HYDRAULIC LIME — is a type of lime derived from the baking and slaking of limestone and clay. It possesses hydraulic properties, meaning it can set and harden even when submerged in water. When combined with sand, hydraulic lime is utilised for plaster coats and interior foundations in construction.

It has been widely employed in traditional buildings, owing to its compatibility with older construction techniques and materials. The use of hydraulic lime allows for the creation of durable and breathable structures, providing an alternative to cement-based materials in heritage conservation and restoration projects.

Its versatility and compatibility with historic building methods make hydraulic lime a valuable component in the preservation of architectural heritage.