Waterproofing & Shower Systems

As a rule, you want your shower or tub surround to be completely waterproof in any areas where water may hit. If not watertight, you run the risk of mold and mildew growing, which can lead to serious structural damage in your home. A poorly installed shower can cause over $10,000 in damage once it fails.



There are several different ways to build a shower. On this page, you can compare and contrast several waterproofing systems and methods to choose which is best for your installation.


Live in Alaska? We can ship a waterproofing kit to you! Click here for more information.


Click here to sign up for one of our free DIY-friendly shower installation classes.

Polystyrene Shower Systems - Wedi and HydroBlok

Wedi Shower System is in stock in Kent; just a short drive from Auburn, Federal Way, Renton, and Seattle

Prefabricated wallboards, benches, recessed niches, shower curbs, and  shower pans are made from a waterproof high-density polystyrene foam and coated with mesh and concrete for easy tile installation.


The key to the Wedi and HydroBlok systems is the incredibly strong polyurethane caulking, which coats every seam to seal the components and give you an easy, completely waterproof shower.


Learn more on our Wedi page and our HydroBlok page.


+ Fast & Easy: These systems have the fewest steps and the fewest components for a quick, simple installation. You can build an entire shower stall in under an hour and tile same day!


+ Completely Customizable: You can easily build a completely custom shower, purchasing only the components you need for your specific installation.


+ Lightweight Materials: Without any heavy cement board or mud pan sand mix to haul around, preparing for your installation is a much less strenuous process.


+ Instructional Videos: The  complete official series of instructional videos on installing the Wedi system and HydroBlok are on YouTube..


+ Numerous Prefabricated Options: You can purchase a preformed ADA-compliant wheelchair ramp, recessed niche, shower curb, bench, curved wall, nautilus-shaped shower pan, steam rooms, and more!


- Cost: The Wedi and HydroBlok systems usually cost more than other shower systems.

Schluter Kerdi Shower Kits

Schluter Kerdi Shower System is in stock in Kent; just a short drive from Auburn, Federal Way, Renton, and Seattle

Order a complete kit of all the components you need: pre-fabricated shower pan, shower curb, seals for the showerhead and pipes, corners, Kerdi band, and waterproofing Kerdi fabric.


The key to Kerdi is the polyethylene waterproofing fabric. Once your pre-fabricated shower pan is down and your wall board is up, the entire shower surround is coated with the Kerdi fabric and seamed with the Kerdi band for a watertight installation.


Learn more about Schluter Kerdi!


+ Cost: Usually less expensive than a comparable Wedi system.


+ Easy Bundles: Comes in a complete kit with all of the elements included. 


+ Instructional Videos: Schluter has a complete series of instructional videos on installing the Kerdi kits.


+ Designer Friendly: Easily configures to any shape or size shower installation. Simply build whatever elements you want, then apply fabric, and you have a completely custom, waterproof shower.


+ Better Line Drain: The Kerdi Line system requires fewer cut tiles and more flexibility than Wedi's Fundo Riolito system.


- More Steps: More steps and more time involved than with the Wedi system.


- Cost: Though less than the Wedi system, it is still more expensive than a traditional mud pan and vapor membrane.


- Extra Materials: In addition to the kit, you will need to buy wall boards and a specific thinset to apply the fabric to your wall boards.

Vapor Barriers, Cement Boards, and Mudsets

A cross section of a mudset shower pan.
A cross section of a mudset shower pan.

This is the oldest and most traditional method for waterproofing and building a shower.


A traditional mudset pan involves many steps and special materials (20-30 different items), and will take at least three days to complete. Due to the complexity of this project, we do not recommend this method for home owners or do-it-yourselfers.


Waterproofing wall boards above a shower pan or bath tub can be a very simple and easy process. We recommend RedGard, a rubbery coating that is painted on the concrete wall board to create a waterproof surface; this process usually takes a few coats and several days for dry time. You can also use a waterproofing fabric such as Schluter Kerdi or Wedi Subliner Dry.


NOTE: Many tileable cement wall boards are water stable, NOT waterproof, meaning water will wick through and get to your wall studs unless you add a waterproofing layer.


+ Cost: The total cost of the components for a traditional mudset installation is cheaper than a full Schluter Kerdi kit or Wedi system.


- Complicated: This method has the most steps and the most components, meaning it has the most possible ways to go wrong.


- Time: Even if you cut corners, this method will take at least 3 full day of work and waiting before the shower is ready for tile. If installed according to Tile Council of North America's standards, this process should take 1.5 - 2 weeks to complete.


- No Warranty: Because you are using 20-30 products from dozens of different manufacturers, you have no coverage in the event of leaks. 


- Messy: A lot of mud, thinset, coats, mixing, and mess. 

More Information about Waterproofing

A Note on Water

Showerhead with water

H2O is a determined little molecule; if it can find a way to get through your grout, past your tile, and into the structure of your house, it will. That's why water-proofing your shower installation is so important: if you don't do the job right, the water damage four to eight years down the road may be irreparable.

One common misconception is that if the building materials are tightly set, then water can't get through. Water will in fact use even the tightest cracks and crevices to creep and work its way out in what's known as the Wick Effect. Each time the water creeps in (each time you take a shower, for example), it will open the crevice a little more and leak exponentially faster.  The smallest crack or unsealed area will spell disaster. That's why you need a completely watertight system that will allow for no absorption or leaks.

What's the difference between "waterproof" and "water stable"?

Some products, such as cement board, are water stable. This means that they will not warp or fall apart if exposed to or submerged in water, much in the way that plywood or drywall would. But they are not waterproof: water will still penetrate cement board. If all you have between your shower water and your wall studs is cement board, water will get through and cause mold and mildew.


Waterproof materials, such as Wedi board, Kerdi fabric, or rubber membranes are non-porous and will not allow water through.

I have a non-porous tile and non-porous grout. Do I still need to waterproof my shower?

Yes. Tile and grout should NEVER be relied upon to waterproof a shower installation. Even the highest quality and most pore-free tiles and grout were not intended by their manufacturers to be a waterproofing material. There is still a chance that your grout can separate from your tile, creating a tiny leak that can cause huge problems. Even slab walls need to be seamed in the corners, and those corner seams could fail in time. A waterproof substrate is required for ALL shower installations.

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