Basix Ultra Silver Underlay UL12 is a high-density recycled rubber underlay with an aluminium vapour barrier, ideal for all laminate floors and Basix engineered floors. This high-density recycled rubber underlay improves walking comfort and reduces footfall sound. It can be used on all sub-floors and is really easy to lay - just roll it out across the room making sure the edges butt up tight to each other, and then lay your new floor on top.