Ventilation and proper waterproofing.

yeah, I during this project I am definitely going to install one of those vent fans with humidity sensors. I think is a must have with the Austin Humidity.

In my experience, if tile has mold, the area behind the tile was not waterproofed.

In the old days, tile was often applied to sheet rock. Grout was porous and wicked water to the sheet rock. Now the Sheetrock is damp, thus the mold.

I would put money on them not waterproofing when this bathroom was renovated. I repaired a lot of water damage when I removed the popcorn ceiling. I'm sure it will be nasty when we open up that wall. All the renovations done on this house seems to have been done cheaply and only surface level.

So what are the best practices for water proofing? I'm tempted to use the same materials used for steam rooms. I want to build a steam room myself in a few years, and it could be good to get practice with the materials. Likely overkill, but I usually go over kill lol

Over kill is never bad but Schluter makes a great waterproofing product called Kerdi and they have a great you tube for install instructions. A stem shower will require a much different install and IMO at the time you are ready for that this shower will need to be gutted

Hi Patricia

This is for the guest bathroom. The steam shower would be in the master. I'm hoping to never have to redo this bathroom while I live here

I recommend using a waterproofing system your contractor is familiar with. There are industry standards. TCNA and ANSI.

All details are covered in the industry bible. Buy one and familiarize yourself. Ventilation is required by the building code.

https://www.tcnatile.com/products-and-services/publications/218-english-publications/188-handbook/960-2019-tcna-handbook-for-ceramic-glass-and-stone-tile-installation.html

Have "tiles" cut into a Corian sheet. No mold or mildew ever.

@Joseph Corlett, LLCoseph, how expensive would that be? And how would you go about getting that done?

As this is the guest bathroom, I don't want to go super high end with it.

@User my "contractor" is my father in law who has done a LOT of remodeling with a family friend who builds houses. The labor is my husband, my BIL who used to hang drywall professionally, and myself.

@User I definitely will check that out!

Waterproofing is a must, but that won’t stop the tile/grout from getting mold from humid wet conditions. Good ventilation and drying the tile after a shower would be ideal. Maybe someone can recommend a waterproof grout.

Consider:

Using a system that has a surface applied membrane. That'll minimize the ability of the assembly to hold moisture, and the tray will be properly pitched.

Using a quality porcelain tile.

Using a single component grout. FusionPro or equivalent.

Using proper ventilation.

"@Joseph Corlett, LLCoseph, how expensive would that be? And how would you go about getting that done?"

You'd have to let a solid surface fabricator know you're serious and have a realistic budget.

lol what defines realistic budget? it would be hard to justify paying 1000 more than an off the shelf surround for something that custom.

Corian is a great product. It’s NSF certified for hospital use and food preparation areas. Unlike acrylic or cultured marble, it’s a renewable surface. Meaning that because it is solid all the way through, if it’s ever scratched, it will buff out. It runs $40-$70 a foot installed by a certified fabricator, depending on pattern. It’s a lifetime solution, with a low lifecycle cost compared to other materials that will be one damaged and age out.

A properly tiled shower is also a lifetime solution. It’s just much much harder to find the professionals that know how to create something to standard. There are a lot of tile hacks out there. Because Corian trains their fabricators directly, you have a much higher chance of a successful project with it. There are Certified Tile Installers that are tested to a industry standard of knowledge and skill. They’re very much in demand. https://www.ceramictilefoundation.org/find-certified-tile-installers

ok, so that would put my project between 1500-5000, depending on the size of the tub, the height of the surround, and if I wanted it one the ceiling. Do able.

Swanstone is a moderately priced solid surface material, targeted to the DIYer. You might investigate using their products.

https://www.homedepot.com/p/Swan-36-in-x-36-in-Solid-Surface-Single-Threshold-Shower-Pan-in-White-SF03636MD-010/202508842 

I have looked at that one! I've considered that as an option but I want a tile look, but not subway or square tile. But I've thought it is a good option if I couldn't find a tile installation I liked. I just would need to figure out other design elements to make it more interesting.

I have been thinking I might just need to suck it up and go with the subway tile. It's just so versatile. Even if it falls out of favour for a bit for being overused, It'll come back in style soon enough.