Solar Panels on Slate Roofs

Why slate needs more care

Slate is thin, brittle and fixed with nails rather than hung on a nib. Anchors have to be placed carefully and the slate dressed or replaced around them. A rushed job on slate shows up as cracked slates and, eventually, water ingress.

The Glasgow context

Much of the older housing here is sandstone tenements, interwar and post-war semis, and a large stock of ex-local-authority housing, with natural and Welsh slate on the tenements, concrete tile on the later stock. Tenement roofs are usually shared, so a flat owner normally needs the agreement of the other owners in the close before an array can go on.

Fixing detail

Anchors fix to the rafters, with the slate above dressed over the bracket or replaced with a lead soaker. Done properly there is no reliance on sealant to keep the water out.

Age and condition

Old slate can be sound for decades more or can be at the end of its life with failing nails. A survey should include a genuine assessment of that, because it changes the sequencing of the whole job.