Hang cement backer board. Measure the space for the tub surround and cut out the measurements from sheets of cement backer board. Screw the backer board directly to the wall studs with exterior grade screws.
Patch any seams in the cement backer board. Fill the seam with a thin layer of thin-set mortar. Place fiberglass mesh tape over the mortar and then cover it with another layer of mortar. Let the mortar dry overnight.
Determine the layout for the tile. Whirlpool tubs can be any size, so the tub surround may not look like a typical tub surround. Decide on a layout for the tile and mark layout lines on the cement backer board with a pencil.
Apply thin-set mortar to the backer board walls with a notched trowel. Begin spreading the mortar at the bottom of the wall, directly above the tub. Press the tiles into the mortar and work your way up the wall. Place tile spacers between the tiles to keep them from slipping down the wall before they dry. Make necessary cuts to the tiles with a tile saw. Cut out the holes for the tub and shower supply pipes with a diamond-grit hole saw fitted on an electric drill. Let the mortar dry for 24 hours.
Apply grout to the tile surround. Spread the grout over the tiles with a rubber trowel. Let the grout cure for twenty minutes and then wipe away the excess grout with a damp grout sponge. Allow the grout to dry overnight.
Buff the top of the tiles with a dry cloth. This will remove the haze from the top of the tiles.
Caulk the space between the tub surround and the tiles with caulk. Spread a bead of caulk along the gap. Smooth the caulk with your finger. Allow the caulk to dry per manufacturer directions before use.