What is Moisture Movement in Building?

Materials used in building construction have pores, especially manufactured materials like cement or lime concrete, mortar, some types of stones, timbers, and bricks from clays. Such porous materials inherently absorb moisture from many sources and expend which is followed by shrinkage on drying. These moisture movements are of two types

• Reversible movements

• Irreversible movements

The reversible movements are those which have reverse movement on absorbing moisture and subsequent drying. Such movement is of cyclic nature which is due to change in inter-pore pressure controlled by moisture change. The degree of movement depends on porosity and molecular structure of a material.