Why are expansion joints used in masonry?

Expansion joints are used in masonry primarily to allow for movement and minimize cracking. Masonry materials, such as brick and concrete, undergo thermal expansion and contraction due to changes in temperature and moisture content. Without the presence of expansion joints, these materials could buckle or crack as they expand or contract. The flexural capacity provided by the joints accommodates this movement, thus helping to maintain the integrity of the masonry structure over time. Consequently, proper incorporation of expansion joints is essential for long-term durability and performance, as they help preserve the aesthetic and functional qualities of the masonry.