Building Expansion Joints

An expansion joint (or movement) joint is an assembly designed to hold parts together while 

safely absorbing temperature-induced expansion and contraction of building materials, and 

vibration, or to allow movement due to ground settlement or seismic activity. They are 

commonly found between sections of buildings, bridges, sidewalks, railway tracks, piping 

systems, ships, and other structures.

Building faces, concrete slabs, and pipelines expand and contract due to warming and cooling 

from seasonal variation, or due to other heat sources. Before expansion joint gaps were built 

into these structures, they would crack under the stress induced.