The short answer
- You have three options for an asbestos cement roof: leave it in place and monitor it, encapsulate it, or remove it. HSA guidance recognises all three, and the right one depends on the sheets' condition and what you need from the roof.
- Undisturbed sheets in fair condition are low risk. HSA guidance says asbestos cement weathers slowly, and removal can itself create the greatest risk of significant exposure.
- Encapsulation seals the sheet in place. Externally it is roofing foam plus a silicone, urethane or polyurea top coat. Internally it is closed-cell spray foam on the underside. Both routes can add waterproofing, insulation and condensation control without cutting or drilling the sheets.
- From 30 December 2025, asbestos work under the Exposure to Asbestos Regulations 2006–2025 needs an HSA permit. The contractor notifies the HSA at least 10 days before work starts, with a plan of work, a site-specific risk assessment and training records.
Why asbestos cement roofs are still everywhere
Asbestos cement sheeting was used on agricultural sheds, industrial units, warehouses, garages and public buildings for decades. It was cheap, durable and fire-resisting, and a great many of those roofs are still in service across Ireland. Placing asbestos products on the market, and using or reusing them, is now prohibited under the EU REACH Regulation. The existing roofs, though, are managed where they are.
Owners usually start asking questions when something changes:
- the roof starts to leak through cracked sheets, failed laps or corroded fixings
- condensation drips inside onto stock, machinery or animals
- the building is being sold, let, refinanced or converted
- an insurer or lender asks about the roof
- moss and lichen make the roof look worse than it is
The good news is that in many cases the answer is not "rip it off". The rest of this guide explains why, what the law now requires, and how to choose.
The law in the Republic: Exposure to Asbestos Regulations and the HSA permit
Work with asbestos in the Republic of Ireland is governed by the Safety, Health and Welfare at Work (Exposure to Asbestos) Regulations 2006–2025. That is S.I. 386 of 2006, as amended by S.I. 589 of 2010 and S.I. 632 of 2025. The 2025 amendment brings in the requirements of EU Directive 2023/2668. The Health and Safety Authority (HSA) enforces the regulations and has published a 2025 Code of Practice to go with them.
The permit system from 30 December 2025
The biggest practical change is that a permit must be obtained in advance for work with asbestos, through the HSA's notification process. In outline:
- the notifier submits the HSA's 2025 notification form
- a plan of work is submitted
- a site-specific risk assessment is submitted
- training records for the people doing the work are provided
- the notification period is 10 days, so it is made at least 10 days before work starts
- once processed, the HSA issues a unique permit number for that notification, and work cannot start before it is issued
The HSA's own guidance lists encapsulation of asbestos cement roofs with a chemical-based solution among notifiable work activities. It notes that such work normally involves a surface pre-clean and significant time on a fragile roof. Plan for the permit in your programme. It is not a formality, and a contractor who proposes to "just get on with it" is a contractor to avoid.
Before any work: the survey
Before refurbishment or demolition work, the asbestos-containing materials affected need to be identified by a refurbishment/demolition asbestos survey. For a roof, that confirms what the sheets are, their condition, and any other asbestos-containing materials such as ridge pieces, closures, gutters or debris in the building. The survey, the risk assessment and the plan of work are the basis for choosing an option, not an afterthought.
How risky is an asbestos cement roof?
HSA guidance is clear that asbestos cement is a different risk from sprayed coatings, lagging or insulating board. The fibres are tightly bound in the cement matrix. They are released when the material is mechanically damaged, for example by drilling, sawing, sanding, breakage or abrasive tools, or by weathering. The guidance states that asbestos cement roof sheets used externally weather slowly, and that the low rate of fibre release means the risk of exposure is extremely low if the sheets are left undisturbed.
The same guidance warns about the things that do raise the risk:
- Fragility. Asbestos cement is a fragile roof material that cannot take a person's weight. Falls through fragile roofs are a serious risk in their own right, whatever the asbestos position.
- Aggressive cleaning. Dry scraping and wire brushing are not recommended. High-pressure water jetting can also drive debris between the sheet overlaps and cause leaks. Moss and lichen growth is normal and does not damage the material.
- Removal itself. HSA guidance notes that removing existing asbestos-containing materials can present the greatest risk of significant exposure.
- Fire damage. Heat can make asbestos cement rupture violently and scatter debris. Fire-damaged sheets are a different problem needing specialist advice.
So the starting point for a sound roof is not panic. It is a survey, a condition assessment and a decision.
Not sure what your roof is made of?
Send a few photos and the building address. We will arrange a free survey and tell you plainly whether encapsulation suits it.
Leave, encapsulate or remove: comparing the options
| Leave in place and monitor | Encapsulate | Remove and replace | |
|---|---|---|---|
| Best for | Sound, dry, undisturbed sheets | Sheets that are sound enough to hold a coating but leak, drip or need upgrading | Badly damaged, fire-damaged or structurally failing sheets; demolition; redevelopment |
| Disturbance of sheets | None | Controlled surface preparation, no cutting or drilling | Every sheet lifted, handled and disposed of |
| Fixes leaks | No | Yes: external route adds a waterproof top coat | Yes: new roof |
| Adds insulation | No | Yes: roofing foam externally, closed-cell foam internally | Only if the new roof is insulated |
| Controls condensation | No | Yes, especially the internal foam route | Depends on new roof design |
| Building in use during works | Yes | Often: external route works above an occupied building | Usually disrupted; interior exposed to weather |
| Waste | None | Minimal (preparation waste handled as asbestos waste) | Full roof of hazardous waste to licensed disposal |
| HSA permit | Not for monitoring alone | Plan for it | Yes |
General comparison. Your asbestos survey, risk assessment and HSA process decide what applies to your roof.
HSA guidance lists the questions to ask before choosing encapsulation. We use them in every survey:
- What type of asbestos-containing material is it, and what condition is it in?
- Is the substrate sound enough for the encapsulant to adhere?
- Could water getting in through the substrate add weight and make the encapsulant fall away?
- Could further damage come from traffic, birds, rodents or vandalism?
- Is there enough access for the process to be done properly?
- Will the encapsulant keep the thermal and acoustic performance the building needs?
- Would encapsulating simply put off a removal that will be needed later, at more cost?
If the honest answer to the last question is "yes", for example because the building is due for demolition in two years, we will say so.
How encapsulation works: the external and internal routes
There are two encapsulation routes. The client chooses which, and some buildings get both.
External encapsulation: roofing foam and a waterproof top coat
- Preparation. Controlled, low-pressure cleaning and treatment of organic growth, following the plan of work. No dry scraping, wire brushing or high-pressure jetting.
- Roofing foam. A closed-cell roofing foam, from Gaco or Purios HR, is sprayed over the top face of the sheets. It encapsulates the surface, bonds the sheets and laps together, adds rigidity and insulates. Purios HR has a declared λ of 0.0233 W/m·K, a minimum density of 50 kg/m³ and a compressive strength of at least 300 kPa. It needs a clean, dry substrate, substrate and air temperatures of at least 15 °C and relative humidity no higher than 60%. In an Irish climate that means planning the application window carefully.
- Top coat. A liquid waterproof top coat goes over the foam. It can be silicone (GacoFlex S42), urethane (GacoFlex U91 base coat with U92 top coat) or polyurea. S42 is a single-component silicone roof coating. It carries a 20-year manufacturer-backed product warranty at 0.90 mm wet film in a single pass. Top coat selection depends on the substrate, the exposure and whether the roof will take foot traffic.
Internal encapsulation: closed-cell spray foam on the underside
Closed-cell spray foam is applied to the underside of the sheets from inside the building. Enverge Nexseal 2.0 is used for build-ups under 50 mm and Enverge Nexseal LE for thicker build-ups. The foam self-bonds to the sheet, so nothing is drilled or fixed through the asbestos cement. That is the key difference from board, batten or membrane lining systems, which all need fixings through or beside the sheet. The foam seals the underside, insulates, and stops the condensation that forms on cold sheets. It is a complete option on its own, not half of a two-sided job.
Why no fixings matters: every hole drilled in an asbestos cement sheet is disturbance of an asbestos-containing material. A self-bonding foam avoids it completely.
Choosing the right option for your building
Farm sheds and agricultural buildings
These often have the oldest asbestos cement roofs and the worst condensation. Internal closed-cell foam solves the drips over livestock, feed and machinery. External encapsulation solves leaks. Our farm building condensation guide covers the ventilation side, which must never be sealed up.
Occupied warehouses and industrial units
External encapsulation lets the business keep trading under the roof while the work happens above. Removal usually means stripping stock and machinery out of the building, or covering it, and working with an open roof.
Buildings being sold or refinanced
A survey report and a documented encapsulation with a manufacturer-backed product warranty answer the questions buyers and lenders ask. A roof that "might be asbestos and might leak" does not.
When removal is the right answer
Choose removal when sheets are broken, heavily degraded or fire-damaged, when the structure underneath has failed, or when the building is being demolished or redeveloped. It is also right when encapsulation would only delay an inevitable removal. Encapsulation is not a way to avoid dealing with a roof that has reached the end of its life.
We cover buildings across the Republic, including County Cork, County Tipperary, County Meath and County Galway, through approved installers who cover each county.