by an unlicensed contractor, a builder, a property owner or a handyman — regardless of the area involved. Our licensed AIB removal service involves purpose-built enclosures, negative pressure units, controlled wet removal and mandatory four-stage clearance testing. For full details, see our AIB removal service page. For a real-world case study, see our Moddershall AIB removal project. If a survey is needed first, our trusted surveying partners can arrange this — see our surveys page.