Xtreme Moss Stop: Our fast-acting moss killer will not only kill unsightly moss, algae, and lichen, it also acts as a preventative formula and stops moss or algae growth returning. The advanced moss killing formulation will swiftly kill moss on roofs, driveways, patios and paths. Suitable for use on concrete, tarmac, astroturf and all types of natural stone, it can keep your outdoor areas looking pristine at all times. As a preventative, it will keep working for over 12 months after application to help stop any re-growth of moss and algae. Lasting Protection: Xtreme Moss Stop will help protect your property from the annoying regrowth of moss, algae and lichen. It will not only kill moss, it will also leave a protective film on the surface after application to help prevent the regrowth of moss in the future. You can then enjoy your outdoor spaces free of any moss growth and avoid the need for frequent reapplications as seen with other weaker moss killing formulations.