Paving stones are a beautiful way to create a driveway or walkway on a property in lieu of concrete. Stronger than concrete and easier to repair, it is no wonder so many people turn to paving stones as a way to enhance their home and its value. Moss growth on paving stones can be a problem, however. Moss makes walkways slippery and can, over time, cause discolouration and damage, making it necessary to remove it.
Pressure wash the area. Using water pressure without chemicals or soaps, the bulk of the moss can be removed quickly. This should also allow you to get in between stones if they are not locked together, leaving the moss nowhere to hide.
Change the environment. Moss grows best in wet and shady areas. To reduce moisture and shade, remove overhanging branches if possible and anything that will hold moisture, such as piled leaves, as soon as possible.
Treat the area with chemical moss killer. There are a number of different chemicals that can be used to kill moss, including household bleach. Be aware some of them stain and most of them will kill other plants as quickly as they will kill moss. Read and follow the instructions carefully for best results.
You can rent a pressure washer or have your walkway professionally washed. Rental is cheaper but more time consuming. Making changes to the overall environment helps to reduce the need for repetitively removing moss. Regular household bleach can be used to kill moss. Used properly, this does not stain stone, though it will stain clothing. A 1-to-1 solution can be sprayed on for 30 seconds and then rinsed. Though it is easy to use a spray bottle on smaller areas, use a backpack sprayer to speed up the chemical application process.
Take care when trimming overhanging branches because there is a chance of injury or property damage. Chemical moss killers can stain stone and kill other plants. They are almost never safe to introduce into the water supply. Keep this in mind when choosing what kind of chemicals to use on your paving stones as cross-contamination is easy with both sprays and run-off.