Cleaning concrete tile roof

Fine Cheers

Alot of moss building up on brown concrete flat tiled roof, 4 bed detached, hipped all around. Almost a pyramid. Just wondering about best route to go. I have heard arguments for and against power washing. Chemical spray another option. I have a power washer and could borrow a mobile scaffold unit but just wondering is this the way to go. Fascias and soffits need doing too but want to get roof sorted first.

ElderWanderer

Power washing is a bad idea, as it can damage the roof inside & out.

The best choice is to brush the major crap off the roof, followed by a biocide to kill the moss that's left. Leave it for a week, then take off the dead moss by brushing again. Seal the tiles so that that moss can't get a grip on them, so it doesn't come back any time soon. You have to do it all in dry weather, if at all possible.

MicktheMan

I've used a product called Mosgo before on my roof and found it great. Just dilute and apply with a knapsap sprayer and leave it to work.

Calahonda52

I would just use 10% diluted Chlorus, c 22 euro for 25 litres, so 250 litres mixed, from your local agri supplier and spray and leave, you don't want to brushing tiles on the roof
dangerous activity and also asking for cracked slates,
you could also experiment with the power sprayer in wash mode only and let it mix the chlorus.
power washing at full pressure is not recommended