The foam spacer is mainly used in mirror mounting. It prevents deflection and stabilises the construction. It is used wherever there is a hollow space between the material and the substrate over large areas.
This absorbs the pressure that occurs during cleaning work, for example, and the mirror does not deform. This provides safety when handling the fragile material. If the mirror is fixed with self-adhesive mirror sheets, bending would cause the adhesive tape to peel. This is unfavourable and can damage the adhesive bond in the long term. Spacers contribute to the longevity of the connection.