Waterproofing, what lies beneath is the reason for a leak free shower. There are many different options for waterproofing a tile shower, roll on membrane, the traditional PVC liner, many fabric membranes and we have the OneLiner these are all waterproofing. Some more work then others but following manufacture installation will make a leak proof pan.
Any time you are building a shower pan or installing our OneLiner you need to do a water test, in our installation of the OneLiner this is after the pan and curb are in plug the drain, put water mark level and wait 24 hrs to make sure there are no leaks.
Always check building code in your area for any plumbing part of your do it yourself shower installation, in some areas you may need a licensed plumber to install the drain flange to the pipe in sub floor.
Pre Pitch is the minimal mortar base under the liner to ensure that secondary water flows to the drain, starts the pan to slop to the drain also acts as some reinforcement to sub floor. If you are on a wooden sub floor most likely need to use lath reinforcement and tar paper keep moisture from mortar from getting into wood floor. Pre Pitch sticks still in mortar bed.
Our OneLiner is a structured waterproof shower pan liner, it is designed to have a pre slope under the liner so you may see waves in the bottom of the OneLiner. With the mortar base in place and Quick Pitch system this will sufficiently reinforce cement, reducing the flexibility in the bottom of the OneLiner.