Dave Gobis is a third-generation tile setter, retired tile consultant, and former executive director of the Ceramic Tile Education Foundation.
Using a semi-vitreous or vitreous tile over regular dry-set mortar is a better approach than trying to surface-seal the slab.
Q. Any suggestions on the best way to insulate the ceiling of a garage? The garage will have an in-law suite above, with living, sleeping, and bath areas. The floor construction will be 2x10 joists, or possibly 117/16-inch wood I-joists. I'm especially co