Modern tiles like that - 150 bar
What problems ?
Most of the horror stories are either US based where people p/w wooden shingles or roofs with felt
the other is people not cleaning from above and firing the jet of water up into the tiles and lifting them
Must have done well over 100 roof cleans now - clay - cement - slate with all sorts of profiles - where poss we don't walk the roof - that makes a big difference
Darran