is formed from a single sheet of material backing member 22 includes an insulate base 34 and generally parallel holding guides 36 which extend outwardly from and are integral to the insulate base 34 the holding guides 36 are spaced to define channels 38 one side 39 of the holding guide 36 is angled to form a knife edge 40 which extends into adjacent channel 38 knife edge 40 retains thin brick tiles 26 within channel 38 and also allows accommodation of tolerances in the size of thin brick tiles 26 another side 41 of the holding guide 36 is generally perpendicular to the insulate base 34 a generally vertical groove 43 is formed in backing member 22 to allow water to drain the groove 43 is preferably on 16 inch centers and has a depth of 1 8 inch into the channel 38 as should be understood the groove 43 extends through sides 39 and 41 as well as into backing member 22 1 8 inch the channels 38 of the backing member 22 are formed by cutting directly into an original sheet of insulation material the knife edge 40 in particular is formed by cutting side 39 of the holding guide 36 at an angle inwardly from a top portion of the holding guide 36 side 39 having the knife edge 40 forms an acute angle with the channel 38 this design permits knife edge 40 to have line contact with a shin brick tile 26 in order to provide sufficient resistance.