Movement Joints - Location

BS 5385-1:2009 deals with the design and installation of ceramic, natural stone and mosaic wall tiling in normal internal conditions. Section 6.5 deals with movement joints.

Section 6.5.1 recommends the necessity to consider movement joints at the design stage of a project for reasons such as background movement due to such factors as drying shrinkage and moisture and thermal changes.

Section 6.5.2 further identifies appropriate locations such as where tiling abuts other materials and where stresses are likely to be concentrated, for example at changes of alignment.

BS 5385-3:2007 Wall and floor tiling part 3 deals with the design and installation of internal and external ceramic and mosaic floor tiling in normal conditions.

Section 6.8 deals with movement joints and recommends that flexible joints should be used at floor perimeters.

BS 5385-4:2009 deals with the design and installation of ceramic and mosaic tiling in special conditions. Section 7 deals with wet and damp conditions.

Section 7.2.4 deals with installations not immersed but subject to frequent contact with water such as showers and recommends special attention should be paid to sealing the gaps between wall and base, particularly if the installation is on a suspended floor and that movement joints should be sealed with curing sealants.

• The NHBC requires the design to consider and make provisions for interface joints between 2 different materials/substrates. If the interface will have movement then the provision of the joint should accommodate the expected actions and suitable materials used.

Comment: It is clear from the stated Codes of Practice that a joint between two surfaces subject to differential stresses should be treated as a movement joint and provided with a flexible joint seal such as a curing sealant.