I'd be grateful for your trusted opinion on the following, before I go and do something I shouldn't.
I built this sandstone wall (pictured) in my garden last year and prior to putting down a new lawn I want to spruce up said wall and get rid of the green mould (or whatever it is) that's appeared on some of the blocks.
Should I use a purpose cleaner or bleach or something, or just give it a good blast with the power washer and a stiff brush? Also, should I then coat it with a sealer to protect it from further staining? I know they sell cleaners & sealers in Woodies and the likes but don't want to use anything that might damage the stone.
Ditto for my patio (also pictured) that's a few years old and that I unfortunately failed to maintain and so has gotten to look a bit drab with bits of moss growing in the jointing. I don't need it to look like new - just something to bring it back to life a bit.
Thanks in advance.
D
