wrote:

Copper is best.Fix a single strand along the roof above the moss and
through time it will kill it off.Best source for copper wire is a bit
of 2.5 single core and strip the insulation off.

Oddly enough, I was intending to do exactly that to my garage roof later
this week. However the roof is corrugated. Clearly, the copper wire
needs to follow the contours, so as to lie in the valleys and contact
any rain water, but what's the best way of fastening it ?