Asbestos in Roofing Felt – The Complete Guide

Written by Tom Yates . Edited

Fact Checked by William Wright, NEBOSH

Between the 1920s and 1990s, asbestos was used in a large array of construction products due to its durability and fire-resistant properties. A popular product was asbestos roofing felt and this was used as both a top layer roofing solution, and as an underlay to things like roof slates. In this guide, I explain how asbestos was used in roofing felt, how you can identify it, and the potential danger it poses. 

How was Asbestos Used in Roofing Felt?

Asbestos roofing felt was incredibly popular and it was most commonly used for outbuildings including garages and sheds. The roofing was typically made into rolls and cut to size to fit over the outbuilding roof, but it was also manufactured into smaller rectangular shingles.

Aside from outbuildings, it was less commonly used in DPC (damp proof courses) and as underlay to roofing slates. Therefore, it can also be found on property roofs and not just outbuildings.

Why Was Asbestos Used in Roofing Felt?

Asbestos was combined with other materials to benefit from its fire-resistance and durability. This made it ideal for use in roofing products as it help improved the durability against the unpredictable weather conditions in the UK.

Asbestos is also incredibly easy to work with and could be combined with other materials such as bitumen which made it an inexpensive alternative.

How to Identify Asbestos in Roofing Felt

Asbestos roofing felt typically has a black, grey, and white speckled textured appearance. It is one of the easier asbestos products to identify although it can look similar to standard roofing felt. Usually, standard roofing felt has a slight green tinge but it could easily be mistaken for asbestos roofing felt. The HSE guide on Roofing Felt[1] provides a few decent pictures. 

If you are struggling to distinguish the type of felt, the easiest solution is to either get an asbestos surveyor out or use an asbestos testing kit to take sample. These kits contain PPE (coveralls, breathing mask, gloves, etc.), sample bags, and instructions. You can then safely take a sample, bag it, label it, and send it off to the lab for analysis.

You get the results back within 24-72 hours with a certificate showing the contents of the sample and whether it contains asbestos. After this, you can then decide an appropriate course of action. 

Is Asbestos Roofing Felt Still Common in the UK?

Although asbestos was banned in the UK in 1999, there is still a surprising number of outbuildings and garages that have asbestos felt roofing. It is typically found in older garages and outbuildings that have been standing for years and are rarely used, or in derelict properties that are uninhabitable.

When assessing if your property contains asbestos roofing felt, if it was built after 1999, there should be no risk. However, if you have an older property built before this, consider any outbuildings you have and your property roof.

How old are they? Have any of them been replaced after 1999 or are they all original? If they are originals and installed before 1999, there is a chance they could contain asbestos.

How Dangerous is Roofing Felt with Asbestos?

Asbestos roofing felt is actually considered low-risk and the HSE classifies work with this product as non-licensable, i.e., you don’t need a licensed contractor to remove it. 

This is because it is not friable (can’t be crushed by hand pressure), and the asbestos content is typically 10% or lower (although there were varieties that contain 80%+ asbestos and these were usually uncoated and not combined with something like bitumen). 

Even though it is classed as low risk, we don’t advise attempting to remove asbestos roofing felt yourself. If the fibres of the felt are disturbed and broken, they can become airborne and inhaled. This can lead to permanent lung damage and in severe cases, lung cancer.

References 

[1] – HSE – Roofing Felt