What is a brick movement joint?
What is an expansion joint in brickwork and blockwork? An expansion joint in brickwork and blockwork is a means of solving potential problems caused by movement. This movement could be a result of thermal expansion, moisture movement, creep and structural loading or the effect of chemical changes.
How often do you need a movement joint in brickwork?
In order to avoid the detrimental effects of differential vertical movement between the inner and outer leaves of a wall a horizontal movement joint should be provided at no more than every third storey or 9m, whichever is the less.
What is a movement joint in a wall?
A movement joint, also known as an expansion joint, is a dynamic component that is designed to relieve or absorb movement between structural elements and help prevent cracking.
Do brick walls need expansion joints?
3. Use expansion joints in your brickwork. Expansion joints separate brick masonry into seg- ments to prevent cracking caused by temperature change, moisture expansion, elastic deformation, settlement, or creep. They can be horizontal or vertical.
Where are movement joints required?
Movement joints should be provided in external walls at intervals of about 7.5m to 9.0m. The width of the joint should be between 10mm and 13mm. In internal walls, movement joints are only needed if the wall is going to be plastered before the brickwork has dried out.
Where are movement joints positioned?
Movement joint should be in full height masonry between window and door openings. Movement joint should not pass through openings due to the difficulty in continuing the joint between the frames and masonry and around the ends of the lintels.
What is the difference between expansion joint and movement joint?
In building materials, a control joint is used to control cracking while an expansion joint is designed to handle structural movement. By contrast, an expansion joint (or movement joint) is sized and formed at a width prescribed by the building design team and sealed and bridged later by an expansion joint system.
What width is a movement joint?
Movement joints in clay brickwork should be at least 18 mm and ties should be provided at 225 mm centres vertically alongside the joint.