Isolation Joints

Summary

Isolation Joints - are designed to minimise restraint on a slab from fixed elements such as columns, walls, bases or pits.

Technical Information

Isolation joints are used where the slab needs to be able to move completely independently of fixed elements within the floor space.

Different elements can be isolated in different ways depending on the anticipated movement of the slab:

At the perimeter of the slab, it is normally sufficient to turn the slip membrane up so that it forms a barrier between the edge of the slab and the fixed element. This is because the slab will only move away from the element so it is only necessary to ensure that they are not bonded together.
To isolate fixed elements set within the slab, it is necessary to provide isolation detail which allows movement towards the element as well as away from it. This is achieved by setting a strip of highly compressible material (usually foam) within the isolation joint.

Isolation joints do not provide any load transfer or connection to any other element. Therefore, issues such as curling and possible trafficking need to be considered.