Solar PV - Farmers set to get 'free' asbestos roof replacement

Working on asbestos cement roofs adds cost for solar PV installations due to health & safety and insurance. The installation methods are also more costly as an additional sub structure is required to support the solar panels above the asbestos roof.

Corrugated sheet roofs constructed before 1984 are extremely likely to contain asbestos, as alternatives generally only started to become available in that year. Asbestos cement was no longer supplied to the UK market from 1999, so any buildings constructed since then should be fibre cement rather than asbestos based. If the roof dates from between 1984 and 1999 then it may contain asbestos. Sample analysis can definitively identify asbestos, but this is not always practicable. The manufacturer's mark on profiled sheets, which is indented into the overlap of the side lap roll, will normally give, amongst other things, a code name of the manufacturer and the date of manufacture.

However, the good news is that this cost of stripping the old sheets and replacing with good quality new coated steel sheets would normally be covered by the saving in installation costs so the farmer gets a new roof and improves the environment.

Old asbestos sheets are heavy, amounting to 15kg per m2 or more. Solar PV panels will place a very similar loading on the roof and so the replacement option makes sense from a structural standpoint too and will help extend the life of the building.

The figures are as follows. Hestia estimates the cost of replacing asbestos roofing sheets with high quality coated steel sheets on a typical barn at around £25 per m². The installation costs for a high efficiency Solar PV installation would be in the region of £370 per m² for a steel sheet roof and £400 per m² for an asbestos roof, making it cheaper to install a completely new roof compared to installing on the old asbestos roof - problem solved!

Hestia's Farm Installations will return around 12% per annum in feed-in tariffs and electricity savings and considerably more if capital allowances can be utilised.

Operating since 1993, Hestia is one of the most established renewable energy firms in the UK. For further information please contact us on 0800 043 2410 or info@hestiaservices.co.uk.

A typical asbestos roof grain store.jpg