The Natural Building Centre

Y Ganolfan Adeiladu Naturiol.

Natural Hydraulic Lime

See our ranges & prices

This is a dry powdered lime produced from limestone containing clay and other impurities, which enable it to set without exposure to air. It is therefore used for providing a faster initial set in more extreme conditions including under water.

Singleton Birch (Secil)

The Singleton Birch product range now compromises:

  • NHL3.5 – this product contains up to 18% clay content which gives a slightly faster set (15-20 days in water).
  • NHL5 – has up to 25% clay content which means that a much faster set is achieved(hours/days).

These limes have become increasing popular over the last decade because of their comparative ease of use and strength compared to fat limes, but they should be used for the right situation as limes that are too strong can cause damage to the fabric of the building in the same way that cement does. The golden rule is that the mortar or plaster should always be weaker than the building components it is used on.  Call for advice or see Documentation below. The NHL3.5 and NHL5 products in this range are produced in Portugal by Secil who have been producing high quality limes for over 100 years.

St Astier Natural Hydraulic Limes (NHL)

St Astier Natural Hydraulic Limes (NHL) and derivative products have been produced by the same families since 1851. The mineralogical characteristics of the raw materials, the manufacturing process and the quality controls are such that users are assured of the constant performance of the products. The experience acquired over the years is shared with the user through the assistance available from the Technical Department and from carefully chosen specialist distributors, able to assess the type of lime mortar, plaster or render required. This is especially important in Conservation and Restoration, where mortars should be project specific in order to ensure their compatibility with existing materials and the fabric of the buildings. In new build St.Astier Limes have developed a range of binders and ready mixed mortars combining all the characteristics required by today’s builder in terms of speed of setting, strength, elasticity, plasticity, low capillarity and shrinkage, with the breathability and aesthetic quality of lime mortars. The result is that these lime mortars are becoming the obvious alternative to cement mortars also in the new build and eco build sectors. The ecological benefits of lime mortars such as CO2 re-absorption and condensation control provide vital answers to some of today’s environmental and energy saving requirements which cannot be ignored by the professions and trades involved in the protection of the built heritage and in the construction of our new living environment.

St. Astier natural hydraulic limes (NHL) and lime mortars have been adopted in a number of countries and in the most diverse climatic conditions, from the Arctic circle to the desert, from marine locations to high mountain sites. They have been and are used on some of the most important world heritage sites, in vernacular and ordinary buildings, in reproducing the characteristics of ancient mortars as well as providing solutions to modern architectural mortar requirements. The technical expertise at hand will also assist in achieving engineering solutions when an alternative to cement mortars is required.


Product Documentation

Natural Hydraulic Lime Range

Product Range Quantities Price exc. VAT
St Astier NHL2 Hydraulic Lime 25Kg bag (40 bags per pallet) £14.50
St.Astier NHL3.5 Hydraulic Lime 25kg bags (50 bags per pallet) £13.50
St.Astier NHL5 Hydraulic Lime 30kg bags (40 bags per pallet) £14.00
Hydraulic Lime Singleton Birch (Secil) NHL2 25kg bags (40 bags per pallet) £13.00
Hydraulic Lime Singleton Birch (Secil) NHL5 25kg bags (40 bags per pallet) £11.50
Hydraulic Lime Singleton Birch (Secil) NHL3.5 25kg bags (40 bags per pallet) £12.00


We are open for sales and collections Monday to Friday between 8.00 and 5.00 and on Saturday mornings by appointment – and its always a good idea to ring first and check stock before you visit. We can also arrange delivery to anywhere in the UK, just ring or email us for a quote.