Simple Guidance about Expansion Joint Movement Rating

Movement rating attempts to categorize the anticipated range of horizontal change in a joint opening.


For example, a 4” (100mm) nominal joint, which is expected to have a range of horizontal movement of plus 2” (50mm) or minus 2” (50mm), would be denoted as +- 50%.


Joints designed for thermal movement will typically have a movement rating in the +-10% to -+25% range.




Joints designed for seismic movement will typically have a rating of +- 50%. Wind load movement is also rated as seismic.


As a general rule, expansion joints can be divided into three categories based on their total range of motion:

Small Movement Joints: Total movement range < 1 ¾ in

Medium Movement Joints: 1 ¾ in < Total movement range < 5 inch

Large Movement Joints: Total movement range > 5 inch


To learn more about Prospec Specialties expansion joint range and their movement rating, email info@prospecspecialties.com