Asbestos insulation board (AIB)

What the board actually is

AIB is a low density calcium silicate board with asbestos fibre mixed through it, usually amosite, sometimes with chrysotile and occasionally crocidolite in the older or more specialised products. The asbestos content typically runs somewhere between fifteen and forty per cent by weight, against roughly ten to fifteen per cent in asbestos cement. That difference is the whole story. Cement locks its fibre into a hard matrix. AIB is soft enough to snap over your knee, and it gives fibre up willingly.

In the UK it was sold under names such as Asbestolux, Turnasbestos and Marinite, and it went into buildings in volume from the late 1940s until manufacture here effectively stopped around 1980. Amosite and crocidolite imports were banned in 1985. Anything I find in a building of that era gets presumed AIB until analysis says otherwise, and I do not soften that presumption because the panels look modern. I have pulled Asbestolux out from behind 1990s plasterboard overboarding more times than I can count.

Where I keep finding it

The same places, decade after decade:

• ceiling tiles and the firebreaks sitting above suspended ceilings, which nobody looks at until a sparky lifts a tile;
• service risers, boxed-in ducts and partition linings in offices and schools;
• soffits and infill panels below windows, especially on system-built and CLASP-type schools;
• panels behind warm air heating units and boilers, and the linings inside airing cupboards;
• bath panels, fire door cores and the panel above a flat entrance door;
• stairwell, corridor, garage and plant room linings where fire resistance was the point.

Position tells me where to look hard. It never tells me what the board is. A 1972 airing cupboard lining and a 1998 replacement can sit an inch apart and look identical under two coats of emulsion. For broader identification pointers, see what does asbestos look like.

Why I will not call it by eye

AIB turns up grey, off white, beige, painted, skimmed, papered and tiled over. A cut edge can look fibrous, but so does perfectly innocent wood fibre board. The old trick of checking for a slightly dimpled or lightly textured face and a soft, chalky edge will get you the right answer often enough to be dangerous and wrong often enough to matter.

So do not drill a test hole, snap a corner off or lift a fitting to see the reverse. That single exploratory act is the exposure. Where a sample is needed, it should be taken under controlled conditions by someone competent to do it, and analysed by a laboratory holding UKAS accreditation to ISO/IEC 17025 for asbestos identification. Analysis is the only thing that settles it.

The ordinary jobs that turn into asbestos jobs

Nearly every AIB exposure I have investigated started as something trivial. Downlighters cut into a 1970s ceiling. Data cable dropped through a riser. A bath panel taken out on a Friday afternoon. A fire door drilled for a closer. None of those people set out to work on asbestos, and all of them created a release.

Removing AIB, or any work likely to break it up or deteriorate it significantly, generally requires a contractor licensed by the Health and Safety Executive under the Control of Asbestos Regulations 2012. There is a narrow non-licensed route for short duration work, but it only applies where every condition in the regulations is met, and in practice it is a much smaller doorway than the contractors quoting for it tend to suggest. That call gets made by a competent person before anyone starts, on the basis of the material’s condition, the task, its duration and the likely exposure.

Asbestos awareness training does not qualify anyone to touch AIB. It qualifies them to stop.

What a survey has to tell you

For management purposes I expect the material identified or clearly presumed, located, quantified, and given a material assessment score under the HSG264 algorithm, so the register and management plan are working from something real rather than a hunch.

Before refurbishment or demolition, a refurbishment and demolition survey is required for the areas affected. HSG264 keeps it separate from a management survey for good reason: hidden firebreaks, riser linings and boards behind finishes have to be found, so far as is reasonably practicable, before intrusive work starts. A report saying asbestos may be present is worthless to the man with the reciprocating saw. He needs to know which panels are live and what controls apply to them.

Where the duty sits

Regulation 4 of CAR 2012, the duty to manage, applies to non-domestic premises and to the common parts of domestic blocks. If you hold that duty you must find asbestos that could be disturbed in normal use or foreseeable maintenance, record it, and pass the information to anyone liable to disturb it.

A private householder does not carry that duty inside their own home. The moment they engage a trade, though, that employer or contractor carries duties of their own to assess the risk and prevent exposure, and they cannot do it on your say-so about a board you have never had tested. Get the assessment done before you appoint the trades, not after.

If a panel does get damaged

Stop. Everyone out, door shut, nobody sweeping or hoovering, nobody putting tape over it to be helpful. Tell whoever is responsible for the building, follow the steps on the suspected asbestos page, and get competent advice before anyone goes back in or picks the job up again. Sampling and laboratory analysis are covered on the asbestos testing page.