see this link for one answer
http://www.oatey.com/shower_drains/lit/Shower%20Pan%20Liner.pdf
$6,800
The item used under the shower pan to create the slope for the drain is called a "shower pan liner" or "shower pan membrane". It is typically made of PVC or CPE (chlorinated polyethylene) and is installed over the subfloor and around the drain to create a waterproof barrier. The liner is then sloped towards the drain using a combination of techniques, such as sand or mortar beds, pre-sloped foam panels, or adjustable slope systems. The choice of method depends on the specific requirements of the installation and the installer's preference. Once the liner is in place and sloped properly, the shower pan can be installed on top of it, and the tile or other finish material can be applied. Proper installation of the shower pan liner is crucial for ensuring that water drains properly and does not seep into the subfloor or surrounding areas, causing damage or mold growth. HydroBlok systems are known for their durability, water resistance, and ease of installation. They can be used for both residential and commercial applications and are suitable for a variety of finishes, including tile, stone, and vinyl.
The center of the shower floor where the tile shower drain would normally be positioned ... drain base. After this step the sloped mortar bed should be ... pan liner or membrane in our instructions.
No, that is not common, but there are many different shower pans, so mistakes are possible.
How to Install Mortar Shower Pan Membrane LinerOnce you've framed the shower stall, it is time to install the pan liner and cement backer board to create a water tight seal.Remove the drain cap and tape over the drain to keep mortar and other debris from entering the drain. Put down a layer of felt paper to help prevent moisture from wicking down through to the subfloor. Place a layer of metal lathe over the felt paper. Trowel in a layer of mortar that it has a one quarter inch slope towards the drain. Once the mortar dries, place a layer of felt paper along the walls of the shower stall. Attach cement board with the rough side out along the top half of the walls. Install the shower stall membrane in the bottom of the shower so that it overlaps in the corners, covers the shower curb and is approximately six inches up the side of the walls. Cut out holes for the drain, the drain bolts and the weep holes. Seal the underside of the membrane near the drain with silicone. Nail the membrane that covers the curb only on the outside. Attach the remaining cement board leaving one inch clearance from the bottom. Caulk all seems. Place some pebbles near the weep holes to protect the openings. Trowel in a layer of mortar that has a one quarter inch slope towards the drain. Mortar the curb. Remove the tape from the drain.
a shower curtain goes on the outside and a shower liner goes on the inside so the shower curtain wont get wet
The best way is to install 6 mil or greater poly sheeting. this will ensure a longer lasting seal.
The shower may be leaking from: 1) A failure of the drain and associated piping itself (e.g., corrosion of the cast iron floor drain), 2) A failure of the shower pan, which is an ostensibly waterproof liner (may be metal or synthetic polymer) embedded in the tile floor (or comprising the plastic floor) which is mechanically connected to the drain; or 3) Leakage of water in the shower's surrounding area (walls, non-pan floor area, etc.) which is accumulating and dripping near the drain.
A shower curtain is for decor and hung on the outside of the bathtub/shower. Whereas a shower curtain liner is hung on the inside of the tub/shower to protect the shower curtain. In simpler terms...SHOWER CURTAIN: gets to hang and look pretty and be dry. SHOWER CURTAIN LINER: protects shower curtain from getting wet because it's the one getting wet!
Yes
Curtain in, liner out.
I can consider it to be both.