UK farm roof types suitable for solar PV

Not every farm building roof is suitable for retrofit solar PV. The cladding material, structural condition, age, and integrity all factor into whether direct PV is possible or whether re-roofing is needed first. Here’s the 2026 UK farm roof compatibility assessment.

Profiled Plastisol-coated steel (post-2000)

The dominant modern UK agricultural roof cladding. Profiled steel sheets coated with Plastisol (or HPS200 from Tata Steel, or comparable from other manufacturers). 40+ year service life when properly installed and maintained.

PV compatibility: excellent. Direct PV installation using standard racking systems (Schletter, Renusol, K2). Penetrating fixings through the rib peaks with proper EPDM sealing.

Structural capacity: typically adequate for PV dead load without reinforcement. Confirm with structural engineer on installation.

Most common case for UK farm installs from 2010 onwards.

Fibre cement (post-1999)

The modern asbestos-free cement cladding. Cellulose and polymer fibres replacing asbestos from November 1999. Manufactured by Eternit (Cembrit), Marley Eternit, Marleycor and others. 30-40 year service life.

PV compatibility: good. Direct PV installation using standard racking with specific fibre-cement-rated fixings (typically self-drilling stainless steel screws with EPDM washers).

Structural capacity: needs verification per building. Fibre cement is heavier than profiled steel; structural assessment important.

Common on UK farm buildings constructed 1999-2010.

Composite insulated panels

Factory-engineered sandwich panels — Plastisol-coated steel skin both sides over insulating foam core. Manufacturers: Kingspan, Tata Wandfix, Trimo Trimoterm and others. 40+ year service life.

PV compatibility: good with specialist mounting brackets. Brackets clip into the panel ribs without penetrating the insulation core. Schletter and Renusol both offer composite-panel-specific systems.

Structural capacity: typically excellent — composite panels are engineered for high loads.

Most common on UK farm buildings constructed 2010+ where insulation is a primary requirement (dairy parlours, pig finisher houses, glasshouses).

Membrane roofs

Single-ply or built-up membrane systems on flat or low-pitch farm buildings. Less common on agricultural buildings but increasingly used on dairy parlour extensions and equestrian arena complexes.

PV compatibility: good with ballasted mounting systems (no penetration of membrane). Some systems support pole-mounted PV with appropriate membrane-compatible fixings.

Structural capacity: needs verification — membrane roofs are typically lighter construction than profiled steel.

Common on commercial-style farm buildings, particularly newer dairy and food-production facilities.

Asbestos cement (pre-2000)

Dominant agricultural roof cladding from 1950s through 1999. Contains chrysotile asbestos fibres in cement matrix. 40+ year service life but increasingly past nominal life on pre-1985 buildings.

PV compatibility: NO. Under Control of Asbestos Regulations 2012, no drilling, fixing, or load-imposition is permitted on asbestos cement. PV installation requires HSE-licensed removal and re-cladding first.

The combined re-roof + PV business case is well-established. HSE-licensed AC removal £30-£50/sqm; profiled steel re-cladding £45-£80/sqm; then standard PV on the new roof.

For most pre-2000 UK farm buildings, asbestos sample testing is the first step in any feasibility assessment.

Corrugated galvanised iron (pre-1980)

Older agricultural roofing — galvanised steel without Plastisol coating. 50-60+ year service life but typically past nominal life on most buildings.

PV compatibility: poor. Surface usually weathered, fixings deteriorated, structural frame often compromised. Re-roofing usually required before PV.

Tile or slate roofs (rare on agricultural buildings)

Unusual on working agricultural buildings but occasionally on listed farmhouses or converted barn complexes.

PV compatibility: requires tile-specific mounting hardware (in-roof or on-roof systems). Listed buildings require Listed Building Consent for any visible roof modification.

Polythene polytunnels

Clear polythene over steel hoops. Replaced every 4 years typically. Not suitable for direct rooftop PV (polythene won’t take the load; replacement cycle conflicts with PV permanence).

PV alternatives for polytunnel operations: ground-mount adjacent to the polytunnel; agrivoltaic raised PV structure above the polytunnel (semi-transparent panels, longer-term commitment).

Roof structural assessment

Regardless of cladding type, every farm PV install requires structural assessment of: frame condition (steel-portal post-1970, bolted-truss older); purlin spacing and depth (modern 1.2-1.8m centres, 175-225mm depth); cladding fixing pattern; visible structural defects.

We arrange structural assessment as part of every site survey — typically 1-day on-site by qualified engineer, with detailed report 5-10 working days later.

Roofs we’d advise against PV

Some roof situations where we’d recommend against PV:

• Buildings scheduled for demolition or major use change within 10 years (PV economic life not achieved)
• Buildings with severe structural deterioration (frame corrosion, purlin sag beyond reinforcement scope)
• Roof orientations producing very poor PV yield (north-facing dominant, severe permanent shading)
• Buildings on tenancies with less than 10 years remaining and unclear renewal

For most modern UK farm buildings, PV is straightforward. For pre-2000 buildings with asbestos cement, combined re-roof + PV is the standard solution. For everything else, the site survey confirms compatibility before commitment.