Applied stone wall cladding

Stone has always been synonymous with solidity, durability and even luxury and wealth. The high cost of this material, mainly due to the difficulty of extracting, transporting and cutting it, has gradually led to a reduction in its use in the form of solid stone (ashlar), in favor of thinner products (generally 5 to 50 mm) marketed in the form of slabs whose surface area is generally less than one square meter.

At these thicknesses (under 8 cm), they cannot be self-supporting, so they need to be fixed to a stable support. To achieve this, special fastening systems had to be developed, adapted to the supports, i.e. the low-cost materials most commonly used in contemporary construction: brick, breeze-block or concrete.

The improved durability and aesthetic appeal of this natural material are also appreciated, while it also offers a cost-effective solution to the problem of thermal insulation from the outside.

With this technique, the use of stone in the skin of buildings is not specific to any one region; it's a very old process that has since been perfected and generalized in all industrialized countries.

Natural stone is an inherently ecological material. Its processing requires little energy and has little impact on the environment. The location of quarries means that transport distances are kept to a minimum, thus reducing the ecological footprint. Natural stone can be reused almost indefinitely.

It also has scientifically proven ecological qualities:

• it does not emit toxic fumes into the air, guaranteeing healthy air. Stone used indoors can earn the A+ label for indoor air quality;

• its thermal inertia provides the natural thermal regulation increasingly appreciated by architects and designers.

In the early 1970s, rules were laid down for the installation of thin stone facade cladding, which have been progressively improved and supplemented to date. In terms of regulations, DTU 55-2 "Revêtements muraux attachés en pierre mince" has been the benchmark since December 1979, while standard NF P 65-202 has made a number of improvements.

To understand all these relatively new installation techniques and the associated pathologies, it's important to bear in mind that stone only plays a decorative role: it is in no way a water- or airtight wall.

However, as this is "heavy" cladding, it is common practice to require the same ten-year warranty for such work as applies to the shell. It will be interesting to follow developments in case law on this subject.

Finally, let's not forget that stone is a natural material...