Corrugated and trapezoidal profile metal sheeting is the most common roof cladding on UK industrial and agricultural portal frame buildings. Solar PV installation uses hook-bolt fixings into the sheeting corrugations, transferring loads through the sheet to the purlins below. The structural assessment must verify purlin capacity to carry the array dead load at the actual fixing spacing.
Older corrugated metal roofs may have experienced corrosion, particularly at fixings and in ponding areas. A drone roof condition assessment can identify areas of significant degradation that would compromise new PV fixing integrity. Heavily corroded purlin or sheeting sections identified during assessment may require replacement before array installation proceeds.