Watertight Expansion Joints and Construction Sealants by EMSEAL

Compression Set

Compression set is the permanent loss of the ability to recover or self-expand that results after a material is subject to normal compression cycles.  Compression set is made worse by simultaneous exposure of certain materials to heat.

Impregnated, open-cell, foam is used as the backing for precompressed sealants because it features very low compression set.

Closed-cell foams suffer on average 25% permanent compression set under movement and temperature cycles typical in construction applications.

NOTE: The definitions of terms and terminology herein are rooted in the context of use in the field of construction-related joint sealing in EMSEAL’s experience. They are provided with the intent of offering a fuller understanding of the context of their usage. Any suggestions or questions regarding interpretation are welcome and should be directed to content@emseal.com. Thank you.