I bought a 30 from lowes and decided to build a hearth instead of buying a prefabbed pad. so I started out cutting back old carpet and pouring self leveling concrete pad to build off of. then did a frame out of steel studs 1 inch fibrefrax blanket (its dirty cause I work in a foundry where it often gets used once to cure refractory in a box or bowl and thrown out. so it was free to me). then some flashing to encapsulate it. 2 layers of durrock and tile.