There are three ways to install a skirted bathtub, which is a tub that has one flat, finished side that faces the room and three sides that fit next to walls. The installation process will depend on whether the skirted bathtub has legs. The skirt on a skirted bathtub, with or without legs, is not designed to hold the weight of the bathtub. Be careful not to drop the bathtub on the skirt or set it down where the weight of the tub will rest on the skirt.
Bathtub Without Legs
Use a hammer or drill with a screwdriver bit to remove the drywall from the wall studs where the skirted bathtub will be installed. Sweep up the debris. Set the bathtub in place and check it with a level along the top edge of the sides and both ends to make sure it is perfectly level. Use a tape measure to make sure there is a one-eighth-inch gap between the floor and the skirt.
Use a pencil to draw a circle on the subfloor where the drain will be installed. Remove the bathtub. Install the bathtub drain. Spread smooth mortar on the subfloor to level and raise it, if necessary, so that the bathtub is level and the skirt is above the floor.
Set the skirted bathtub in place. Use the level to make sure it is sitting level. Wedge small shims in place between the wall studs and the edge of the bathtub if it is not snug against the studs. Use screws and a drill with a screwdriver bit to attach the bathtub to the studs if it has pre-drilled holes along the top lip of the flange.
Install the drain connection through the drain hole of the skirted bathtub. Place plumber's putty around the bottom of the drain cover. Put the drain cover in place and tighten it down. Connect the drain stopper/overflow fixture. Adjust the linkage between the drain stopper and drain control lever until it closes properly.
Put a waterproof wall covering around the skirted bathtub. Run a bead of silicone caulk between the top edge of the bathtub and the bottom of the wall covering and on the floor along the bottom of the skirt.
Bathtub With Legs in Epoxy Cement
Set the skirted bathtub in place. Adjust the legs as necessary until the bathtub is perfectly level. Check the top edges of the bathtub with a level. Make sure the skirt is one-eighth-inch above the floor. Use a pencil to draw an outline around each leg after determining exactly where the bathtub will be placed.
Remove the bathtub and lay it on its side on a thick, non-abrasive pad. Spread a thick coating of two-part epoxy cement on the bottom of each leg.
Pick the skirted bathtub up with one person at each end. Turn it upright, being careful not to touch the floor or padding with the epoxy cement-coated legs. Set the bathtub in place with each leg lined up in its predetermined location. Press down on the bathtub as it is set into place to form a tight seal between the legs and floor. Connect the drain and overflow as in Section 1. Run a bead of silicone caulk on the floor along the bottom of the skirt.
Bathtub With Legs in Mortar
Follow the procedure outlined in Section 2 to level the skirted bathtub and determine its position. Mark the leg locations on the floor.
Cut 1-by-2 boards into 16 4- to 6-inch-long sections. Screw or nail four sections of wood in a square around each leg outline to form a mortar mold. Pour the mortar into each mold to a depth of 1 1/2 inches.
Pick up the skirted bathtub with one person at each end and carefully set it in place. Make sure each leg is centered in mortar and press the bathtub down into place. Connect the drain and overflow as in Section 1. Use silicone caulk to seal the gap between the skirt and floor.