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Types of Asbestos Cavity Wall Insulation

Homes built between 1900 and the 1980s often included asbestos insulation as it provided strong fireproof protection, making it a popular choice. Unfortunately, if disturbed it could release toxic asbestos fibers into the air.

When suspecting loose-fill or blown-in asbestos in your home, look out for pebble-like material in grayish brown, silvery gold or grayish green hues – these could contain zonolite, vermiculite or asbestos fibers.

What is Asbestos?

Asbestos is a group of naturally occurring minerals found as bundles of microscopic fibers found throughout nature. Asbestos fibres are known to be very strong, resistant to heat, corrosion and electricity and was widely used for construction due to its durability, fireproof properties and insulating capabilities. Unfortunately when asbestos becomes airborne through inhalation it can pose serious health hazards including lung cancer, mesothelioma and asbestosis (scarring of the lungs).

Before it was banned in the UK, asbestos was widely used in building materials and household equipment. It could often be found in attics or wall cavities for thermal and sound insulation; additionally it was also employed to insulate pipes and boilers. Asbestos comes in various forms that may be difficult to identify; we will go over some telltale signs below such as its blue-grey to white fluffy texture which breaks apart easily when tapped, along with paper or cardboard labels on its material.

Asbestos Insulation Boards

Asbestos Insulating Boards (AIB), commonly referred to in Scotland as AIBs, were commonly used as partition walls, ceiling tiles, soffits and other areas requiring fire resistance and insulation in homes throughout Scotland. Though asbestos fibres do not pose a health risk when left undisturbed, remodelling work and reconstruction projects can release airborne asbestos fibres, making this material hazardous if disturbed – hence it is always wise to conduct water absorption tests on insulation boards that could contain asbestos fibres for further investigation before use in homes with suspected insulation boards in Scotland.

Identifying this material can be challenging due to its similar appearance with modern fibre cement sheeting, but it’s easier by looking at the back where there’s a dimpled pattern known as “golf ball texture.” To remove responsibly, standard control measures like good fibre suppression/wetting, H type vacuuming and minimising breakage bring potential exposure well below 3 fibres per cubic centimetre of air.

Asbestos Loose Fill

Loose fill insulation was widely used prior to 1990 in homes constructed before this century. Consisting of loose material that could be blown into wall cavities, loose fill insulation may contain either vermiculite or cellulose containing asbestos fibres if disturbed, potentially releasing them into the atmosphere for inhalation.

Workers exposed to loose-fill insulation such as builders or those working in construction were vulnerable to asbestos exposure and developed health conditions such as mesothelioma. If you suspect loose asbestos in your home, please reach out to a professional surveyor immediately for testing and removal services.

Vermiculite is the most widely-used loose asbestos insulation product. This pebble-like substance comes in shades of greyish-brown or silvery-gold and typically features a pebbled appearance. Another popular form of loose asbestos insulation is rock wool. This material is manufactured by heating basaltic rock with added binders to near melting temperature before spinning it into fibers using air pressure.

Asbestos Pipe Insulation

Asbestos pipe insulation typically takes the form of loose corrugated paper that covers heating pipes in older buildings. It may also appear as plaster or cementous paste on certain types of pipes or where their bends occur, including corners.

All workers on pipes located within buildings constructed prior to 1980 must periodically assess asbestos pipe wrap for possible health hazards. Construction workers or shipbuilders who poured loose-fill asbestos into loose-fill asbestos molds, cut or handled old wrapping, sawed blocks of asbestos, or applied it sprayed or brushed had the potential to release enough dust to put people at risk of inhaling dangerous fibers.

When inspecting suspected asbestos pipe insulation, always wet the material first to be tested. When asbestos fibers become wetted they become easier to sample and this also slows the spread of possible contamination. When covering or sealing an asbestos insulation is present, repair options often include either covering or sealing it off as soon as possible.