The natural fouling of our CoolRoof solution is limited and its cleaning by rainwater is facilitated by the action of the TopCoat. However, some microorganisms and dust will manage to settle on it, especially on rough substrates such as bituminous membranes self-protected by flakes. To maintain performance and improve durability, it is therefore recommended to clean the membrane annually with low pressure water, if necessary with the help of a brush. This will extend the life of our CoolRoof and restore the initial reflectance annually.