Asbestos cement roofs,
assessed honestly
Most asbestos cement roofs do not need to come off. They need to be understood. Tens of thousands of UK commercial, industrial and agricultural buildings were roofed in asbestos cement sheeting between the 1950s and the late 1990s, and most are now weathered, leaking, or simply old. That does not automatically mean removal, and it rarely means panic.
Nova surveys the roof first, tells you what you are actually dealing with, and sets out the real options with the costs and the design life behind each one. We are a roofing contractor, not a removal company looking to sell you the most expensive answer. Where a roof is sound, we will say so.
Is an asbestos cement roof dangerous?
In good condition and left undisturbed, an asbestos cement roof presents a low risk. The fibres are locked into a cement matrix, not loose in the air. Risk rises when the material is weathered, broken, or worked on badly.
Asbestos cement is a bonded material. The asbestos fibres are bound into hardened cement, which is why it sits at the low end of the risk scale compared with friable materials like pipe lagging or insulating board. The danger is not the sheet sitting on the roof; it is fibre release when that sheet is cut, smashed, power-washed, or dropped. A weathered roof shedding fibres into the gutters and the yard below is a different proposition from a sound one, which is exactly what a survey establishes.
Sound and intact
Low risk. Often best managed in place with a record and periodic checks, rather than removed.
Weathered and shedding
Surface breakdown releases fibres into rainwater run-off, gutters and the ground below. Needs action, not necessarily removal.
Broken or disturbed
Storm damage, foot traffic through a fragile sheet, or careless work raises exposure sharply and changes how the job must be handled.
Do I have to remove an asbestos cement roof?
No. Removal is one of four options, and usually the most disruptive and expensive. The right answer depends on the condition of the roof, not on a default assumption that asbestos must always come off.
There is no legal duty to remove asbestos cement simply because it is there. The duty is to manage it: know where it is, know its condition, and control the risk. For many roofs the sensible route is to manage, protect, or cover, and to plan removal only when the sheets are genuinely beyond use.
Manage in place
Sound roof, recorded and re-inspected. Often the lowest cost and entirely legitimate where condition allows.
Encapsulate
A coating locks the fibres in place and re-weatherproofs the sheets. Extends life at a fraction of removal cost.
Overclad
A new metal or membrane roof installed over the existing sheets, which stay sealed beneath. No removal, building stays in use.
Replace
Full removal and a new roof, where the sheets are degraded or the building is being refurbished. The most disruptive route.
Where full removal is the right answer, we plan and coordinate it with licensed asbestos contractors and deliver the replacement roof, so you deal with one team and one accountable point of contact rather than stitching it together yourself.
Is working on an asbestos cement roof licensed work?
Usually not. Because asbestos cement is a bonded material, most work on it falls under non-licensed work in the Control of Asbestos Regulations 2012, even though the sheets contain asbestos. What changes the category is how badly the material is broken up, not which type of fibre it contains.
This is where a lot of advice goes wrong. People assume the fibre type decides everything. It does not. The classification rests on how friable the material is and how firmly the asbestos is bonded, not on the colour of the fibre inside it.
It matters in practice. Some profiles, such as the Trafford Tile, contained amosite, the brown asbestos, added for strength, alongside the more common chrysotile, the white. Brown asbestos sounds more alarming, and it is more hazardous as a loose fibre, but in a bonded cement sheet it does not change the regulatory position. Asbestos cement stays non-licensed because the substrate is bonded, whatever the fibre cocktail inside it. Cross-contamination during manufacture was common too, so a single sheet can carry more than one type. The bonded matrix is what governs the work, not the mix.
Where it does change. The category shifts when sheets are substantially broken up. Dropping an asbestos cement roof, or sheets shattered by fire or flood, creates dust and pushes the work into notifiable non-licensed work, and in some cases licensed work. To stay non-licensed, exposure must remain sporadic and of low intensity, below 0.6 fibres per cubic centimetre over ten minutes. The difference between a manageable job and a notifiable one is the survey and the method, not luck.
Manage, encapsulate, overclad, or replace?
The honest comparison, so the decision rests on evidence rather than a sales pitch. Every figure here is indicative; your roof gets its own numbers after survey.
| Option | What it is | When it fits | Building stays in use | Relative cost | Indicative design life |
|---|---|---|---|---|---|
| Manage in place | Record the roof, monitor condition, control the risk where it stands. | Sheets sound and not shedding. | Yes | Lowest | Existing life, monitored |
| Encapsulate | A coating seals the fibres in and re-weatherproofs the surface. | Weathered but structurally sound sheets. | Yes | Low to medium | Around 10 to 20 years by system |
| Overclad | A new roof installed over the existing sheets, which stay sealed beneath. | Sound structure, you want a long-life roof without removal. | Yes | Medium to high | New roof, typically 25 to 40 years |
| Full replacement | Remove the asbestos cement and install a new roof. | Sheets degraded, or building being refurbished or demolished. | Limited, usually out for a period | Highest | New roof, typically 25 to 40 years |
What survey do I need first?
Before any work, you need a valid asbestos survey and a site-specific method. The type depends on what you are planning.
Management survey
Locates the asbestos cement and assesses its condition so you can manage it and keep your asbestos register current. The baseline for any building.
Refurbishment and demolition survey
More intrusive, and required before major works, overcladding that fixes through the sheets, or removal. It finds what a management survey is not designed to.
Surveyed to HSG264
The HSE survey guide sets the standard. A survey that meets it gives you a defensible basis for the decision and the method statement that follows.
Inspected by drone
A weathered asbestos cement roof is fragile and hazardous to walk. A drone reads condition, fibre run-off, cracked sheets and gutter contamination without anyone setting foot on it, and gives you annotated evidence for your board and your register.
What does it cost, and how long does it take?
As a rule, managing in place costs least, encapsulation next, overcladding more, and full removal and replacement the most, often several times the cost of encapsulation. Timescales follow the same order.
We will not put a number on your roof before we have seen it, because an honest figure depends on area, condition, access, fixings and what sits beneath. What we will do is survey first, set out the route that genuinely suits the roof and your budget, and put the numbers, and the assumptions behind them, in writing. No padded scopes, no surprises on the final account, no removal sold where management would have done.
Can removing asbestos cement be offset against tax?
Often, yes. If removal is the right answer, the cost is not always as steep as it first looks. UK companies paying corporation tax can claim Land Remediation Relief on removing or containing asbestos in a building they acquired from a third party, which can take a real bite out of the bill.
Land Remediation Relief gives a qualifying company a deduction of 150 % of the money spent dealing with the asbestos, so for every £1 spent, £1.50 can be set against taxable profit. A company that is making a loss can surrender the relief for a cash credit worth 16 percent of the qualifying loss instead.
The conditions matter. You need to be a company within the charge to corporation tax, the building must have been acquired from someone else, and you must not have caused or added to the contamination yourself. The relief is not given automatically; it has to be claimed, and earlier periods can usually still be picked up within the normal time limits, so it is worth raising even on work already done.
Nova is not a tax adviser and this is not tax advice. The claim sits with your accountant. What we provide is the survey, the scope and the costed works documentation they need to substantiate it, so the relief is straightforward to evidence.
Common questions about asbestos cement roofs
Do I have to tell anyone I have an asbestos cement roof?
There is no duty to report the mere presence of asbestos cement, but under the Control of Asbestos Regulations 2012 the dutyholder for non-domestic premises must manage it: identify it, record its condition, assess the risk and keep an asbestos register. Any work that disturbs it must follow the regulations.
Can I overclad an asbestos cement roof without removing it?
Usually yes. Overcladding installs a new insulated metal envelope over sound asbestos cement sheets that stay in place underneath. Provided the sheets are not broken or fragmenting it is non-licensed work, and it avoids the cost and disruption of a full strip, though the asbestos remains in the building as a deferred liability.
Does the type of asbestos in the sheets change what I can do?
No. Asbestos cement can contain chrysotile, amosite or a mix, but the HSE classification is set by the bonded, intact substrate, not the fibre type, so it is non-licensed work in all cases. The fibre type does not change the method; the condition of the sheets does.
How much does it cost to overclad an asbestos cement roof?
It depends on the roof area, access, the existing structure and the specification, so there is no flat rate. We price per square metre after a survey establishes condition and access, and we set out the options with costs in writing before any commitment.
How long does overcladding last?
A well-specified overclad system typically gives a comparable service life to a new metal roof, often 25 years or more, backed by the manufacturer system warranty. Lifespan depends on the products chosen, the detailing and ongoing maintenance.
What happens to the asbestos cement when I sell the building?
It transfers with the building, along with the management duty and the future removal liability. A documented asbestos register and condition survey make a sale smoother and reduce the risk of price chipping, because the buyer can see exactly what they are taking on.
Can you survey an asbestos cement roof without closing the building?
Yes. A drone-led condition survey assesses the roof from above without anyone walking the fragile sheets and without disrupting the operation below. Where closer inspection is needed, access is planned to keep the building running.
Can I claim tax relief on removing asbestos cement?
UK companies subject to corporation tax can claim Land Remediation Relief at 150 percent of qualifying expenditure on removing or containing asbestos in a building acquired from a third party, provided they did not cause the contamination. Loss-making companies can take a 16 percent cash credit instead. The relief must be claimed and can be backdated up to around three years. Nova provides the works documentation an accountant needs to substantiate the claim.
Arrange a survey
Tell us the building and what prompted the call. We will confirm the survey fee and a date in writing.