These Cedar Park, TX, homeowners wanted to transform a boring builder grade guest bath into a designer showcase. But they didn’t want to spend a fortune. They therefore settled on natural stone marble tile for their renovation. Marble tile is a finicky material that requires skill and patience. This post describes how to install a marble shower for great results.
The Before
This was a typical builder grade guest bath. The fixtures were basic, the lighting minimal, and the tile was dark and pretty dreary.
The good news? It’s easy to make a bathroom better when the bar is set real low.
The Plan
This was another tub to shower conversion project, with everything going down to the studs. Ripping out everything is almost always the most economical remodel approach when your wish list includes rewiring for added fixtures and replumbing to move drain lines etc. Here were the clients’ goals:
- Convert the tub to a walk-in shower
- Replace the bathroom floor tile
- Replace the vanity with an open cabinet and double sink
- Replace the exhaust fan and add ceiling lighting
- Brighten the space with light tile and paint finish
Did everything go to plan? Read on to find out!
Step ONE: demo and replumbing
Demolishing the tub surround tile was easy, because the previous installer had done a pretty slapdash job. You want to use a quality modified thinset, backbutter each tile, and use concrete backerboard for a substrate to properly install a large format tile tub surround. You do not want to use plain unmodified thinset on drywall for ceramic tile with no backbuttering (unless you want to make a future demo really easy).
Since this was a tub to shower conversion on slab, the drain line needed to be uncovered to replumb with a 2-in p-trap. That’s the major annoyance for doing shower conversions on a concrete slab foundation. You will need to do some jackhammering. Here’s what the process looks like:
As you can see, it’s dusty dirty work to properly trench and replumb a 1-1/2in tub drain for a shower. You cannot however skip this step. If you do, then you’ll end up with a major plumbing code violation and a new shower that’s likely to back up and overflow.
Step TWO: framing and waterproofing
You never want to miss an opportunity to make a custom tile shower more usable and attractive with a nice niche design. The long wall of this shower only had a closet on the other side, and it wasn’t load bearing. So it was easy to reframe for a nice dramatically wide inset niche.
You also at this stage want to add some wall framing where the shower curb will be. This’ll make it easy to install a frameless glass shower enclosure once the tile is done.
And finally, think carefully about shower curb placement when converting a tub to a custom tile shower. Standard bathtubs are 30-in wide. However, a walk-in shower wants to be at least 32-in wide to not feel cramped. Remember that tub surround showers use vinyl curtains to keep water in. It’s not a big deal if your elbow hits a shower curtain. It’s real painful to smack your elbow on a shower glass enclosure. This is why these clients chose to cheat the shower curb a few inches towards the toilet location to make the final finished shower footprint 32×60-in.
Waterproofing was a combination of RedGard for the walls and Schluter-Kerdi for the shower base and curb. This is my preferred shower waterproofing method. It puts a seamless layer of waterproofing directly underneath the entire surface tile/grout layer and will last a literal lifetime if properly installed.
Natural marble tile is a particularly thirsty stone. When you install a marble shower, you need bulletproof waterproofing if you want the shower to last for decades. Kerdi and RedGard are great for this type of natural stone tile application.
Step THREE: shower tile install
There are three key tricks to install a marble shower so that it’ll last a lifetime and not look like slapdash shit in the meantime. The first is to use a high quality modified thinset and take time to backbutter each tile before install.
backbutter the tiles
Natural marble is a very thirsty stone. You won’t get good adhesion by simply slapping tiles on a wall of spread regular thinset. The marble will suck moisture from the thinset and prevent it from curing properly. Modified thinset will help this. But the real trick is to burn a thin layer of thinset directly onto the back of each tile with a putty knife before embedding it. This will push thinset into all the small cracks and pores, and create a strong thinset to thinset bond on the walls.
Marble is also a semi-transparent stone. So be sure to use white modified thinset for your install. Grey thinset can make the marble tile look dark and lifeless.
plan carefully for “random”
Any natural stone tile will vary from one box to another. Stone comes from quarries, and the shading and color will vary from one quarry to another. You can’t depend on just random chance to ensure that a final pattern will look truly random. For example, you might end up installing several boxes of dark tile in a row. This wouldn’t look good for a finish.
That’s why it’s imporant to unbox and inspect every marble tile lot that you’ll use, and preplan the install so that you get a truly random looking result. I like to randomize the veining in natural marble tile, but I actually work to NOT randomize the shading. You can get a really nifty effect by putting most of the darker tiles at the bottom of a wall and using increasingly lighter shaded tiles as you work towards the ceiling.
use whole tiles for the corners
It’s especially important to take care with corners when you install a marble shower. Marble tile is a strongly veined and shaded natural stone. Marble stone tiles are like snowflakes. No two are identical, and most are very different from one another. So you can’t put two random pieces together in a corner and expect a good result.
Instead you need to keep track of corner tile pieces so that each wall tile matches up with it’s corresponding piece. This is how you get a seamless result that avoids mismatched corners.
You can’t leave the tile to chance when installing a marble shower. Matched corners and a truly random seeming layout actually requires careful preplanning.
Step FOUR: the rest of the bathroom
Finicky vanity cabinets with drawers and open towel storage also require careful planning. Designer vanity cabinets need drain plumbing outlets and water supply inlets to be installed to tight tolerances. Otherwise the drawers won’t work and the pipes will be exposed.
Even more planning is needed for wall paint colors. Getting a theme here? Full bathroom remodels require lots of decisions, and a lot of these decisions can be difficult to change after the fact. That’s why I’m a big fan of making decisions incrementally as you work through the project. For example, it’s a very good idea to wait until the tile is mostly installed before settling on a wall paint color.
Here are some more pics of the final install process. This bathroom got new floor tile, added lighting and outlets, new paint and trim, and a fancy new double sink vanity in addition to the marble shower install.
This was a very marble bath! Using natural stone marble with added overhead lighting was key to making it not seem monolithic. Natural marble has a nice soft look with proper dimmable lighting and neutral wall/trim colors.
The Finish
Remember that this bathroom started out dark and cramped. Just about any renovation would have been a usability improvement.
These clients’ new marble tile bath was brighter and more useable. And, with proper waterproofing, it’ll last a literal lifetime. This is how you install a marble shower bath!
