Asbestos cement vs fibre cement on farm roofs — solar PV implications

A common source of confusion on UK farm buildings: is the roof cladding asbestos cement (pre-2000, mostly), modern fibre cement (post-1999), or a profiled steel sheet that simply looks similar from the ground? The answer determines whether rooftop PV can proceed directly, whether re-roofing is required first, and which contractor specialisms are needed. Here’s the practical 2026 guide.

The regulatory history

Asbestos cement (AC) was the dominant agricultural roof cladding from the 1950s through to the late 1980s. The Asbestos (Prohibitions) Regulations 1985 banned blue and brown asbestos use in new buildings; the Asbestos (Prohibitions) (Amendment) Regulations 1999 banned the remaining white asbestos (chrysotile) types from November 1999. Any farm building roof installed before approximately 1999 has a high probability of containing AC cladding. Buildings constructed from 2000 onwards use either modern fibre cement (cellulose and polymer fibres replacing asbestos), profiled steel sheet (Plastisol-coated typically), or composite panel systems.

How to identify what you have

Identifying cladding by visual inspection alone is unreliable — asbestos cement and modern fibre cement look identical from the ground. The definitive identification is a sample test by a UKAS-accredited laboratory (typically £40–£80 per sample). Without a sample test, the safe presumption is: any building constructed pre-2000 is treated as asbestos cement until proven otherwise. We arrange sample testing as part of our standard structural survey on any farm building over 25 years old.

What asbestos cement means for solar

Under the Control of Asbestos Regulations 2012 (CAR 2012), no drilling, fixing, load-imposition or significant disturbance is permitted on asbestos cement cladding. There is no derogation for solar PV. Any rooftop PV install on a building with AC cladding requires one of two approaches: (1) strip-and-reclad, removing AC under HSE-licensed conditions and installing new cladding before any PV work; or (2) total roof replacement as part of the combined PV project. Either approach must be carried out by HSE-licensed asbestos contractors and notified to HSE via a 14-day Asbestos Removal Notification before work begins.

What modern fibre cement means for solar

Modern fibre cement (made from cellulose and polymer fibres, no asbestos) can take rooftop PV directly, provided the structural frame and purlin spacing meet the dead load requirements. Modern FC products from manufacturers like Eternit (Cembrit), Marley Eternit, and Marleycor are designed to similar specifications as Plastisol-coated steel and typically support rooftop PV racking without issue. Surveys still required: structural frame assessment (does the steel portal support PV dead load?), purlin spacing assessment (do panels span between supports correctly?), and roof condition assessment (any cracks, missing fixings, structural concerns?). A standard survey costs £400–£1,200 per building.

Combined re-roof + PV economics on AC buildings

For pre-2000 AC-clad farm buildings, the combined re-roof + PV business case is well-established. HSE-licensed AC removal costs £30–£50/sqm depending on building size and disposal route. Profiled steel re-cladding costs £45–£80/sqm installed. A 2,000 sqm AC-clad livestock shed typically costs £150,000–£260,000 to strip and re-clad before any PV work. PV install on top adds the standard £700–£950/kW depending on system size. Combined total: typically £350,000–£500,000+ for a 200–300 kW system on a re-clad large livestock building. Despite the high capex, the PV business case routinely pays for 60–100% of the re-roof over the 25-year system life — turning a deferred maintenance liability into an income-generating asset.

Picking a re-roof contractor

For the re-cladding scope (after AC removal), specify: profiled steel or composite panel cladding (Plastisol-coated for 40-year service life); roof pitch maintained or adjusted for optimal PV orientation (typically 5°–35° south or east-west facing); purlin spacing optimised for modern PV racking (typically 1.2–1.8m centres); structural reinforcement if frame upgrades are required (rarely needed on post-1970 portal frames, sometimes needed on older bolted-truss structures). The cladding contractor should coordinate directly with the PV installer to ensure compatible mounting systems.

Picking an HSE-licensed asbestos contractor

HSE publishes the current asbestos licence holders register at hse.gov.uk. Look for: current licence (not expired or revoked); recent track record on agricultural AC removal (not just commercial/industrial); insurance cover at the appropriate level (typically £10m public liability minimum); waste consignment procedure including proper hazardous waste documentation; willingness to coordinate with the PV installer on shared scaffolding, access roads, and welfare facilities. The best combined projects use a single principal contractor coordinating the asbestos team, cladding installer, and PV installer under one programme — saves £20,000–£50,000 versus sequential delivery.

What to do if you’re unsure

If you have a farm building you’d like to put PV on and you’re unsure whether the roof is AC, modern FC, or steel: book a structural survey including sample testing. We arrange this as part of our standard feasibility process for any pre-2000 farm building, with sample results back from the lab in 5–10 working days. Once the cladding is positively identified, the project path becomes clear — direct PV on FC or steel, combined re-roof + PV on AC, or a wider conversation about which buildings on the holding are best-suited to PV first.