Tile Underlayment

Yesterday and today we've spent some time installing a layer of sound isolation barrier, which goes on top of the subfloor and beneath the finished floor. Since we have living space in the basement, we're hoping to keep noise isolated in each space. In the ceilings on the first floor we used spray foam insulation to keep noise from going through the ceiling into the upstairs bedroom. Given the foot traffic we'll have on the first floor, we are adding the additional layers of underfloor material.

For tile we're using a 3 mm thick styrofoam-like composite material with an adhesive backing, made by Sound Isolation Company. Our good friend Rude (of Portland Cement Co. and who's laying our tile and pouring our countertops) tells us that this stuff is great to work on and that it takes thin set (the mortar mix used to hold tile in place) as well as Wonderboard does.