Roof Moss Removal — Rockbrook Road, St Kilda East

Two hundred square metres does not sound like a full day until you understand what moss is doing up there. It is not sitting on the tiles like dust — it holds water against them, and a roof that stays wet grows more of it, gets heavier every winter and stops shedding water the way it was built to. The volume is the other half. Cleared moss has to go somewhere, and on a roof this size that is a large amount of wet organic matter, all of which lands in the gutters if nobody plans for it.

Most of what a roof like this carries comes off in the visit. The soft, cushioned growth sitting in the laps and valleys lifts as soon as it is wet, and the film across the tile faces goes with the rinse — which is why this job has a genuine before and after rather than a promise about six weeks' time. What is bonded deeper into the terracotta keeps releasing for weeks afterwards as the roof wets and dries. That part cannot be hurried, and trying to hurry it with pressure takes the glaze off the tile along with the growth. Clearing came first, then treatment across the whole area including the valleys and the ridge line, at low pressure with contact time doing the work. Ten hours for two people is what two hundred square metres takes when the roof is not being blasted. Gutters last, because everything that comes off a roof lands in them.

• Two hundred square metres of roof cleared of moss
• Treatment applied across the full area, valleys and ridge included
• Low pressure throughout, no lance held close to the tiles
• Gutters cleared after the roof rather than before it
• Before and after photographs supplied

• Growth off the tile faces, terracotta colour back across the whole roof
• Valleys running clear rather than holding water and debris
• Gutters clear of everything that came down off the roof
• No cracked or displaced tiles left behind
• Deeper-bonded growth continuing to release over the following weeks