Cementaid has released Driwal P6, a water-repellent reactive silicone component with the P6 modifier dissolved in a penetrating solvent. Flooded onto masonry or concrete it penetrates several millimetres into the surface, delivering the water-repelling components deep into the substrate before drying invisibly. They is no physical film or darkening effect, preserving the masonry’s natural appearance, which is able to “breathe”.
Unmodified silicone treatments may only last two or three years before requiring re-application. Driwal’s calcium fixing P6 formula chemically binds the silicone components to calcium compounds within the masonry surface, so it has a much longer life. The long-term water repellency, coupled with its anti-mould fungicidal action keeps the surface dry and protects against mould or fungal growth.
The Perth Mint has been operating for over a century but has only allowed full public access since 1990, following painstaking restoration of the classic colonial building. The hand-cut masonry facade had become soiled and disfigured by weathering, grime, algae and fungal growth. By the mid 1980s, the Perth Mint’s exterior had become ingrained with years of grime and dirt.
In 1987 the sandstone exterior was thoroughly renovated and cleaned, revealing the light yellow natural stone appearance that is visible today. To ensure that the appearance would be maintained the Mint decided to protect the freshly cleaned stone surfaces with a single flood-on application of the Driwal treatment.