This product is a traditional material made from 100% all-natural ingredients, and it is breathable and flexible. Hydraulic lime is distinguished from non-hydraulic lime by its ability to cure in damp/wet conditions. It is suitable for historic masonry that may be exposed to high moisture levels or extreme conditions, and it is also recommended for sustainable new-build projects and strawbale construction that relies on breathable, all-natural construction materials. Heritage Natural Hydraulic Lime Stucco/Plaster is a dry material with aggregate pre blended into the product. The product is applied in three coats: a scratch coat, a brown coat and a skim coat. This product is ready to use; just add water and mix at the site before applying the stucco. Weight: 40 lbs