If you have lifted an old floor tile and found a black adhesive underneath, discovered ageing roofing felt on a garage roof, or uncovered a black strip within an older wall, you may be looking at asbestos bitumen.
Asbestos bitumen is one of the most commonly overlooked asbestos-containing materials in UK buildings. Unlike pipe lagging or asbestos insulation board, it doesn’t look obviously hazardous. In fact, it often appears no different to ordinary roofing felt, black adhesive or waterproofing material.
Understanding what asbestos bitumen looks like, where it is commonly found, and when it may contain asbestos can help you avoid accidentally disturbing it during renovation, maintenance or demolition work.
What Is Asbestos Bitumen?
Asbestos bitumen is a black, tar-like material that was commonly used in older buildings for waterproofing, roofing and floor adhesives.
To make the material stronger, more durable and more fire-resistant, manufacturers added chrysotile asbestos fibres, also known as white asbestos. This is why older black bitumen products, particularly those installed before the early 1990s, can sometimes contain asbestos.
Although asbestos bitumen is usually lower risk than loose or friable asbestos materials, it can still release fibres if it is cut, scraped, sanded, burnt or removed incorrectly.
When Was Asbestos Bitumen Used?
Asbestos bitumen products were widely used in UK buildings throughout the mid to late twentieth century, particularly from the 1950s through to the 1980s.
Asbestos was added to bitumen to improve strength, durability and fire resistance, making it common in older floor adhesives, roofing felt, damp proof courses and waterproofing products.
Some asbestos-containing bitumen products may also have remained in use into the early 1990s, before asbestos was fully banned in the UK in 1999. If you find older black bitumen in a property built or refurbished during this period, it should be treated as potentially containing asbestos until tested.
What Does Asbestos Bitumen Look Like?
Asbestos bitumen usually looks like ordinary black bitumen, which is why it is so difficult to identify by sight alone. It does not look white, fluffy or obviously fibrous in the way many people expect asbestos to appear.
It is most often seen as a black or very dark grey material. Under old floor tiles, it may appear as a sticky, tar-like adhesive or, if aged, a brittle and powdery black residue. On roofs, it may look like standard black roofing felt or a dark waterproofing layer.
Common signs of asbestos in bitumen include
- Black or very dark grey colouring
- Thick, sticky or tar-like texture
- Roofing felt-style appearance in sheet materials
- Smooth, shiny or matte finish depending on age
- Cracked, brittle or powdery texture when degraded
- No visible asbestos fibres
These signs can help you recognise when bitumen may be present, but they cannot confirm whether it contains asbestos. The only reliable way to know is through professional sampling and laboratory testing.
What colour is asbestos bitumen?
Asbestos bitumen is usually black or very dark grey. It may look sticky, tar-like, smooth, brittle or powdery depending on age and condition. Colour alone cannot confirm whether asbestos is present, as modern asbestos-free bitumen can look almost identical.
Does All Black Bitumen Contain Asbestos?
No. Not all black bitumen contains asbestos.
However, many older black bitumen products used in UK buildings during the 1950s, 1960s, 1970s and 1980s were manufactured with asbestos to improve strength, durability and fire resistance. Some asbestos-containing bitumen products may also have remained in use into the early 1990s, before asbestos was fully banned in the UK in 1999.
The challenge is that asbestos-containing bitumen and modern asbestos-free bitumen often look virtually identical. Colour, texture and appearance alone cannot confirm whether asbestos is present.
If the material is in an older property, or you do not know when it was installed, it should be treated as potentially containing asbestos until professional testing confirms otherwise.
When was asbestos removed from bitumen products?
In many cases, asbestos bitumen can be left in place if it is in good condition and unlikely to be disturbed. This should only be decided after professional assessment, especially if renovation, roof work or flooring removal is planned.
What Products Commonly Contained Asbestos Bitumen?
Asbestos bitumen was used in a wide range of building products throughout the mid to late twentieth century. Some of the most common examples include:
- Black floor tile adhesive (often called black mastic)
- Roofing felt on garages, sheds and flat roofs
- Damp proof course (DPC) materials
- Bitumen waterproofing membranes
- Sink pads fixed beneath older kitchen sinks
- Bitumen coatings on steelwork and pipework
- Roof flashings and gutter linings
- Protective coatings applied to industrial equipment
Many of these products can still be found in buildings constructed or refurbished during the 1950s, 1960s, 1970s and 1980s. Because asbestos bitumen often looks identical to modern asbestos-free products, testing is usually required before any removal or refurbishment work takes place.
Is Asbestos Bitumen Dangerous?
Asbestos bitumen is generally considered a lower-risk asbestos-containing material because the fibres are tightly bound within the bitumen rather than being loose or friable.
When it is in good condition and left undisturbed, it’s unlikely to release significant amounts of asbestos fibres.
The risk increases when the material is disturbed through:
- Scraping or grinding floor adhesives
- Cutting or tearing roofing felt
- Drilling through damp proof course materials
- Breaking up aged or degraded bitumen
- Burning roofing felt or bitumen products
Burning roofing felt or other bitumen products is particularly hazardous, as it can release asbestos fibres into the air at much higher concentrations.
For this reason, older bitumen products should always be assessed before renovation, removal or demolition work begins.
What colour is asbestos bitumen?
Asbestos bitumen is usually black or very dark grey. It may look sticky, tar-like, smooth, brittle or powdery depending on age and condition. Colour alone cannot confirm whether asbestos is present, as modern asbestos-free bitumen can look almost identical.
What Should You Do If You Suspect Asbestos Bitumen?
If you suspect a bitumen product may contain asbestos, stop work immediately and avoid cutting, scraping, sanding, drilling or disturbing the material any further. Keep others away from the area until you know what you are dealing with.
The next step is to arrange professional sampling and testing. Once the results are confirmed, you can make an informed decision about whether the material can be left in place, safely managed or removed.
For homeowners planning renovation work, a residential asbestos survey can help identify hidden risks before work begins. For commercial properties, schools, industrial sites and public buildings, asbestos management responsibilities may also apply under the Control of Asbestos Regulations 2012.
Talk to Fibre Safe
If you suspect asbestos bitumen in your property, whether beneath floor tiles, within roofing felt, damp proof course materials or older coatings, Fibre Safe can help.
We provide asbestos surveys, sampling, testing and consultancy for domestic, commercial and public-sector properties across Liverpool, Wirral, Chester, North Wales and the wider North West.
To speak to a specialist today to arrange professional asbestos testing and get clear advice on the safest next steps.
Call 0800 458 4136
Or send a message here.
