Horizontal expansion joints should not be spaced further apart than:

Horizontal expansion joints are critical in construction for managing the movement that occurs due to temperature changes, moisture variations, and general building settling. Proper spacing of these joints helps to accommodate the expansion and contraction of materials, which can otherwise lead to structural issues such as cracking or warping.

The recommended maximum spacing of horizontal expansion joints is 20 feet. This spacing is based on industry practices that ensure adequate flexibility and movement allowance for most building materials, especially those used in glazing applications. By limiting the distance between joints to 20 feet, the construction maintains an effective control over the thermal expansion that may occur, allowing for more manageable movement without compromising the structural integrity or aesthetic quality of the building.

If the spacing were to exceed this distance, the potential for damage increases significantly, as larger spans cannot accommodate the same level of movement. Therefore, adhering to the 20-foot maximum helps ensure long-term performance and safety in construction projects involving glazing and related materials.