The use of natural stone materials in construction is now experiencing a marked revival particularly for external claddings. In contrast with most other construction materials, there are few British Standard tests for natural stone or Standard specifications defining the minimum quality requirements for various purposes. The Code of Practice for cladding is inadequate in these respects.
The range of test methods provided by ASTM and the complementary series of Standard specifications covering the major stone families are summarized but none of these directly address durability. Selected quality assessment procedures from German, Italian and other European practices and a number of different approaches to the evaluation of durability of stone are critically reviewed. The crucial importance of representative samples in such evaluations is recognized but the aspects of source selection and sampling are not discussed in detail.