Powwerhosing tiles

[do_it_yourself]

Hi, my roof is in a state with moss and debris collated over many a year.

I was thinking about powerhosing the roof to lift the moss and give the tiles a new lease of life. They are about 30 years old and are a traditional clay type.

Is there anything I should do after powerhosing? Do i need to reseal or paint them?

 

[Xenon]

Just watch where you stand, they're expensive if handmade clays, hose downwards.

They've been there 30 years without a coating....

 

[oldbutgood]

You can power wash but a 30 mtr hose is good so the machine stays on the floor. A 6ft lance and turbo nozzle helps. Concrete tiles are designed to last 35-40 yrs (Marley archive), and need sealing once cleaned, otherwise you are giving moss spors a nice new bed to lie in. Wash down with anti-fungal moss killer, and seak with water based acrylic.
Rosemary tiles (ie clay),last longer BUT rot from the back, so the front may look OK but they crack for fun once walked on. Take one or two out near to the gutter and inspect the back. The only sealant for clay is solvent based and not nice to use. Some roof-coaters offer sealants for rosemary but not recommended to use without primer.Really this is a specialist job and can cost £25 per mtr. roof-coaters are out there as this trade is bigger now than ever before. (There are some doubters out there).