Lime Binders

Lime Putty

Slaked Lime Putty

Lime putty suitable for building can only be made by slaking which must start by reacting soft-burnt high calcium quicklime (not hydrated lime) with an excess amount of water. Our lime putty is slaked from fresh soft-burnt high calcium quicklime , screened and then aged for a minimum of three months. This produces a product that is suitable for brick and stone mortar as well as fine plaster work. Three years of slaked lime putty aging takes place to produce finer lime putty with better coverage and performance for our Old World European Limewash. Slaked Lime Putty for Frescoes is aged for ten years. The aging process ensures that the lime particles are extremely fine, making this product the ideal choice for conservation work on frescoes. Made from non-hydraulic high calcium limestone with a 98% purity rating.

Our slaked lime putty products meet and/or exceeds ASTM C1489 – Standard Specification for Lime Putty for Structural Purposes.

Heritage Pure Lime Putty ingredients also meet or exceed ASTM C5 – Standard Specification for Quicklime for Structural Purposes.

Beware of “lime putty” products that do not meet ASTM C5 as they are most likely made from dry hydrated lime meaning they can be soaked but cannot be slaked. Dry hydrated lime is a plasticizer not a binder. No length of time soaking dry hydrated lime in water will ever produce an appropriate binder.

Natural Hydraulic Lime

Natural hydraulic lime is a traditional building material that was widely used in Europe prior to the development of portland cement. Moderately hydraulic lime (NHL 3.5) is recommended for most historic structures that are exposed to extreme conditions and/or high moisture levels. All-natural, flexible and permeable, natural hydraulic lime is an excellent choice for strawbale construction and sustainable new design projects.

Natural Cement

Natural Cement was sometimes used for masonry construction in the United States, primarily during the 19th century. Natural Cement plants were established in regional construction hubs during the 1800s but all were quickly shut down as portland cement manufacturing took over the market for hydraulic masonry cements due to lower cost, faster set and stronger, more predictable performance. Natural Hydraulic Lime is a suitable replacement for historic natural cement binders due to its similar chemistry, greater permeability, slightly softer compressive strength and predictable performance.