Increasing attention is being focused on the durability of the materials forming cladding assemblies.

This attention is a direct result of the very high costs now associated with the repair and maintenance of our portfolio of ageing buildings and by the widely differing philosophies applied by architects, building scientists and builders to design, construction and restoration work in terms of materials, procedures and assumed life expectancies.

Localized deterioration of masonry in the form of delamination and crumbling of the masonry units themselves is a common occurrence with failure happening either randomly or at specific repetitive locations.

The relationship between masonry deterioration and both cold weather air exfiltration and the presence on the face of the masonry of melt water from perched accumulations of snow and ice will be examined.

The applicability of today’s testing methods as referenced in the CSA and ASTM standards will be reviewed and the merits of the procedures now widely used in Europe will be briefly discussed in relation to temperature gradient conditions typically existing in a masonry wall.

The different categories of masonry deterioration will be briefly discussed together with repair options.