Wonderboard Tile Backerboard should be fastened to a subfloor (exterior grade plywood) using 1-1/2-inch-long galvanized roofing nails having a head diameter of 0.40 inch and a nailing schedule of 6″ to 8″ O.C throughout the field. Nailing must be 1/2 to 2″ away from edges and corners. On floors use a latex modified morter setting bed notched with a 1/4 x 1/4 trowel. The Wonderboards should have a 1/8″ gap at all joints and corners. Fill the gap with morter but no tape is required.

The manufacturer does not recommend gluing or screws. I used to work for Louisiana Pacific who divested this product some years ago to Custom Building Products. Attachment specifications are from material data sheet I have from 4 years ago, and requirements may have changed.