Important safety note: Asbestos is hazardous when fibres are released into the air. If you suspect a material might contain asbestos, avoid disturbing it. Stop work, restrict access, and arrange proper identification/sampling via a competent person. In the UK, the HSE is clear: only carry out asbestos-related work if you are properly trained and have the right equipment, and you should stop immediately if you discover suspected asbestos during a job.
Quick answer: what is an “asbestos sealer”?
An “asbestos sealer” (often called an asbestos encapsulant) is a specialist coating or barrier system used to encapsulate an asbestos-containing material (ACM). Encapsulation means applying an impervious material over or around the ACM to help prevent fibre release under normal, foreseeable conditions such as minor knocks, vibration, or ageing.
In plain English: it’s about locking fibres in and reducing exposure risk—not removing the asbestos.
On this page
What asbestos sealers are (and what they are not)
Asbestos sealers are not “magic paint”. A proper asbestos sealer/encapsulant is designed for fibre-locking performance and durability in asbestos management. Standard household paint is not automatically suitable as an asbestos control measure.
They are also not a substitute for removal when removal is required. Encapsulation leaves the asbestos in place. That can be a sensible option in specific circumstances, but it must be chosen based on the material type, condition, location, and the likelihood of future disturbance.
Encapsulation is usually considered after a risk assessment has already concluded that leaving the ACM in place is the best risk-managed option. In UK guidance, encapsulation is discussed as a management method that should sit within an overall asbestos management plan.
Encapsulation vs Enclosure vs Removal: what’s the difference?
These terms get mixed up a lot. The key difference is whether asbestos is left in place and managed, physically boxed-in, or removed entirely.
| Option | What it means | When it can make sense | Main drawback |
|---|---|---|---|
| Encapsulation (sealers/encapsulants) | A specialist coating or treatment that helps lock fibres in by forming a barrier or stabilising the surface. | When the ACM is in a viable condition and can remain undisturbed as part of a management plan. | Asbestos remains in the building and must be recorded, monitored, and managed. |
| Enclosure (boxing-in/boarding) | A physical barrier that prevents contact and damage to the ACM (often used alongside other controls). | When the risk is mainly from impact/accidental contact and the ACM can be safely protected without disturbance. | Poor detailing or later alterations can still lead to disturbance; asbestos still requires ongoing management. |
| Removal | The ACM is taken out of the building and disposed of correctly under controlled conditions. | When the ACM is damaged, likely to be disturbed, or refurbishment plans make “leave in place” unrealistic. | More disruption and cost, and often requires specialist (sometimes licensed) contractors. |
Rule of thumb: If a material is likely to be disturbed (now or later), “manage in place” options become much harder to justify.
UK compliance and asbestos waste: the bit people often miss
Licensed work vs non-licensed work vs NNLW (high level)
In the UK, asbestos work is regulated. Broadly, work may fall into one of these buckets:
- Licensed work: higher-risk work that must be carried out by an HSE-licensed contractor.
- Non-licensed work: lower-risk tasks still requiring suitable controls and competence.
- NNLW (Notifiable Non-Licensed Work): a subset of non-licensed work with extra requirements such as notification, medical surveillance, and record-keeping.
Why this matters: “Encapsulation” can still be classed as work with asbestos, and the correct category depends on the type of asbestos material, its condition, and how likely the work is to create dust/fibre release.
Asbestos waste and disposal (don’t treat it like normal DIY waste)
Any asbestos-containing material that’s being thrown away is classed as asbestos waste — and that includes contaminated PPE, cleaning rags, and anything that can’t be properly decontaminated.
- Classification: asbestos waste is treated as hazardous waste in England and Wales (and special waste in Scotland) above the relevant thresholds.
- Packaging: waste should be securely wrapped/double-packaged and labelled appropriately (commonly using an inner asbestos-waste bag and a clear outer bag, where suitable) to prevent fibre escape.
- Don’t mix waste: asbestos waste must not be mixed with general waste “to dilute it”.
- Disposal route: disposal must be via an authorised route — for householders this is typically through your local council’s guidance (some sites accept small amounts of correctly wrapped cement-bonded asbestos; rules vary by area).
Homeowner reality check: even if you’re not an employer, you still need to prevent exposure and dispose of any asbestos waste legally. If you’re unsure about category, handling, or disposal, the safest option is to use competent professionals.
Types of asbestos sealers and encapsulation systems
“Asbestos sealer” is an umbrella term. In practice, products and systems fall into a few common categories:
| Type | How it works (conceptually) | Typical use cases | Key limitation |
|---|---|---|---|
| Penetrating encapsulants | Low-viscosity liquids that soak into certain ACMs and bind fibres internally. | Some porous or friable surfaces where penetration is beneficial. | Performance depends heavily on substrate condition and correct specification. |
| Bridging encapsulants / high-build coatings | Forms a durable surface membrane over the ACM (often applied in multiple coats). | Where a tough surface film is needed to resist minor knocks and wear. | Doesn’t “fix” unstable, delaminating, or heavily deteriorated ACM. |
| Reinforced elastomeric systems | A coating plus reinforcing layer to improve impact resistance and longevity. | Higher-risk areas where extra durability is required. | More complex specification; still requires ongoing management. |
| Water-based epoxy / resin systems | Creates a hard, cleanable, impact-resistant surface (sometimes with glass fibre reinforcement). | Industrial/commercial settings where cleanability matters. | Must be compatible with the ACM and environment; not a DIY decision. |
| Mechanical encapsulation (boarding, cladding, enclosures) | Physically boxes-in or protects ACM without relying solely on a coating. | Preventing impact damage to panels/pipe runs in accessible areas. | Fixing methods and detailing must avoid disturbing the ACM. |
| “Lockdown” sealers (post-removal) | Applied to surfaces after asbestos removal to seal residual fibres in the work area. | Part of professional abatement workflows. | Not an “encapsulation instead of removal” product; different purpose. |
Notice that not all “sealing” is a coating. Sometimes the most robust approach is a physical enclosure that prevents contact and impact damage.
Example of an asbestos sealer/primer (for asbestos cement): Kingfisher Asbestos Sealer & Primer
Where an asbestos survey and risk assessment conclude that encapsulation is the correct control measure, a specialist sealer/primer may be specified to help stabilise certain asbestos cement (AC) surfaces by binding surface fibres and reducing dusting. Encapsulation is still “work with asbestos” and should only be undertaken by trained, competent people using the correct controls and methods.
Kingfisher Asbestos Sealer & Primer (5L / 25L)
A water-based, solvent-free acrylic dispersion designed to penetrate and stabilise asbestos cement surfaces, helping to bind loose fibres, reduce dusting, and provide a solid base for compatible topcoats. It dries to a clear/translucent finish and is positioned as a base layer for roof coating/renovation systems.
Safety reminder: Do not sand, abrade, drill, or otherwise disturb suspected asbestos materials. If you uncover or suspect asbestos during work, stop immediately, keep others out of the area, and arrange for competent identification and next steps.
When sealing/encapsulation is appropriate
Encapsulation is generally considered when:
The ACM is in a viable state and adhering firmly to its substrate, and the plan is to keep it in place without regular disturbance. The location and environment won’t undermine the encapsulation (for example, moisture issues matter because trapped water and added weight can cause failures). Future risks are considered realistically: vibration, knocks, vandalism, maintenance access, and building movement.
In other words, an asbestos sealer is most useful when it can remain intact for years with minimal interference, while the building’s asbestos register and management plan remain up to date.
When sealing is NOT appropriate
Sealing is not a safe “shortcut” when the underlying ACM is unstable or likely to be disturbed. If a material is badly damaged, delaminating, crumbling, or likely to be impacted by refurbishment work, you may be looking at a scenario where a licensed contractor and a different control approach is required.
UK guidance for enclosing/protecting asbestos materials also highlights that certain situations are not appropriate for minor/non-licensed approaches—particularly where the asbestos is badly damaged or where the work would disturb it.
Legal and safety realities in the UK
In the UK, asbestos work sits under the Control of Asbestos Regulations 2012 (CAR 2012). Encapsulation is classed as work with asbestos and is therefore subject to those requirements. Depending on the material type, condition, and the nature of the work, it may require a licensed contractor and/or notification.
The HSE also provides “Asbestos essentials” task sheets for certain non-licensed tasks (with strict controls). These documents repeatedly emphasise training, planning, and what to do if suspected asbestos is discovered or disturbed.
If you are a homeowner: the safest assumption is that asbestos sealing/encapsulation decisions should be made with professional input (survey + risk assessment), particularly if the job involves anything beyond very limited, tightly controlled scenarios.
UK compliance and asbestos waste: the bit people often miss
Licensed work vs non-licensed work vs NNLW (high level)
In the UK, asbestos work is regulated. Broadly, work may fall into one of these buckets:
- Licensed work: higher-risk work that must be carried out by an HSE-licensed contractor.
- Non-licensed work: lower-risk tasks still requiring suitable controls and competence.
- NNLW (Notifiable Non-Licensed Work): a subset of non-licensed work with extra requirements such as notification, medical surveillance, and record-keeping.
Why this matters: “Encapsulation” can still be classed as work with asbestos, and the correct category depends on the type of asbestos material, its condition, and how likely the work is to create dust/fibre release.
Asbestos waste and disposal (don’t treat it like normal DIY waste)
Any asbestos-containing material that’s being thrown away is classed as asbestos waste — and that includes contaminated PPE, cleaning rags, and anything that can’t be properly decontaminated.
- Classification: asbestos waste is treated as hazardous waste in England and Wales (and special waste in Scotland) above the relevant thresholds.
- Packaging: waste should be securely wrapped/double-packaged and labelled appropriately (commonly using an inner asbestos-waste bag and a clear outer bag, where suitable) to prevent fibre escape.
- Don’t mix waste: asbestos waste must not be mixed with general waste “to dilute it”.
- Disposal route: disposal must be via an authorised route — for householders this is typically through your local council’s guidance (some sites accept small amounts of correctly wrapped cement-bonded asbestos; rules vary by area).
Homeowner reality check: even if you’re not an employer, you still need to prevent exposure and dispose of any asbestos waste legally. If you’re unsure about category, handling, or disposal, the safest option is to use competent professionals.
What to expect from a professional encapsulation job
A professional approach usually starts with an asbestos survey (or review of existing survey data), followed by a risk assessment. The contractor specifies an encapsulation method based on the ACM type (e.g., asbestos cement vs insulating board vs lagging/sprayed coatings), its condition, accessibility, and future disturbance risk.
From there, the job is planned to minimise fibre release and contamination spread. The emphasis is on control measures, correct product/system specification, and leaving the area in a condition that can be safely managed going forward.
Aftercare: monitoring, records, and future work
Encapsulation is not “set and forget”. After an ACM is encapsulated, it should be reassessed and then managed properly under the building’s asbestos management arrangements. That means keeping records, warning future trades, and inspecting the encapsulated surface/barrier over time for damage.
If refurbishment work is planned later, the presence of encapsulated asbestos still matters. Future work may require re-assessment and potentially different controls (including removal) depending on what’s changing in the building.
Common myths (and why they’re risky)
Myth 1: “If I seal it, it’s no longer asbestos.”
Encapsulation reduces fibre release risk; it does not remove the asbestos or the need to manage it.
Myth 2: “I can identify asbestos by colour or appearance.”
You can’t reliably confirm asbestos just by looking. The HSE specifically warns that asbestos isn’t always obvious and you can’t identify asbestos type simply by colour or appearance.
Myth 3: “A quick sand and repaint will sort it.”
Abrading asbestos-containing materials is dangerous because it can release fibres. HSE guidance for certain tasks includes clear cautions such as never sanding or rubbing down asbestos cement surfaces.
PPE for asbestos work (UK): what “good practice” looks like
Important: PPE/RPE does not make asbestos “safe”. It’s the last line of defence after the right method controls are in place. HSE guidance for non-licensed tasks also makes it clear: only carry out work if you are properly trained and have the right equipment.#
Typical PPE (non-licensed task guidance)
- Disposable Type 5 coveralls (often with a hood). Used coveralls should be treated as asbestos waste.
- Single-use disposable gloves (and dispose as asbestos waste).
- Footwear: boots are generally preferred (overshoes can be a slip risk). Choose boots without laces because they’re easier to clean.
RPE (respiratory protection): what’s usually specified
View DIY Refurbs Respiratory Protection, or view our half mask. Also available is a CAT 3 Type 5/6 Disposable Coverall.
HSE’s asbestos essentials PPE sheet recommends using suitable RPE with an Assigned Protection Factor (APF) of 20+. Common examples include FFP3 disposable respirators or a half-mask with P3 filters (subject to correct selection and suitability for the task).
- Fit testing: tight-fitting RPE should be fit tested to make sure it seals properly on the wearer.
- Facial hair: tight-fitting masks are generally not suitable with beards/stubble (a hooded/loose-fitting option may be required).
- Don’t “double up” dust masks: HSE is explicit that doubling up dust masks is useless — you need the right respirator.
Disposal and hygiene: used disposable PPE/RPE should be treated as asbestos waste. Never take contaminated overalls home, and don’t leave respirators lying around where they can collect dust.
FAQs
Are asbestos sealers a DIY product?
They’re sold in the market, but that doesn’t make them a sensible DIY choice. In the UK, asbestos work is regulated and risk-based. Even tasks that may be non-licensed still require training, correct controls, and strict methods. When in doubt, treat it as a professional job.
What’s the difference between asbestos sealing and asbestos removal?
Sealing/encapsulation keeps asbestos in place and reduces fibre release risk by applying a barrier system. Removal eliminates the asbestos-containing material from the building (with controlled removal and disposal). The right option depends on condition, location, and future refurbishment plans.
Can you paint an asbestos cement garage roof?
There is HSE guidance covering painting asbestos cement products in good condition as a controlled, non-licensed task in specific circumstances. It’s not something to improvise. If the sheets are degraded, damaged, or you’re planning refurbishment, get professional advice first.
How long does asbestos encapsulation last?
Longevity depends on the system type, environment, and future disturbance. Good systems can last years, but they still need inspection and maintenance as part of asbestos management.
Summary
Asbestos sealers are best understood as encapsulation systems—specialist coatings or barriers designed to reduce fibre release risk when asbestos-containing materials are being managed in place. They’re chosen through survey and risk assessment, they remain subject to UK asbestos regulations, and they require ongoing management rather than “one-and-done” treatment.
