Asbestos cement roof sheets still cover a large number of industrial, agricultural and commercial buildings across Ireland and Northern Ireland. Removal is expensive, disruptive and tightly regulated. Where the sheets are sound, encapsulation with a silicone coating is a lower-disturbance alternative that can extend roof life by 20+ years. Here’s exactly how it works.
Why encapsulation, not removal
Asbestos cement sheets in good condition are often best left in place and managed. Removal means specialist contractors, waste disposal, scaffold and lost trading time; encapsulation with a silicone system is typically a fraction of that cost and keeps the building operational throughout. In the Republic of Ireland the work is survey-led, risk-assessed and notified to the Health and Safety Authority (HSA) where required under the Safety, Health and Welfare at Work (Exposure to Asbestos) Regulations. The silicone membrane seals the surface, stopping fibre release from weathering and preventing UV degradation and water ingress for a further 20+ years.
When encapsulation is appropriate
- Roof sheets are sound (no major cracks, missing sections or spalling)
- Structural condition is acceptable
- Gutters, outlets and flashings are serviceable
- Building owner wants to defer capital spend on full replacement
- The asbestos survey and risk assessment support managing the sheets in place
When removal is still the answer
- Sheets are severely damaged or have failed sections
- Structural roof replacement is already planned
- Insurance or funder requirements mandate removal
- Asbestos survey identifies cross-contamination that encapsulation can’t address
We’ll give you an honest view on which route fits your roof after a free survey.
How the encapsulation works
- Pre-survey: An asbestos survey confirms the sheets are asbestos cement and that their condition is suitable. A risk assessment and plan of work follow, and where an HSA permit is required it is applied for at least 10 days before work starts (the permit requirement has applied since 30 December 2025). In Northern Ireland, the work follows the Control of Asbestos Regulations (Northern Ireland) 2012 and HSENI guidance.
- Controlled cleaning: Gentle wet cleaning with a biocidal treatment — never pressure-washed, abraded or mechanically disturbed, and never walked on unprotected, because asbestos cement sheets are fragile
- Detail work: Fibre-reinforced silicone (SF42) over end laps, side laps, fastener heads and penetrations
- Overcoat: Full GacoFlex S42 topcoat at 1.0 L/m² in single pass
- Cure + inspect: 8–12 hour cure, final inspection, warranty issue
Tax relief: Northern Ireland only
Land Remediation Relief is a corporation tax relief that may be available to qualifying Northern Ireland companies on asbestos encapsulation costs. It does not apply to companies in the Republic of Ireland. If your building is in Northern Ireland, ask your tax adviser whether your project qualifies before relying on it.
Warranty and longevity
GacoFlex S42 encapsulation on sound asbestos cement carries a 20-year manufacturer-backed product warranty. After the warranty period, a simple silicone recoat (no strip) extends performance for another full cycle. Over a 40-year asset hold, the encapsulation + single recoat route is dramatically cheaper than removal + new roof + replacement cladding.
Got an asbestos cement roof? Full asbestos encapsulation guide or email info@duratite.ie for a free survey.