Since we have been cleaning roofs of homes in London for years, this is the query we are asked the most. The solution is.
Slate and clay roof tiles are two types of roof tiles that may be pressure washed. However, some ancient concrete tiles should not be pressure washed because the surface may be damaged, making the tile more water-absorbent and occasionally exposing a different colour of concrete underneath.
Is the roof structurally sound enough to be cleaned?
Despite the grime and moss on your roof, are all the tiles in their proper locations, and is the pointing on the ridges still strong?
If your roof is structurally sound, the pointing is solid, and there are no apparent water entry points like cracks or missing tiles, you can pressure wash your roof and its roof tiles.
In order to determine the best method for restoring each roof, whether it be pressure washing, soft washing, steam cleaning, or sometimes just removing the moss and treating the roof with a biocidal wash to help keep the roof clean and moss-free for longer, we inspect each roof to determine its condition and the type of tile.