Leaves, tree flowers, pine needles and other detritus should not be allowed to remain on the surface for any length of time. If this happens they rapidly rot down forming a drainage-inhibiting ‘skin’ within the surface, and providing a growing medium for algae, moss and weeds which may allow moisture to be held within the surface, which may cause issues during cold / freezing conditions due to expansion /contraction.
Periodic cleaning by hosing down or Light Power Washing and copious amounts of water with a stiff brush should be all that is necessary to remove pollution and surface debris.
