Asbestos cement roofing and cladding is still present on hundreds of thousands of commercial buildings across the UK. Warehouses, factories, agricultural buildings, and industrial units built between the 1950s and 1990s commonly feature asbestos cement sheets that are now weathered, porous, and releasing fibres.
Removal is expensive, disruptive, and generates hazardous waste. For the majority of buildings where the asbestos cement is structurally sound, encapsulation is the recognised alternative — sealing the material in place with a specialist coating system that stops fibre release, waterproofs the roof, and extends the building’s working life by decades.
This guide explains how asbestos encapsulation works in practice, what coatings are used, when it is the right choice, and what UK regulations require of building owners.
What Is Asbestos Encapsulation?
Asbestos encapsulation is the process of applying a specialist coating to asbestos-containing materials (ACMs) to seal them in situ. The coating bonds to the surface, locks down loose fibres, and creates a continuous waterproof membrane that prevents further deterioration.
For asbestos cement roofs and cladding, encapsulation typically involves cleaning the surface, priming where necessary, and applying a polyurethane or elastomeric coating in multiple passes. The result is a sealed, weatherproof surface that can be maintained and recoated in future without disturbing the asbestos beneath.
Encapsulation is not a bodge or a temporary fix. It is a recognised treatment method referenced in the Health and Safety Executive’s (HSE) guidance and widely used across UK commercial property. When carried out correctly with appropriate products, an encapsulated asbestos roof can perform for 20 years or more before maintenance is required.
Asbestos Encapsulation vs Removal: When to Choose Each
The decision between encapsulation and removal depends on the condition of the asbestos material, the building’s future use, and budget. Here is how they compare:
| Factor | Encapsulation | Removal |
|---|---|---|
| Cost | £25–£55 per m² (supply & fit) | £80–£200+ per m² (removal + new roof) |
| Disruption | Minimal — building stays operational | Major — scaffolding, containment, closure likely |
| Timescale | Days to weeks depending on area | Weeks to months, plus new roof installation |
| Waste | None — asbestos stays sealed in place | Tonnes of hazardous waste requiring licensed disposal |
| Regulatory | Non-licensed work (if no drilling/cutting) | Licensed contractor required (HSE licence) |
| Fibre risk during work | Very low — no breaking or cutting | Higher — removal generates airborne fibres |
| Building lifespan extension | 20+ years with maintenance | New roof lifespan (varies by system) |
| Tax relief | May qualify for Land Remediation Relief (150%) | May qualify for Land Remediation Relief (150%) |
Choose encapsulation when the asbestos cement sheets are structurally intact, the building will remain in use, and the priority is cost-effective long-term protection. Choose removal when the material is severely damaged, crumbling, or the building is being demolished or fundamentally altered.
How Asbestos Roof Encapsulation Works
A professional asbestos encapsulation project follows a clear process.
1. Survey and condition assessment
A qualified surveyor inspects the roof to assess the condition of the asbestos cement sheets. They check for cracks, broken sheets, moss and lichen growth, fastener corrosion, and overall structural integrity.
2. Surface preparation
The roof surface is cleaned using low-pressure washing to remove dirt, moss, and loose material. High-pressure washing is not permitted on asbestos cement as it can release fibres. Any bolt holes, cracks, or gaps are sealed before coating begins.
3. Primer application
A penetrating primer is applied to consolidate the surface and ensure proper adhesion of the topcoat.
4. Asbestos encapsulation coating application
The encapsulation coating is applied in two or more coats by airless spray, roller, or brush. Each coat must cure before the next is applied. The finished system forms a seamless, flexible membrane.
5. Inspection and sign-off
The completed encapsulation is inspected to confirm full coverage, correct film thickness, and proper curing. Documentation is provided for the building’s asbestos management plan.
Asbestos Encapsulation Coatings: GacoFlex U91 and U92
GacoFlex U91 (grey) and GacoFlex U92 (white) are polyurethane asbestos encapsulation coatings manufactured by Amrize and distributed exclusively in the UK by Duratite Building Products.
- Fibre lock-down — penetrates and bonds to weathered asbestos cement, permanently sealing loose fibres
- Seamless membrane — cures to form a continuous elastomeric coating with no joints or mechanical fixings
- UV and weather resistance — designed for full exposure to UK weather
- Colour options — U91 (grey) blends with existing cement profiles; U92 (white) provides a reflective cool-roof finish
- Overcoatable — can be recoated in future to extend protection
Which Buildings Benefit from Asbestos Roof Treatment?
- Warehouses and distribution centres
- Agricultural buildings
- Industrial units and factories
- Retail and trade parks
- Schools and public buildings
- MOD and military buildings
UK Regulations: The Duty to Manage Asbestos
Under the Control of Asbestos Regulations 2012 (CAR 2012), anyone with responsibility for maintenance of a non-domestic building has a legal duty to manage asbestos.
- Identify asbestos-containing materials in the building
- Assess their condition and the risk of fibre release
- Create and maintain an asbestos management plan
- Take action to prevent deterioration
- Review the plan regularly
Encapsulation is one of the recognised management actions under CAR 2012. Where it involves no drilling, cutting, or breaking of asbestos material, it is classified as non-licensed work under HSE guidelines.
Land Remediation Relief: Tax Advantages
UK companies that incur costs treating asbestos in commercial property may be eligible for Land Remediation Relief under Corporation Tax — a 150% tax deduction on qualifying expenditure.
Frequently Asked Questions
Is asbestos encapsulation a permanent solution?
Asbestos encapsulation provides long-term protection, typically 20 years or more before maintenance recoating is needed. The system can be recoated in future to extend its lifespan indefinitely without disturbing the asbestos material.
How much does asbestos encapsulation cost in the UK?
Asbestos encapsulation typically costs between £25 and £55 per square metre for supply-and-fit. This compares to £80–£200+ per square metre for full removal and replacement.
Do you need a licence to encapsulate asbestos?
Asbestos encapsulation by coating — where there is no drilling, cutting, or breaking of asbestos material — is classified as non-licensed work under the Control of Asbestos Regulations 2012. Workers must have Category A asbestos awareness training.
Can you paint over asbestos cement sheets?
Standard paint is not suitable for asbestos encapsulation. A purpose-formulated asbestos encapsulation coating such as GacoFlex U91 or U92 is required.
What is the difference between GacoFlex U91 and U92?
GacoFlex U91 is grey, blending with existing asbestos cement profiles. GacoFlex U92 is white, providing a reflective cool-roof finish that reduces solar heat gain and can improve a building’s EPC rating. Both offer the same encapsulation performance.
Does asbestos encapsulation affect building insurance?
Most insurers view professional encapsulation positively because it reduces fibre release risk. Inform your insurer that asbestos is present and has been encapsulated, and provide documentation for the work carried out.
Book a Free Asbestos Encapsulation Survey
Duratite provides free, no-obligation surveys for commercial buildings across the UK. We supply and install GacoFlex U91 and U92 asbestos encapsulation coatings through our nationwide network of approved installers.
Call us on 01208 832602 or request a callback to arrange your free survey.
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