When designing for brickwork movement consideration must be given to the geometry of the building and its orientation.
South, South West and South East facing elevations will be susceptible to more movement and an increase in joint frequency
should be considered, particularly where darker coloured bricks are being used.
Unrestrained or lightly restrained unreinforced walls expand approximately 1mm/m during the life of a building due to
combined thermal and moisture movement changes. Not all clay types expand at the same rate and in some cases an
allowance of greater than 1mm/m may be necessary. It is advisable to check this information with the brick manufacturer
when specifying movement joints.

As a general guide and to allow for the compressibility of the movement joint filler, the width of the joint in millimetres
should be about 30% more than the distance between joints in metres. For example, movement joints at 12m centres should
be 16mm wide.
A vertical movement joint should be located at no greater than half the maximum spacing from a corner or return in a wall.
Hence for joint spacing of 12m in a straight run of walling, a joint is required to be no more than 6m from the corner.

Vertical Movement Joint Spacing
In freestanding walls, parapet walls, unrestrained or lightly restrained brickwork and non-load-bearing cladding or
spandrel brickwork panels brickwork movement joints should be provided at twice the frequency recommended for full
walls as described previously. For these walls, the joint spacing should not exceed 6m.
Note:- Some manufacturers recommend reduced joint spacing for copings and cappings.

Movement Joint Positions and Building Details

Features of the building which should be considered when determining joint positions in masonry are:-
1. Short returns in clay masonry
2. Changes in height or external materials
3. Window and door openings
4. Location of wall ties with respect to movement joints 5. Bed joint reinforcement
1. Short returns in clay masonry
If a return in the length of brickwork is less than 675mm, movement joints should be included to avoid the risk of cracking.

2. Changes in height or external materials
It is advisable to consider locating vertical expansion joints where there is a significant change in height within the building
elevation or wherever there is a change in material such as rendered blockwork or stone. This can be achieved by the
introduction of a vertical, compressible joint or a “slide-by”.

3. Window and Door Openings.
Movement Joint Positions and Building Details

4. Changes in height or external materials
It is advisable to consider locating vertical expansion joints where there is a significant change in height within the building
elevation or wherever there is a change in material such as rendered blockwork or stone. This can be achieved by the
introduction of a vertical, compressible joint or a “slide-by” detail.

5. Bed Joint Reinforcement
Bed joint reinforcement may be used to extend the centres of vertical movement joints and to minimise the risk of cracking.
Areas above doors and above or below windows may benefit from the inclusion of bed joint reinforcement to distribute
tensile stresses and avoid localised cracking. Proprietary bed joint reinforcements with parallel bars of at least 3mm
diameter can be used to increase joint spacing. Light “chicken wire” meshes can be used for crack control only.
Brickwork, like concrete, is good in compression but
poor in tension and the addition of reinforcement to the
mortar bed joints will:
J Give more freedom in the spacing of movement joints
J Reduce cracking due to the following causes:
– Movement due to fluctuating temperatures
– Flexural or tensile stresses resulting from loading
– Stress concentrations around openings (windows
and doors)
– Differential movement between bonded materials
– Differential settlement
– Irregular elevations
– Changes in wall thickness
Reinforcement is supplied in various widths and shapes
to suit the application, but for external walling suitable
grades of austenitic stainless steel should always be
specified.
Design guides and technical and structural advice are
available from manufacturers and suppliers, together
with guidance on the correct application and installation
of the material.

Compressible joint filler
Horizontal Joints to Accommodate
Vertical Movement
Materials for Movement Joints
Present evidence suggests that vertical movement of unrestrained walls is of the same order as horizontal movement.
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. For buildings
not exceeding 4 storeys or 12m height, whichever is the lesser, the outer leaf may be uninterrupted for its full height.
The material for filling movement joints to accommodate expansion should be easily compressible to approximately 50% of
its original thickness. Flexible cellular polyurethane, cellular polyethylene or foam rubbers are satisfactory materials.
Movement joints should be sealed with polysulfide or low modulus silicon which has sufficient flexibility to accommodate
movement and be resistant to water penetration.