How should movement be accommodated within the structure?
The provisions of the Eurocode for masonry are written as a principle followed by a series of application rules to achieve the principle. In the case of movement, the principle is:
“The possibility of masonry movement shall be allowed for in the design such that the performance of the masonry in use is not adversely affected by such movement.”
The way of achieving this situation is by the use of movement joints to subdivide large areas of brickwork into smaller panels such that in particular shrinkage of the brickwork does not allow sufficient tension to build up in the wall that it cracks. In particular, long low panels are to be avoided. The maximum spacing of movement joints is a national matter and the National Annex to BS EN 1996-2 recommends a value of 9m for concrete brickwork with the provision that it may be less if the length: height of the sub-panel created exceeds 3:1. In practice, movement joints are often spaced at 6m – 9m as recommended in PD6697. Tobermore recommend a maximum spacing of 6m.
Refer: See Tobermore Walling and Masonry Brochure “Design for Movement”