Expansion Joints

Providing horizontal and vertical expansion joints in walls helps to reduce the cracks to a considerable extent. Horizontal and vertical expansion joints absorb vertical and horizontal movement respectively. In general, expansion joints have to be provided for every 15 m. The sealant used for joints are natural or cellular rubber, bitumen, expanded plastics, coconut pith, etc. The depth of sealant should not be more than half the width of joint and should not be less than 4 mm. Figure 17.17 shows some typical locations for joints.

Figure 17.17 Plan of locations of expansion joint

Typical expansion joints in brick masonry provided at different locations to avoid cracks are shown in Fig. 17.18 to 17.20.