A Shower Pan Liner For A Water Stopper
Here's here how I learned about a shower pan liner. I had this tile shower right next to our bedroom. I noticed what looked like a wet spot in front of the chest of drawers that was along the wall right behind the shower.
You can guess where the water came from.
Out of the shower the water came and soaked the oak flooring and slowly made it's way out all the way to the edge of the chest of drawers where I could then see it... What a mess...
Anyway, I wondered what happened to let that happen???
What you find out as you look at how to build a shower pan for tile is that shower floors just leak. The grout does not stop water and neither in some cases does the tile itself. Water just leaks through the floor.
In addtion at the walls to floor joint you can easily get cracks and that is another spot for leaks. Those joints are normally caulked in addition to the grout, but you know how caulk is. It will not last forever.
Another spot water gets past the surface is in the corners of the shower at the floor and all the way up the walls. Same story... Grout it there as is caulk but you still can get leaks.
So we had trouble in all those spots but in reality if the shower pan installation had worked as it, should the water would still have stayed in the shower and not in my oak floors.
Fixing those floors is another story.
The Shower Pan Liner Comes Out
It was clear that the pan had to come out. Shower floor options were few.
What it takes to get the base out is just simple beating out the masonry that makes up the base if it is put together the traditional way.
What was in that shower was a galvanized pan. The liner was torn up getting it out so it was impossible to tell where or how it was leaking.
What went back in was what is usually used now as a shower pan liner. It was a sheet of rubber-like vinyl, actually PVC. These are the standard liner membrane used now. There is another vinyl sheet type that gets used as it is more flexible and harddens slower. Those seem to rarely get used though as they are harder to find and cost more.
What happens in brief is the liner gets put in place between two layers of mortar as the shower pan is built up a layer at a time. A first mortar layer goes over the sub-floor and is sloped to the drain. that layer is there as a base for the liner sheet.
The liner is placed on the mortar after it has cured. It gets folded in the corners and stapled up high so no cuts or holes are low where you could get leaks.
At the curb there likely must be some cuts made to get sround and over the barrier but then those cuts must be sealed up wiht the right kind of adhesive.
The shower pan liner forms a pool that will catch all the water that makes it past the shower floor tile or in any cracks in mortar or other openings. Get it right and the shower will keep all the water right in the base or down the drain just as it should be. That's a good thing, since otherwise you have some serious trouble.