Movement or Construction Joints ~ provide an alternative to ties
or mesh reinforcement in masonry bed joints. Even with
reinforcement, lightweight concrete block walls are renowned for
producing unsightly and possibly unstable shrinkage cracks.
Galvanised or stainless steel formers and ties are built in at a
maximum of 6 m horizontal spacing and within 3 m of corners to
accommodate initial drying, shrinkage movement and structural
settlement. One side of the former is fitted with profiled or
perforated ties to bond into bed joints and the other has plastic
sleeved ties. The sleeved tie maintains continuity, but restricts
bonding to allow for controlled movement.Note: Movement joints in clay brickwork should be provided at 12 m
maximum spacing and 7.5 to 9 m for calcium silicate.
Ref. BS 5628-3: Code of practice for use of masonry. Materials and
components, design and workmanship.Construction Joints