Facts About Waterproofing Your Shower Walls

June 2, 2020 | Starr Tingle

Waterproofing Behind Your Tile Walls

Waterproofing your bathroom can be overwhelming. These facts about waterproofing your shower walls will give you all the knowledge to complete your bathroom.

Personally, I think picking out tile is one of the most fun parts of remodeling a bathroom. For years I just didn’t give much thought to waterproofing behind the tile walls and left it up to the tile setter. Then Tony and I decided to remodel our master shower… 

Our shower was only seven years old, but the mildew was rampant. We cleaned and scrubbed and redid the grout constantly. We would set fans up to blow on it during the day to dry it out. Still, the mildew persisted.  

It was January, and we had a little extra time on our hands, so we ripped out the old shower, and we were a little stunned at what we found. The floor of the shower had been done with the “mud bed” method and the walls had concrete board behind the tile.

Let me explain the mud bed floor: rubber membrane goes on the subfloor of the shower and runs up the walls about 24 – 30″. Then, on top of the rubber membrane, they make a mixture of portland cement and sand that is thicker around the edges and slopes down to the drain in the shower’s middle. Tile and grout go on top of the cement mixture.

The walls of the shower had concrete backer board screwed to the framing. Tile and grout were installed over the top of the concrete backer board.

The problem is that tile and grout themselves are not waterproof. The flooring must be installed in conjunction with a waterproofing system, or whatever is behind them is going to get wet.  

So when we pulled off the tile and started removing the cement mixture below, it was completely saturated with water that had no place to go because it was below the drain. So our greywater (water drained from your sink, shower, tub, and washing machine are considered greywater – it means it is used and thus gross) from out showers had slowly seeped through the grout until the cement under the tile was soaking wet. It couldn’t drain nor dry out. Hence the awful mildew.  

This post is all about waterproofing your shower walls.

What To Buy

At this point, we had been introduced to new technology, which we spent a fair amount of time researching and learning about. Two systems are the more prominent players in the market, Schluter and Wedi.  

Note: These are not cheap systems. I think they are a reasonable price for what they deliver, but if you are looking for super cheap DIY, you should wait until you save up the funds to do it correctly. I’ve written a blog post to help you save for a remodel, you can read it here!

What You’ll Get

What you’ll get with these systems is a preformed shower pan that slopes toward the drain, a prebuilt curb, the drain, waterproofing membrane for the walls and corners, and adhesive. It is a comprehensive system. Here is a link to one of the kits Schluter offers.

Where to Buy

Both products are readily available for purchase at tile specialty stores, big box stores, and online. If you are planning to purchase the product yourself, I highly recommend purchasing from a tile specialty store. The staff will be able to help you select all the components you need and the correct amounts, saving you trips and frustration (time is money!) when you are installing. If you are near me, in Louisville, Kentucky, I recommend Lousiville Tile and The Tile Shop.  

First Time DIY’er

If you are new to this process and plan to hire the waterproofing and tile setting out, watch YouTube videos. Schulter literally has dozens of videos showing how to properly install their waterproofing membrane. I’m sure Wedi does as well, Schluter just happens to be what I use, so I haven’t looked for Wedi. I want you to understand how the product works, so when you interview potential tile setters, you will be able to discern whether or not they know what they are talking about.   Note: Unless you are a seasoned DIYer, in my opinion, it is better to leave the installation of waterproofing systems and tile to the professionals.  

Seasoned DIY’er

If you are a hardcore DIY’er, watch the videos, plan hard, and give it a go! If you have a standard size shower, you can buy preformed shower pans that give you the correct slope to the drain. They are waterproof, so all your greywater will go directly to the drain. If you follow the directions and are handy, this would be hard to mess up. It is a very well thought out system.  

Once your shower walls are framed square and level (this is super important if you are installing large format tile) and your plumbing is roughed in, you will have mold-resistant drywall installed on the walls of your shower. Do not mud the drywall joints. The waterproof membrane then adheres to the drywall with adhesives sold in conjunction with the membrane. Know who can help you figure that out? That’s right, the employee at the tile specialty store!  

What to Avoid

*Mud Bed Installation – there is simply better technology that will increase the life of your shower by years.  

*Concrete Board – again, there is simply better technology that will increase your shower life and is much easier to install. The concrete board is unwieldy and requires special tools to cut.  

*Using a tile installer who tries to talk you out of using a Schluter type waterproofing system. 

* DIY’ing the waterproofing and tile in your shower unless you are a hardcore, and I mean really hardcore, DIY’er.  

This post is all about waterproofing your shower walls.


Wrap Up 

You guys! You are so much more informed about your bathroom remodel now that you’ve taken your precious time to read my blog. I am over here, rooting for you to have the most impressive bathroom remodel ever. It increases the value of your home and gives you joy every day!

I’m committed to educating homeowners and helping them love the process of remodeling their home. I believe taking the time to learn about the bathroom components will make your remodel go faster, smoother, and help keep costs down. If you have a specific remodel question, send me an email at Starr (at) starrtingle.com. I would love to help you out!

Be sure to follow us on Facebook @Sanctuary Homes, Instagram at @sanctuaryhomes, and Pinterest at Sanctuary Homes. THANK YOU SO MUCH FOR YOUR TIME!! Chow for now!