Limebaserade

Limebaserade materials refer to binders and coatings derived from lime that have been used for thousands of years in construction. They include lime putty and hydrated lime binders, as well as hydraulic lime products, which can contain clay or silica impurities that impart early strength and the ability to set in damp conditions. Common lime-based applications are mortars for masonry, plasters and renders for walls, limewash or lime-based paints, and limecrete for floors.

Chemistry and setting are central to lime-based systems. Most lime mortars and plasters set by carbonation, in which calcium hydroxide reacts with atmospheric carbon dioxide to form calcium carbonate. Hydraulic lime products also gain strength through hydration and pozzolanic reactions, allowing them to cure under moisture and at greater early ages. The result is a material that is typically breathable, retailing moisture away from the masonry rather than trapping it inside.

Properties and advantages of lime-based materials include their vapor permeability, elasticity, and compatibility with historic masonry. They accommodate minor substrate movements without cracking, help regulate indoor humidity, and generally have a lower embodied energy than cementitious systems. Lime-based finishes are favored in restoration projects and in new builds that aim for sustainability, durability in damp climates, and compatibility with traditional materials.

Limitations include slower strength development compared with Portland cement, sensitivity to improper moisture management, and the need for skilled workmanship. Compatibility is crucial: cementitious overlays or paints can trap moisture and damage lime substrates if not used carefully. Lime-based systems have a long history and continue to be used in conservation, heritage restoration, and eco-friendly construction.