Established in 1851, the St. Astier quarries are today the largest producer of natural hydraulic lime (NHL) in France. The St. Astier products are pure. No additives, such as air entrainers, water repellants or others, are used. They are produced under a strict and controlled automated process which will not allow substandard material to go through. NHL means just that: natural hydraulic lime with no additions. The assurance on the pureness of the products starts from vast rock deposits uniquely composed of limestone with uniform and constant silica layers or clusters. Controlled burning (max 1000°C) - with continuous CO2 checks to regulate automated slaking and expansion tests - where substandard material is rejected, ensures constant high quality.

The absence of soluble salts (only traces of SO3 are found, no other) and the high amount of available lime are two of the main characteristics of the products. NHL mortars are known to have low shrinking values and high resistance to frost. They are quite workable and allow the highest reproduction of the sand colour. Their vapour exchange properties are remarkable, ensuring that the applcation areas will breathe, thus avoiding the formation of condensation. The availability of various strengths in the range makes the work of the restorer easier.

There is very little need to blend or gauge when you can choose between eminently, moderately and feebly hydraulic products, all bearing the production guarantee of St. Astier. Another characteristic of all St. Astier NHL products is their low density, with resulting economies for the user. On a 1:2 volumes mix, for example, one would need only 305kg of NHL 3.5 versus 675kg of lime putty or 725kg of cement. St. Astier NHL products have been used for some of the most important restoration and conservation work in France, such as Amiens, Reims and Perigueux Cathedrals, the Louvre Museum and

innumerable other vernacular and secular buildings.

In the UK, the products are being increasingly used in important sites with extremely good results. The St. Astier NHL range is available in the UK only through a network of specialised companies, themselves involved for many years in the complex task of adopting the right product to ensure the most reliable results.

Available from:
The Lime Centre Morestead
Winchester
Hants. SO21 1 LZ
Tel: 01962 713636