Asbestos Cement Roofs: Overclad, Encapsulate or Remove?

Large profiled asbestos cement sheeting is common on industrial units, warehouses and other commercial buildings put up before 2000. If your building has one, the roof is probably nearing the end of its useful life, and the question is not ‘repair or replace’ but ‘what do we do about the asbestos?’. There are four routes: manage it in place, encapsulate it, overclad it, or remove it.

This guide sets out what HSE says about each route, what the owner’s duties are, and the questions to put to a contractor. It is general information for commercial and industrial buildings in Great Britain, not a substitute for a competent asbestos surveyor or the HSE’s own task guidance.

What the material is

HSE describes asbestos cement roofing as large profiled asbestos cement sheeting, with related products including wall cladding, gutters and downpipes, and flues. It is cement mixed with asbestos, and HSE says the risk increases when the material is damaged: where asbestos cement is so badly damaged that there is significant risk of exposure to fibres, a risk assessment will show whether a licensed contractor is needed (HSE: locations of asbestos).

The same sheeting is also fragile. HSE’s roof work guidance says all roofs should be treated as fragile until a competent person has confirmed they are not, and its agriculture pages note that asbestos cement sheeting can shatter without warning (HSE: roof work, HSE: falls through fragile roofs). A leak survey, a fixing repair or a gutter clean all involve access onto it. The repair and planned maintenance guide covers the fragile-roof and CDM duties.

Your duty to manage

The Control of Asbestos Regulations 2012, regulation 4, places the duty to manage asbestos on the owners and occupiers of commercial premises who are responsible for maintenance and repair (HSE: the duty to manage asbestos in buildings). In practice that means finding out whether asbestos is present, recording it in a register, assessing the risk, having a plan, and passing the information to anyone who might disturb it (HSE: provide information to anyone who might disturb asbestos). An asbestos cement roof should be on that register whatever you decide to do with it.

The four routes

Route	What happens to the asbestos	What the sources say
Manage in place	Stays; condition monitored	The duty to manage applies. HSE lists cleaning weathered asbestos cement roofing as a lower-risk task
Encapsulate or seal	Stays, sealed	HSE gives encapsulation and sealing-in work on asbestos-containing materials in good condition as an example of non-licensed work
Overclad	Stays, covered by a new roof layer	The HSE pages checked do not mention overcladding. NFRC publishes industry guidance on removal and overcladding of asbestos cement roof sheets (HSGS44) and a client consideration guide (GN75)
Remove	Leaves the building as waste	Non-licensed if the sheets are carefully handled and removed without breaking up; notifiable non-licensed work if they will be substantially broken up

Sources: HSE non-licensed work with asbestos and notifiable non-licensed work; NFRC HSGS44 and GN75 listings.

Removal: licensed, non-licensed or notifiable

HSE’s examples for asbestos cement roof sheeting are specific:

• Non-licensed: maintenance work on sheeting, tiles and rainwater goods; removing sheeting carefully without breaking it up; working with weathered sheeting that is not otherwise substantially damaged.
• Notifiable non-licensed work (NNLW): removing sheeting that is substantially damaged or broken up, for example after fire or flood damage; or removal that will substantially break the sheeting up, creating significant quantities of dust and debris, such as ‘dropping’ an asbestos cement roof.

For NNLW, HSE says notification is made using the online form only (not by phone or post), before the work starts, with no minimum notice period and no need to wait for permission. The enforcing authority depends on the premises: HSE covers sites such as factories and construction sites, local authorities cover shops and offices. A risk assessment still decides whether the work needs a licensed contractor.

Overcladding: the questions to ask

Overcladding leaves the asbestos in place under a new roof layer. That can reduce disruption, and a new insulated layer can improve energy performance, but it changes your obligations rather than ending them. Ask any contractor proposing it:

• How will the asbestos remain recorded in the register and communicated to future maintenance contractors?
• How are the new fixings made? Drilling asbestos cement has its own HSE task guidance (the Asbestos Essentials sheet on drilling holes in asbestos cement), so fixings through the old sheets are a work method to be assessed, not a detail.
• Has the structure been checked for the added load? NFRC’s guidance says a comprehensive survey of the existing roof and its structure is part of planning.
• Does the new insulated layer count as renovation for the Building Regulations? The approved document lists ‘providing a new layer through cladding’ as renovation of a thermal element, so ask building control (see the building regulations guide).
• What is the end-of-life plan? The asbestos still has to be removed one day, probably by someone working above or around a new roof.

Also ask your insurer and, if the building is let or may be sold, your solicitor how an overclad roof with asbestos beneath it will be treated. The over-sheeting and over-cladding guide explains the construction side.

A survey comes before any of it

HSE separates two survey types. A management survey supports the asbestos register during normal occupation. A refurbishment or demolition survey is needed before major refurbishment or demolition; it is more intrusive, involves destructive inspection, and must find asbestos hidden in the building fabric before work starts. HSE says the surveyor must be competent, strongly recommends accredited providers (UKAS is the sole recognised accreditation body in Great Britain), and notes that only laboratory analysis confirms whether a material contains asbestos (HSE: arrange an asbestos survey).

A re-roof, overcladding or removal project is the kind of work that calls for the refurbishment survey. The wider condition survey (membrane, insulation, structure, drainage) is a separate exercise; the commercial roof survey guide shows how the two fit together.

Choosing a route

• Sheets in good condition and the building has a long life ahead: manage or encapsulate, on the register, with scheduled inspections.
• Roof is failing but the budget cannot cover removal: overcladding is the route owners most often weigh, with the questions above answered in writing first.
• Major refurbishment, change of use, or the building is being sold or redeveloped: removal is usually the clean answer; HSE describes the aim of the refurbishment survey as removing the asbestos that must come out before work starts.
• Sheets already broken or storm-damaged: treat as a risk-assessed emergency, and check whether the work is notifiable.

NFRC frames the choice between overcladding and removal as a question of health and safety, cost, regulation, operations and long-term asset value, which is a fair way to organise the discussion with your advisers. For industrial buildings in particular, the industrial roof refurbishment guide and the industrial flat roofing guide set out the replacement options once the asbestos question is settled.

What drives the cost

• The survey and laboratory analysis.
• Roof area, height and access, including edge protection and any need to protect fragile sheets and rooflights.
• Condition of the sheets, which decides the work method and whether notification is needed.
• For removal: handling, transport and disposal of asbestos waste, and the replacement roof.
• For overcladding: the new roof system, added structure, and the long-term register and end-of-life implications.

No reliable commercial-scale price range for any route was found in the sources checked, so none is given here. Get written quotes against one scope and read the commercial flat roof cost guide for how the replacement roof itself is priced.

Common questions

Is an asbestos cement roof dangerous if left alone?

HSE says the risk increases when asbestos cement is damaged. Intact, well-maintained sheeting is managed under the duty to manage, which means it is recorded, inspected and protected from disturbance.

Is it illegal to remove asbestos roof sheets, and do I need a licensed contractor?

Removal is not illegal in itself, but it is regulated. HSE treats careful removal of asbestos cement roof sheeting without breaking it up as non-licensed work, which still needs a risk assessment and trained workers. If the sheets will be substantially damaged or broken up, the work is notifiable non-licensed work and must be notified online before it starts. A risk assessment decides whether a licensed contractor is needed.

Can I overclad an asbestos cement roof instead of removing it?

It is done, and NFRC publishes guidance on it, but the asbestos stays and your duties continue. The HSE pages checked for this guide cover removal and encapsulation and do not mention overcladding, so put the questions in this guide to your contractor and surveyor in writing.

Do I need an asbestos survey before re-roofing?

HSE says a refurbishment or demolition survey is needed before major refurbishment, and it recommends accredited surveyors. Ask a competent asbestos surveyor to confirm what your project requires.

Sources and last checked

Last checked on 20 October 2026 against the sources below.

• HSE: locations of asbestos and taking the right action
• HSE: non-licensed work with asbestos and notifiable non-licensed work
• HSE: the duty to manage asbestos in buildings, provide information and arrange an asbestos survey
• HSE: roof work and falls through fragile roofs
• NFRC HSGS44 and GN75 client consideration guide (listings only; the documents themselves were not read for this guide)
• Control of Asbestos Regulations 2012