To install a shower pan liner, place the liner at the shower floor's bottom, lap its sides several inches up the shower's walls, and secure it to the wall studs using nails. Start installing the liner at the floor's center, make it fold over the curb of the shower, and secure it tightly at the shower's corners.
After placing a shower pan liner at the shower floor's bottom, make a hole at its center above the drain hole area using a utility knife. Position a drain base on the cut area, and tape duct tape over it. This ensures that debris does not accumulate in the drain.
Then, lap the shower pan liner's sides approximately 10 inches up the shower's three walls. To affix the liner to the wall studs, use 8-penny nails, and position them 1/2 inch from the liner's top edge. Drive the nails into the wall studs, rather than only the drywalls.
After placing the liner at the shower floor's center, extend it in an outward direction till the walls, while ensuring that the liner's bottom rests flat on the shower floor. At the corners, ensure that the liner overlaps tightly while remaining flat.
Fold the shower pan liner over the curb of the shower, as it is not possible to drive nails in this region. Affix the liner to the curb's outer top edge using nails. After installing, check if the liner rests flush with the shower's perimeter.