joints are used where the slab needs to be able to move completely independently
of fixed elements within the floor space.
elements can be isolated in different ways depending on the anticipated
movement of the slab:
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.
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.