Traditional brick or masonry structures on heavy clay soils are often damaged by the clay shrinking due to loss of moisture caused by the transpiration of grasses, plants and trees. The problem is most acute in the south east of England where these clays predominate and where the rainfall is lowest.

The long drought of the summer of 1976 caused extensive drying and damage to buildings not previously affected; trouble was reported in buildings as far north as Yorkshire where high rainfall normally prevents the clay drying.

2 pages. (Revised edition - 1977)