Cleaning roof tiles, questions

Concrete tiles dont need sealing. Pressure washing only has the advantage of cleaning them, but will also cause a lot of water ingress. Moss can be prevented with copper wire.

NT

What thickness of copper wire as I see stuff for making jewellery from

There's a comment on moss in the sixth paragraph of this article:

Moss blocked the gutter,s the water from the gutters overflowed and ran down the wall staining the wall red in some parts (on a white painted building) where it contained red dust from the roof tiles. Plus its a pain when there is a lot and continually falling below.

And there am I deliberately buying lichen and moss covered old clay tiles by the thousand to keep the weathered old look! 7000 arrived today!

AWEM

What does it save you, six months of weather?

No, a lot more than that. To age them to as these are would take decades. They take on a darker shade, but subtly varied across the roof. New pegs or nibs shout at you for years

AWEM

Fair enough, if it's all coming loose. As NT has said, water will get under the tiles with pressure washing. I'd just go over it with a brush.

Is it true that painting them with yoghurt or buttermilk encourages moss to grow? Or do you just end up with a stinky roof?

Copper wire is on my list of jobs, when I get the scaffold up to repoint and paint the walls!

Diluted cow pats are favoured locally, sprinkled on with a watering can and rose, but I've not had to do that yet !!

AWEM

In message , Andrew Mawson wrote

Or a quick coat of yoghurt

Doesnt sound too robust! 1mm from mains cable should do

NT

I recall one job where they sprayed liquid "fertiliser" on them... (that and mixing a few of the old tiles in with the new). Looked pretty good within a couple of years.

Thanks NT

A bit of both. Anything that provides a bit of stick'um and nutrients for lichen and moss spores will encourage them to get started.

It also depends if you have a real fire and how many birds visit your roof and TV aerial. The latter now being almost redundant but not worth the effort of removing it. I much prefer my roof with lichen on - it breaks up the monotony. Life is too short to clean roofs! I expect the main result of cleaning will be to damage the roof and shorten its life.

I only remove moss that is threatening to fall off anyway and block the gutters. The lichens and other markings show true age. It would be an act of vandalism to pressure wash them off - not sure it would work either I have a feeling they etch into the clay for nutrients.