Masonry - Durability
Generally, concrete masonry is a durable and robust product that can be used for internal applications including the inner leaf of cavity walls. When used externally some protection may be required, depending on the exposure conditions and the type of block being used. The type of block suitable for use at or below dpc/ground level will depend on the block’s properties and if an aggressive chemical environment (sulfates or acids) is present. Tests have shown that a wide range of products can meet the necessary durability requirements.
Guidance on durability can be found in BS 5628-3 Code of practice for the use of masonry - materials and components, design and workmanship
For further information see the Concrete Block Association or the Autoclaved Aerated Concrete Products Association