This is often a question we are asked by our clients, the answer is….
Some roof tiles are suitable for pressure washing such as slate and clay. Some older concrete tiles are less susceptible for pressure washing.
This is because the surface of the tile can be damaged leaving the tile more water absorbent.
Sometimes presssure washing will speed up the removal of a top coloured layer to reveal a different coloured concrete below.
This top coloured layer of the tile is often the tiles water repellent layer. When this is lost the tile will hold more water promoting growth of organic matter such as moss and algaes.
However, this also happens naturally over time to these type of tiles. This can often be seen when some moss falls from the roof revealing a different colour. Often a concrete or bage colour. If you look at the reverse of th e moss you can sometimes see the coloured granules from the top layer of the tile. This can also sometimes be seen lying in guttering .
The solution for this is to have the roof cfully cleaned removing all moss, algae and organic growth and then have the roof recoated with a colured roof coating. Not only will this provide a uniform appearnace with the colour but the coating will also provide that water repellency that the tile has lost over time.
To find ut more about roof coatings and sealing click here.
Is the roof in good structural repair?
Your roof may be dirty and covered in moss but are all the tiles in the correct place and is the pointing on the ridges still strong?
You can Pressure wash your roof if it is in good structural condition, the pointing is strong and there are no visible entry points for water such as cracks or missing tiles.
With every roof clean we inspect the roof to establish the condition of the roof and the type of tile.
We inform our client of the best process for restoring their roof whether that is 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.
If the roof is showing evidence of colour loss and patchiness then we would recommend having the roof recoated afer cleaning.