Veneer underlayment

An underlayment for use between a veneer material and a foundation surface. The underlayment includes a base layer and a series of individual supports extending upwardly from the base layer and being configured to create voids in a layer of bonding material used to adhere the veneer material to the underlayment. Each of the individual supports includes at least one outer wall extending upwardly from the base layer， the outer wall extending at least partially around a perimeter of each of the supports. An internal wall is spaced from the outer wall and extends downwardly toward the base layer. A protrusion forms an overhang beneath which a heating element can be fitted. A liner material is bonded to an undersurface of the base layer and extends beneath the internal wall. A space is defined between the at least one outer wall， the internal wall and the liner material.