Building a Waterproof Shower
I think we can all agree the single most important thing to consider when building a shower is waterproofing. Building a waterproof barrier is an essential part of preparing these showers and unfortunately, many people do it wrong or cut corners. We all know countless shower pan and waterproofing horror stories.
And yet while clients ask a lot of questions during a bathroom remodel, one that never seems to come up is properly waterproofing the shower. Maybe they don’t understand the process — or maybe they just trust us to build and install our systems according to industry best practices.
But bathrooms are botched more than any other room in the house.
I know there’s a long list of things to think about in a bathroom remodel, but in my experience most consumers spend too much time and money on decorative features and fixtures and not enough on what goes on behind the scenes – the guts of the project that really affect the overall quality and longevity of their remodeling investment.
The Typical Waterproofing Process
The typical process is complex, but it’s not impossible to understand. Most shower installations used to involve copper shower pans, mud floors, cement backer boards, mesh tape, thinset, and liquid waterproofing sealer. Later, remodelers began installing PVC shower pan liners to eliminate the time and cost involved with mud shower pans.
Regardless of the exact details, a typical shower installation requires at least three tradespeople taking part in a 5-step process:
- The remodeler has to frame the walls
- The plumber has to install a drain and the copper pan or PVC liner
- The remodeler then applies the cement board
- The tile setter next installs the mud floor, and tapes and coats the cement board seams
- The remodeler applies the waterproof coating to the cement board and the mud floor
And yet the reality is that cement backer board, thinset mortar, and liquid sealers just aren’t fully waterproof, even after tile and grout are applied.
Albert Einstein was credited with the saying, “Insanity is doing the same thing, over and over, and expecting different results.” I often thought this process was insane, but didn’t have a better alternative until I learned about the Wedi shower system at a trade show.
WEDI Shower System
What we really wanted, and what our clients really needed, was a system that offered 100% waterproofing, minimized mold issues, saved time-consuming steps, and was easy to assemble at the job site. Here’s where WEDI fits in.
The WEDI Building Panel is a waterproof tile underlayment for walls and floors, manufactured in Emsdetten, Germany. It consists of an extruded, polystyrene core and is covered in a fiberglass mesh and polymer modified cement resin coating.
The core of the polystyrene panel is extruded under enormous pressure to create a dense mass of tiny, closed cells so tightly packed together that water cannot penetrate. Both sides of the panel have an outer covering with a glass mesh coated with a polymer-modified cement coating. The mesh and cement give the panel enormous strength.
The WEDI product is 100% waterproof, will not decay, and is easy to cut to any size with a utility knife. It is not necessary to use cement board /green board/drywall behind the WEDI panels.
We immediately noticed the speed that WEDI can be transported, cut, and installed. It’s much faster than conventional methods and saves money when compared to the many different tasks involved in waterproofing a shower.
WEDI Panel Sizes
The WEDI Building Panel is available in
- 2’x 4 ‘
- 3’x 5′
- 2’x 8”
- 3’ x 8’
- 4’ x 8’ sheets in various thicknesses
- 1 1/2″
Fastening WEDI Panels
WEDI panels come as thin as ½” thick and are fastened every 12 inches directly to wood or metal studs that are spaced 16-inches on center. Special washers are used with the fasteners.
1″ WEDI board can be applied directly to studs spaced 19” o.c. framework.
In comparing square foot pricing, the WEDI Building Panel is more expensive than cement backerboards and fiber-cement boards. However, in comparing value, WEDI Building Panel saves extensive labor, provides a waterproof substrate, is less likely to create an environment for mold, is a crack suppressor, and weighs 75% less than the other products mentioned.
Total job costs are reduced when using WEDI Building Panel when you consider the following other methods:
- Cost, weight and hassle of cutting cement board
- Cost of a traditional method includes a pre slope, shower pan liner, and mortar bed
- Cost of a plumber-installed drain and poly liner
- Time and cost of taping and thinsetting seams
- Cost of purchasing and applying waterproofing sealer
- Cost of waterproof membrane
Part of the cost savings that is not immediately realized by contractors is the speed with which a WEDI shower system can be installed. It took us one day to install this one versus the several days it would have taken using traditional methods.
The WEDI shower system installs faster and easier because it is lightweight, cuts with a utility knife, and needs only 1 fastener per square foot. The end result is a fully waterproof surface.
WEDI Fundo Shower Pan
The WEDI Fundo Shower Pan is 100% waterproof and pure genius. It is a prefabricated, presloped, tile-ready pan that is installed on a wooden or concrete subfloor using latex modified thinset mortar.
WEDI Building Panel used as waterproof backer board on walls connect into the shower pan shiplap notch which is prefabricated.
The best part is this pan is completely waterproof, eliminating the need to install a shower pan liner underneath. The shower pan comes with a pressure fitting drain system with no weep holes necessary.
The WEDI Fundo Shower Pan is tile-ready immediately after installation.
WEDI Fundo Shower Pan Sizes
One hidden gem with using the WEDI shower system and Fundo shower pan is the ability to install 2″ x 2″ or larger sizes on the shower floor.
The WEDI Fundo Shower Pan comes in the following sizes:
3’x 3′, 3’x 4′, 3’x 5′, 3’ x 6’ (center drain)
3’x 6′ (offset drain)4’x 4′, 4’x 5′, 4’x 6′, 4′ x 7′, 5’x 5′, 5’x 6′ ; 6’ x 6 ‘and 5’x 7′
These are the standard sizes which are equipped with a 4” x 4” stainless steel drain cover. Additional sizes are available featuring longer or shorter linear drain cover assemblies.
Extending the WEDI Fundo Shower Pans
WEDI offers a presloped extension panels that can be connected to the WEDI Fundo Shower Pan using a shiplap notch which is prefabricated into the extension panels. When panels are cut, the shiplap connection field cut [circular saw and utility knife] into the panel. WEDI Joint Sealant is then used inside the shiplap joint and an additional bead is applied on top of the joints with a putty knife to smooth the sealant over the joints and create a waterproof joint.
WEDI requires the use of a proprietary sealant, engineered for flexibility and waterproofing.
Note – for accessibility issues, the WEDI Lingo is a curb-less, sloped shower base ¾ inches thin at its perimeter and available in various sizes
Waterproofing the WEDI System
Once the pan, panels, and WEDI fasteners are installed, all seams are sealed and wall fasteners are coated with sealant.
With bathroom remodels, clients often focus on color, layout, and fixtures. While those are all important considerations, many times they’re missing the all-important conversation about waterproofing.
The Wedi shower system does everything we want it to do as a product and eliminates other the cost and hassle involved in traditional shower installations. This means we can get more done in less time – projects can be completed faster, which equate to more jobs and earning potential for contractors. Since it is fully waterproof, it also reduces callbacks and the risks of something going wrong.
The end result is a bathroom both client and contractor can be proud of.
Read our article on How to Plan a Bathroom Remodel
Wedi Waterproof Shower System Video Review