SmartSeal Roof Clean Xtreme - 2 x 5L - Powerful, Fast Acting Roof Cleaner. Concentrated Growth Killer For Roofs, Algae Remover For Concrete, Slate And Clay Roof Tiles

I would reccomend this for moss and dirty roof tiles. Just spray and let it work. Next thing you will see new looking roof tiles.

Mine needed two sprays

Not had chance to apply yet but quietly confident. At a max 1:1 dilution it is expensive, with some quoting 25:1. High expectations.

This is amazing. Scraped off the moss and lichen with a wire brush . Sprayed onto our tiles about 3 hours later I washed it off. They look like new !!!

Do as good as I was expecting. Took a lot of scrubbing to clean the lichen off the tiles.

Did a great job on a North facing roof. Delighted with the results.

Cleans up tiles beautifully. But don’t be tempted to wire brush too early. Good at destroying the really annoying white spot/lichen. Quite a strong smell of ammonia - best to wear mask and it will temporarily stain lead flashing and will wreck your clothes if windy. Acts like bleach a bit. Had to buy some new trousers!

Tried this product on some spare tiles that were marked and stained. It had no effect on the tiles at all. Tried it diluted and also neat and no difference.

It does the job but it looks like is just bleach. .. unknown concentration as the labe does not state the content... or I didn't find it.