Do I need my roof coated?

[bunnymeme]

I paid a company to pressure wash my roof and he said I did not need to bother with coating it, it looks a bit grey, what do you think? I have been quoted £900 for coating 85sqm and I am tempted to hire some ladders and paint the tiles myself for that price but worried that I will damage the roof. What do you think? Any recommendation on tile paint? Do I need it coated professionally?

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[noseall]

Tiles are made of concrete and not timber.

They do not need painting nor will they benefit from it.