Natural Hydraulic Lime (NHL) is a breathable, flexible and environmentally sympathetic binder.
When mixed with suitably blended aggregates it produces mortars, plasters and renders of varying strengths.
Natural Hydraulic Lime is produced by burning limestone that has clay mineral content resulting in the introduction of calcium silicate hydrates which give the binder higher strength than non-hydraulic lime.
Due to less energy usage than cement during manufacture and their reabsorption of CO2 when setting, NHL is an extremely environmentally friendly material.
NHL is suitable for use in new build, eco build and some building conservation projects.
Natural Hydraulic Lime binders come in three strengths, classified as NHL 2, NHL 3.5 and NHL 5. These are sometimes referred to as “feeble”, “moderate” and “eminent” respectively.
NHL 2 should be considered when pointing into soft brick and stonework or as a backing coat internal plaster.
NHL 3.5 is a good all-rounder and suitable for brick and stonework, renders and plasters.
NHL 5 should be used below ground (sub-DPC) and for extremely exposed buildings and \ or elevations. It is also used as part of a limecrete flooring system.
Roundtower NHL binders are available in 25kg bags and full pallets of 40 x 25kg bags.