A product better suited for the task is duct-sealing mastic, available in tubs at heating supply houses, hardware stores, and home centers. To apply duct mastic, dip a gloved hand into the tub, scoop out some mastic, and smear it all around every single joint you can find in your ductw...
Apply the tiles using mortar and spacers the same way that you put them on the wall. 7 Cut tiles to fit in the corners and edges. As you get close to the edge of your shower wall, you’ll probably find that at least 1 of the tiles doesn’t fit neatly into the space left. ...
Use an industrial-strength glue to secure the tile to the backing. Flip the tile so it’s facedown, but leave the backing face up. The glue comes in a squeeze bottle, so it’s easy to apply in neat lines. Start with the backing, spreading a line about 1 in (2.5 cm) from its ...