In many circumstances movement joints are overlooked, however, a lack of movement joints can be a contributing factor to many different types of failure. Furthermore, if you do not include movement joints in the specification liability for any resulting problems could fall to the architect, even if the problem doesn’t directly relate to a lack of movement joints, as it’s the architect’s responsibility to specify the type of joint and location of them.
The question, however, is how do you provide the movement joints necessary to ensure a durable installation and what movement joints should you use?
Movement joints need to go through the tile and screed covering and therefore need to be designed at specification. Understanding the types of movement that can occur, namely drying shrinkage, differential movement, deflection movement, structural movement, moisture movement and thermal movement, will help when deciding which type of movement joint will best counteract the resulting stresses.
In floors there are two basic types of movement joints, structural and non-structural. Both types will be subject to different movement patterns, for example, whether movement will occur from the tiled covering through to the floor slab or just in the tile and screed covering, and this will affect the type of joint needed to prevent damage.
Pre-formed joints can accommodate roughly 15-20% of their movement zone. The Schlüter®-DILEX range of movement joints offer complete protection and are available to specifiers in a wide selection of materials, colours, and movement capability.