I've got a patio made from black limestone slabs, it's been down about a year. I used some moss killer on the grass and about a week later I saw these orange stains on the slabs near the grass - see below.
Has anyone got any suggestions as to what I can do about this?
Also do I need to seal these? If anything gets split on them apart from water the mark stays for ages before going. For example the Mrs decided to stand on one whilst spraying sun tan lotion on her feet - I've still got feet shaped stains two weeks later!
Use a non-acidic rust remover - Rust-ex or PaveTuf Rust Remover - but, as ever, trial a small, dicreet corner first to ensure there is no adverse reaction.
