Asbestos Cement Products: Corrugated Sheets, Downpipes and Flue Pipes — Low-Risk Handling and Disposal

Summary

Asbestos cement was the most widely used ACM in UK construction between the 1930s and the mid-1980s. It was mixed as a slurry — roughly 10–15% chrysotile (white) asbestos fibre bound in Portland cement — and pressed into sheets, pipes, and moulded sections. The cement matrix binds the fibres tightly, which is why asbestos cement is classified as a "lower risk" material compared to sprayed coatings or pipe lagging. However, "lower risk" does not mean zero risk, and the fibres are still carcinogenic if released.

Products made from asbestos cement are found on millions of UK buildings: corrugated roof sheets on garages, outbuildings, agricultural buildings, and industrial units; flat sheet cladding on soffits, fascias, and wall panels; downpipes and gutters; flue pipes and chimney sections; cold water cisterns; and rainwater goods. The most important indicator of condition is whether the surface is intact. Weathered, cracked, or friable (crumbling) AC presents a significantly higher fibre-release risk than smooth, sealed surfaces.

Tradespeople encounter AC most commonly when re-roofing outbuildings, replacing guttering, removing chimneys, or during general renovation of pre-1990 buildings. The primary legal obligation is to identify suspected ACMs before starting work, stop if you find unexpected material, and follow the correct handling and disposal procedures. Ignorance of the presence of asbestos cement is not a defence under health and safety law.

Key Facts

• Fibre content — typically 10–15% chrysotile (white) asbestos by weight; some older products contain amosite (brown) or crocidolite (blue) [verify]
• Classification — non-licensed ACM under the Control of Asbestos Regulations 2012; some notifiable non-licensed work (NNLW) categories may apply
• Risk level — low when intact; significantly higher when broken, cut, drilled, or weathered to a friable state
• Colour clues — AC is typically grey or dark grey; colour alone does not confirm or rule out asbestos content
• Age threshold — assume any cement sheet, downpipe, or flue pipe installed before 2000 may contain asbestos; use 1999 as the practical cut-off since asbestos was banned in new products in the UK in 1999
• Testing — only accredited laboratory analysis (UKAS-accredited) can confirm or rule out asbestos content; visual inspection alone is not sufficient
• Corrugated sheet dimensions — typically 1,000–1,200mm wide, 2,400–3,600mm long, 6mm thick; bolted through the crown of the corrugation
• Downpipe diameters — common sizes 68mm, 100mm; lengths typically 1,800mm; socket-and-spigot joints
• Flue pipe — asbestos cement flue sections were widely used on gas, oil, and solid fuel appliances; typically 100–200mm diameter
• Cisterns — rectangular AC cold water storage tanks were standard in loft spaces until the 1970s–80s; internal surfaces may be scaled or deteriorated
• Disposal classification — asbestos waste is hazardous waste under the Hazardous Waste (England and Wales) Regulations 2005 (as amended); must be consigned to a licensed hazardous waste facility
• Double-bagging — waste AC must be double-wrapped in 1,000-gauge polythene sheeting, sealed, and labelled with UN 2590 (asbestos, chrysotile) or relevant UN number
• Waste carriers — must hold an Environment Agency waste carrier licence; check the public register before hiring
• Hierarchy of control — encapsulation (sealing or overlaying) preferred over removal where the material is in good condition and not creating a risk

Quick Reference Table

Detailed Guidance

Identifying Asbestos Cement Before Starting Work

The starting point for any job involving pre-2000 outbuildings, industrial units, or domestic extensions is a visual inspection for potential ACMs. Asbestos cement corrugated sheets have a distinctive grey appearance, lighter than concrete, and a smooth pressed surface. The bolts are typically lead-headed or steel, passing through the crown of the corrugation. Flat AC soffit boards are often painted and may not be obvious without touching — they have a slightly hollow sound when tapped compared to timber.

If you are unsure, do not start work until samples have been tested by a UKAS-accredited laboratory. Sampling itself is a disturbance task and should follow Control of Asbestos Regulations 2012 guidance: use a damp cloth to suppress dust, take the minimum sample needed, seal immediately, and send to the laboratory.

An asbestos management survey (the type conducted in occupied buildings) may not cover areas like garage roofs or outbuildings. For refurbishment or demolition work, a more intrusive refurbishment and demolition survey is required. See refurbishment demolition survey process.

Handling AC Roofing Sheets

Where removal is necessary and the material has been confirmed as asbestos cement, the following controls apply for non-licensed work:

Before starting:

• Inform the employer or principal contractor; record the work in a risk assessment
• Ensure all workers hold, at minimum, Cat A asbestos awareness training
• Notify HSE if the work qualifies as notifiable non-licensed work (NNLW): for AC roofing, this is generally work lasting more than one hour cumulative per week [verify specific thresholds]
• Prepare the work area: seal off below the roof if there is any risk of debris falling into an occupied area
• Have suitable PPE ready: minimum FFP3 disposable respirator, disposable coverall (Type 5/6), gloves

During work:

• Keep sheets damp throughout removal using a garden sprayer or low-pressure hose — this suppresses fibre release
• Remove fixings carefully; avoid breaking sheets wherever possible
• Do not use angle grinders, disc cutters, or high-pressure washers on AC — these generate high fibre concentrations
• Work from a stable platform; do not walk on AC sheets (they are brittle and may break)
• Place sheets carefully on the ground; do not drop or stack roughly

Waste handling:

• Wrap sheets in 1,000-gauge polythene immediately after removal; double-bag
• Label bags/wrapped sheets with the correct asbestos hazard label
• Complete a waste consignment note (hazardous waste consignment note in England)
• Transport to a licensed hazardous waste facility — not a general skip or household waste site

Encapsulation as an Alternative to Removal

Where AC roofing or cladding is in sound condition and there is no operational reason to remove it, encapsulation is the preferred option. Encapsulation involves applying a penetrating sealant or overcoating that binds any surface fibres and reduces fibre release from weathered surfaces.

Encapsulation products must be specifically designed for use on asbestos-containing materials — standard exterior masonry paint is not appropriate. The material must be cleaned of biological growth (moss, algae) before treatment, but this cleaning must be done carefully and without high-pressure washing.

The encapsulated surface should be managed in an asbestos register and re-inspected periodically (typically annually for accessible areas). Future contractors working on the building must be informed that an ACM has been encapsulated on site.

Downpipes, Gutters, and Flue Pipes

These smaller-diameter products are lower risk due to their smooth internal surface and sealed joints, but the same principles apply. When replacing AC downpipes or gutters:

• Do not cut or saw sections unless unavoidable
• If cutting is required, use a fine-toothed handsaw (not a power saw), keep the cut damp, and wear FFP3 protection
• Joints on AC pipes are typically socket-and-spigot type joined with a putty or mortar; splitting these joints may release some dust
• Flue pipes from old boiler installations may have internal deposits (combustion residues) combined with fibre; treat as higher risk

Frequently Asked Questions

Do I need a licensed contractor to remove asbestos cement roofing sheets?

No — asbestos cement is a non-licensed ACM. You do not need an HSE-licensed contractor. However, workers must hold asbestos awareness training (Cat A minimum) and the work must be done in accordance with the Control of Asbestos Regulations 2012. For larger jobs or where the sheets are significantly degraded, consider engaging a specialist even if not legally required.

Can I put asbestos cement sheets in a general skip?

No. Asbestos waste — including asbestos cement — is classified as hazardous waste and must be disposed of at a licensed hazardous waste facility. Putting it in a general skip is illegal and can result in prosecution. The waste carrier must also be registered.

What does notifiable non-licensed work (NNLW) mean for AC removal?

NNLW is a category of non-licensed asbestos work that must be notified to the relevant enforcing authority (usually the HSE or local authority) before starting. For sporadic low-intensity work on AC — such as replacing a few roof sheets — NNLW requirements may not apply. For more substantive work, notification, health surveillance, and record-keeping requirements apply. Check HSE guidance or consult an asbestos consultant if you are unsure which category your work falls into.

How do I dispose of an old asbestos cement cold water cistern?

Treat the cistern as asbestos waste. Drain it, allow to dry (or leave filled if drained safely), then wrap in 1,000-gauge polythene double-bagged with hazard labels. Do not break it up. Transport via a registered waste carrier to a licensed hazardous waste facility. You will need to complete a hazardous waste consignment note.

What PPE is required for non-licensed AC work?

As a minimum: FFP3 disposable respirator (not an FFP2 or surgical mask), Type 5/6 disposable coverall, nitrile gloves. For extended work or large roof removals, a half-face respirator with a P3 filter is more practical. Remove and bag the coverall before leaving the work area. Do not brush down the coverall — roll it off from inside out.

Regulations & Standards

• Control of Asbestos Regulations 2012 (SI 2012/632) — principal UK regulations; Regulation 4 (duty to manage), Regulation 7 (identification), Regulation 11 (licensing), Regulation 17 (training)

• Hazardous Waste (England and Wales) Regulations 2005 (as amended) — governs classification and disposal of asbestos waste

• Environmental Protection Act 1990 — duty of care provisions covering waste transport and disposal

• HSE MDHS100 — methods for the determination of hazardous substances; guidance on sampling techniques for ACMs [verify currency]

• HSE L143 (Managing and Working with Asbestos) — Approved Code of Practice and Guidance for the Control of Asbestos Regulations 2012

• BS EN 481 — workplace atmospheres; size fraction definitions for measurement of airborne particles (historical reference) [verify]

• HSE — Asbestos: The basics — overview of asbestos types and risks

• HSE — Non-licensed work with asbestos — guidance on NNLW categories and controls

• HSE — Asbestos essentials task sheets — practical task-by-task guidance for non-licensed work

• Environment Agency — Hazardous waste: dispose of it correctly — waste carrier registration and consignment notes

• UKAS — Find an accredited laboratory — for locating accredited asbestos testing laboratories

• asbestos awareness training — Cat A and Cat B training requirements

• refurbishment demolition survey process — when a full survey is required before work starts

• asbestos floor tiles — another common low-risk ACM found in refurbishments

• asbestos in pipe lagging — higher-risk ACM often found alongside AC in industrial buildings