This is a pretty simple discussion because I know how to do the best of both worlds like many other qualified tile contractors. The problem occurs when a contractor has no idea how to do a mud floor… and watched an idiot proof video on youtube about how to install a Schluter Kerdi pan or something of the likes. I honestly do not believe that one way or the other is necessarily quicker or cheaper to do for various reasons.
A preformed shower pan (or tile ready pan) is obviously advertised as quicker installation and generally it is. Just mortar down and go right?!? Not always… with a tile ready pan you are always confined to the drain location provided in the pan so plumbing work can take longer to move into position. If joists are in the way, that can cause a huge problem because you just can’t go chopping through them to get a pipe through.
Here are some other things that can be limiting with preformed shower pans:
- Drain grate selections for the homeowner
- Process of installation (sometimes you have to do the pan after tile walls are installed so your not denting the foam etc…)
- Piecing together a pan when it’s too small for the footprint. (adding mud around it)
- Having to cut down a pan when too large and changing the slope.
- Shimming or leveling sub floor to make it work.
So while there is the good points to the preformed pan like being light weight, strong, quick etc… a competent installer has to be aware of all the loop holes as well. Some of the inexperienced guys just don’t know all of them which can leave a botched installation at the part that’s hardest to fix if there’s problems.
On the flip side, a mud floor does take longer to do and needs some time to cure. Overall you do have a larger selection of drains which can be a huge thing depending on the site conditions and plumbing that’s being adapted to. If a joist is in the way which means the drain may be an inch off center, many times that illusion can be made up for in the tile layout all while not weakening any structure. You also have different options with waterproofing products which can vary depending on the situation.
Make sure that your shower quote has a flood test proposed. Whether a preformed pan or mud pan is installed… flood testing a shower is a proper step to ensure that the waterproofing products are working and holding water before tile is installed. There are plenty of contractors that feel the need to skip this step when a tile ready pan is used because of the built in waterproofing properties to the product. It’s not always the case because manufactured products can fail if there’s imperfections so it’s a good thing to be careful when working in the most commonly “leaked” room in the home.