To limit the probability of inadequate rigidity of underlay panels, which could lead to the deformation or displacement of underlay at joints, which could lead to the cracking of ceramic tile.
Where finished flooring is required to provide water resistance, this is to limit the probability of the ingress of water into the underlay and the subfloor, which could lead to:
This is to limit the probability of negative effects on the air quality of indoor spaces, which could lead to harm to persons.