Asbestos Flashband
Self-adhesive bituminous flashing strips reinforced with asbestos, used for weatherproofing roof junctions.
Description
Asbestos flashband is a self-adhesive flashing strip composed of a bituminous compound reinforced with an asbestos fibre mat or woven asbestos fabric, backed with a metallic foil facing — typically aluminium. It was manufactured from the 1940s through to around 1990 and marketed as a quick, easy-to-apply weatherproofing solution for flashing around chimneys, roof-to-wall abutments, pipe penetrations, skylight surrounds, and other roof junctions where a watertight seal was needed.
The asbestos content in flashband products varies from 5 to 15 per cent, with chrysotile being the most common fibre type. The asbestos reinforcement provided tensile strength, crack resistance, and durability to the bitumen matrix, allowing the strip to bridge gaps and withstand thermal movement without tearing. The aluminium foil surface reflected heat and provided UV protection.
Asbestos flashband was enormously popular with both professional roofers and DIY homeowners because of its simplicity of application — peel, stick, and press. It required no specialist tools, hot bitumen, or lead-working skills. This accessibility meant it was used on a vast number of buildings as both an original installation and as a repair material. It is found on residential houses, garages, sheds, commercial buildings, and even temporary structures.
In its applied state, asbestos flashband is generally non-friable because the asbestos fibres are encapsulated within the bitumen. The aluminium foil facing provides additional containment. The risk of fibre release is low while the flashband remains adhered and undisturbed. However, when the material ages, the bitumen can dry out and the foil may degrade, exposing the fibre-reinforced core. Peeling off old flashband during roof repairs can tear the asbestos mat and release fibres. Heating the material to soften the adhesive is also hazardous.
When roof repairs require the removal of old flashband-type flashing, the material should be tested for asbestos before disturbance. If confirmed, careful removal by peeling (rather than scraping or heating) with appropriate wetting is necessary. All removed material must be treated as asbestos waste. Modern self-adhesive flashing strips are manufactured without asbestos and provide equivalent or superior performance.
Countries where commonly found
Commercial brands
How to identify
Asbestos flashband typically has a shiny aluminium foil surface and is found as a strip of material 50 to 300 mm wide, adhered to roof junctions, chimney bases, pipe collars, and wall abutments. When peeled back or cut, you may see a grey or white fibrous mat layer within the bitumen. The material becomes more brittle and cracked with age, and the foil may be partially delaminated. Any flashband installed before 1990 should be tested if removal is planned.
Health risk & friability
This material has a risk level of 2 out of 5.
It is classified as non-friable, meaning the asbestos fibers are tightly bound within the material matrix. When in good condition and left undisturbed, the risk of fiber release is low. However, cutting, drilling, sanding or breaking the material can release dangerous fibers.
What to do if you find this material
Do not scrape, heat, or forcefully pull off old flashband without first testing for asbestos. If the flashband is intact, well-adhered, and not being disturbed, it can be left in place. When roof repairs require its removal, have a sample tested first. If asbestos is confirmed, peel the material carefully while keeping it damp, collect all debris, and dispose of it as asbestos waste. Modern asbestos-free flashband or lead flashing are suitable replacements.
Frequently asked questions
Does all old flashband contain asbestos?
Is flashband on my chimney dangerous?
Can I stick new flashband over old asbestos flashband?
Related materials
Other asbestos-containing materials you might encounter.
Asbestos Roofing Felt
Bituminous roofing felt reinforced with an asbestos fibre mat, used on flat and low-pitch roofs.
Asbestos Bitumen Waterproofing
Bituminous waterproofing membranes and coatings reinforced with asbestos fibres for durability and flexibility.
Asbestos Sealant
Fire-stop and expansion joint sealants formulated with asbestos fibres for heat resistance and durability.
Asbestos Ridge Tile
Moulded asbestos cement ridge capping tiles used to seal the apex of pitched roofs.
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