What is Asbestos?
Asbestos is a material that has long been used to enhance insulation in both residential and commercial buildings. Furthermore, long before (and after) people knew it contained various levels of asbestos, vermiculite, another material with exceptionally good fire-resistant qualities, was also used for insulation.
If your building was constructed (or renovated) before or during the 20th century, it’s highly likely that any insulation within the building could potentially contain asbestos. Asbestos was used in many forms such as asbestos attic insulation, asbestos wool insulation, loose fill insulation material, plus others, until 1999, when it was banned in the UK.
Nevertheless, asbestos is still used in many countries around the world because it has excellent insulating and fire-resistance properties and is inexpensive, durable, and readily available.
Asbestos is most commonly found in places such as :
- Pipe insulation and wraps
- Cavity wall insulation
- Wall or attic insulation
What Does Asbestos Insulation Look Like?
Asbestos-ladened insulation may not always be visible to the casual observer. It is commonly found around pipes, boilers, and heating systems, particularly in older buildings. Although it can have a variety of forms, this type of asbestos is easily recognised by its powdery, flaky look.
Asbestos is classified into six types:
- Crocidolite
- Chrysotile
- Tremolite
- Actinolite
- Anthophyllite
- Amosite
When examined using a microscope, each kind of asbestos has a distinct appearance; yet they do appear to look extremely similar to the naked eye.
It could be difficult to recognise when asbestos pipe insulation has been used since it is frequently painted over or has a protective coating. Asbestos that is found on pipework is one of the most hazardous materials that contain asbestos. If pipe lagging is disturbed, asbestos fibres are easily dislodged.
Asbestos can also be confused with cellulose insulation, so it is important you know the differences when identifying asbestos insulation.

What Colour is Asbestos Insulation?
The three most frequent forms of asbestos used in the UK building sector were crocidolite, amosite and chrysotile.
- Crocidolite – these fibres are thin, brittle, needle-like, and usually blue or grey coloured.
- Amosite – brown asbestos, like crocidolite, is typically made up of needle-like fibres.
- Chrysotile – sometimes known as white asbestos, has curved and flexible fibres.
Tremolite, actinolite, and anthophyllite were far rarer and were not commercially available. However, they could be identified as contaminants in other varieties of asbestos and other materials obtained from the mining process.
- Tremolite – this mineral can occur in white, green, grey, and various other light colours.
- Actinolite – these fibres are typically dark in colour.
- Anthophyllite – has a drab green, grey, or brown colour.
The smooth fibres that make up asbestos are often combined with other materials, so detecting the presence of asbestos with the naked eye is pretty much impossible.
Asbestos Insulation Dangers
When asbestos fibres are released into the air, they significantly threaten health. Once in the air, they can easily be inhaled through the nose and mouth, becoming lodged inside the body.
Some of the dangers of asbestos exposure include asbestos related diseases such as:
- Mesothelioma is a type of cancer that originates in the thin layer of tissue that covers some of your organs.
- Asbestosis is a dangerous long-term lung ailment characterised by shortness of breath.
- Lung cancer
It’s worth mentioning that these health issues may not manifest themselves until later in life, possibly 35 years or more after the initial exposure.

Different Types of Asbestos Insulation
Thermal insulation containing asbestos-containing materials (ACMs) is classified into four types:
Asbestos Block Insulation
The procedure of glueing a slab of an insulating block to a wall is called block insulation. Although this is a relatively easy method of insulating buildings, the concern is that in the past, these blocks included a significant amount of asbestos (in some cases, practically pure asbestos), which presents a severe exposure risk if the blocks are disturbed or damaged in any way.
You can find asbestos block insulation in the following places: walls, floors, and ceilings.
Loose-Fill Asbestos Insulation
One of the most harmful types of insulation is loose-fill insulation. It is exceedingly fibrous and quickly releases fibres into the air when poured or blown into roof voids and hollow spaces. When you think about it, It is pretty shocking when you actually realise what percentage of asbestos is found in thermal insulation; this substance, in particular, is typically made up of 100% asbestos.
Loose-fill asbestos insulation could be found in areas of buildings that aren’t generally readily accessible such as wall cavities and attic floors.
Spray-On Asbestos Insulation
Spray-on insulation was commonly used to prevent fires from spreading to steelwork and other structures. The material was blended with binding chemicals and sprayed onto the surface of whichever material required fire protection, as the name implies.
This technique was incredibly harmful, causing millions of asbestos fibres to disperse in the immediate atmosphere. In addition, the sprayed coatings contained a significant amount of asbestos, which is easily broken and prone to damage after application.
Spray-on asbestos insulation might be found in irregularly designed buildings that would be difficult to insulate with more conventional insulation, as well as walls, ceilings, and structural steelwork.
Pre-formed and Loose (applied) Asbestos Insulation.
Asbestos is often found in old insulating coverings used on plumbing, heating, and ventilation equipment. This insulation can gradually deteriorate and potentially release substantial amounts of asbestos fibres into the air.
Where you could find asbestos insulation: plumbing/HVAC plants such as ducts and pipes.
How to Remove Asbestos Insulation
Only the Health and Safety Executive licensed contractors can remove asbestos insulation materials. These contractors employ highly qualified and competent workers who understand the dangers of asbestos removal.
In addition, they have specialised apparatus and decontamination facilities (decon units) to ensure that the work is carried out safely and that any materials containing asbestos are disposed of in the proper manner.
Incorrect asbestos removal can significantly increase exposure levels for both the operatives as well as other people in the immediate area.
To complete the removal of any asbestos, a specialised asbestos removal company must be appointed. Their operatives will either remove the asbestos completely, or encapsulate (cover) it, so there is no risk to human life.