Several methods are available for installing a shower. The classic method is to float a mud bed, taking care to elevate the drain to the proper height, build in the correct ple-slope (1/4” per foot) and protect the drain’s weep holes with crushed rock or tile chips. Increasingly, younger installers are turning away from these older methods to full shower kits which are designed to be easy enough for a D.I.Y. audience to handle, though even the simplest systems will fail if the proper prep-work isn’t done.

No matter what method you use, manufacturers, installers and contractors all agree: Take your time and follow manufacturer instructions to the letter, don’t cut any corners, and when in doubt, consult the TCNA Handbook. We spoke with experts in the field to find out any other advice they’d be willing to share.

Mark Pennine, Ardex Americas:  “The preparation steps for a shower/wet area are the installation of a vapor barrier, cement board, fiberglass tape and a thin set such as Ardex X 77 Microtec Fiber Reinforced Thin Set Mortar​​​​​​ to address joints, shower pan, pre-float, mud bed and water proofing.”

He added that it is important that installers do their homework and know what installation products are appropriate for the tile chosen. “When installing vitreous tiles like porcelain or glass, it is important to use a highly modified thin set that meets ANSI standard 118.15​​​​​​. Also, not installing top-side waterproofing can often be overlooked or viewed as unnecessary.”

Jim Rodgers, A & J Tile Co.: “My go-to product is 8+9 from Ardex. It keeps the water from getting down in the mud floor. I really like it because you can roll it on, make it a little thicker. I pack my base and seams with it.”

He said working with a mud floor is a skill that takes many years to develop. “It’s very hard to do a mud floor; people assume it’s like pouring concrete. But the mixture can’t be too wet, and it’s a different type of cement. It’s hard for people to understand how to do it.”

Tom Cassutt and Mike Boenisch, Bonsal American/ProSpec: “If I would stress anything, it’s that the shower is not something you want to rush because of the sensitivity of water penetration,” Cassutt said. “If you’re putting down a waterproof membrane somewhere in the system, do not puncture it. If there’s anything that requires common sense, pre-planning and thought put into it, showers are it.”

Boenisch added, “If starting from scratch, the first thing is to make sure the existing substrate is structurally sound and will be able to support whatever weight you put over it. The second thing is make sure you select the right drain. The third thing is put in a pre-slope. A lot of the mud bed people automatically assume the mud is waterproof, but it will get saturated if you don’t have that pre-slope.”

Steve Taylor, Custom Building Products: “The size and type of tile matters in the context of the pre-slope, as larger format tiles require more cuts. Tile type impacts both grout and mortar selection. For instance, a large-format tile mortar may be required or a medium-bed mortar on a pebble-size tile.”

He also recommends understanding how the shower will be used. “Residential showers used infrequently have different needs than commercial showers, which could be used all day. Higher performance mortars and membranes must be used in these heavy-use applications.”

Roger Barker, Fortifiber Building Systems Group: “Our product Aquabar ‘B’ is used as a cleavage membrane/vapor retarder under floors and behind walls for wet-set mortar beds and behind cementitious backer units on walls. FortiFlash is used to waterproof around windows in shower and bath areas and over shower seats and the lip of tub and tile installations.”

Greg Mowat, Forensic Tile Consultants: “Make sure the weep holes are opened and protected. Make sure there is a slope toward the drain of the shower.”

Tom Plaskota, H.B. Fuller/Tec: “Know the compatibility of the materials involved. For example, mastics are not acceptable for bonding tile to membranes. Usually a mortar is required, and different membranes have different mortar requirements. Liquid membranes typically require latex-modified mortars but some uncoupling membrane manufacturers require unmodified mortars.”

“The Tec brand offers liquid-applied waterproofing membranes,” he added. “In most cases they are installed with basic tools such as a paint roller and brush or notched trowel.  For larger installations they can also be applied efficiently by spray with commercial airless sprayer equipment.”

Stan Young, Tile Setters Toy Store: “I’d love to see the industry change. There is some good talent out there, and I’ve seen some nice work. On the other hand, I’ve seen work that’s brutal. You can’t just take some guy off the street and expect him to know what he’s doing. It’s getting to be a lost trade.”

Miguel Cossyleon, James Hardie: “With a cementitious backer unit, you don’t really need any special tools to work with the product itself. It can handle most cuts with a standard utility knife. When you affix the product to the wall, you want to use a fastener – whether a nail or  a screw – that is rated to perform with moisture.”

“One of the common misconceptions is the formulation of the board,” he added. “It’s 90 percent cement and sand. That provides a greater prevention to permeability and superior bond strength.”

Jay Conrod, Laticrete:  “If you are installing a pre-sloped shower pan, it is imperative to “dry-fit” the pan to the installation site, making sure that it will fit the shower floor correctly. If not, resize the pre-sloped shower pan to fit the installation with the drain and waste outlet lined up.”

He stressed the importance of prepping the site. “Clean the site, making sure it is free of any dust, dirt and oils prior to installing any materials. Additionally, an installer should always consider waterproofing such as Laticrete Hydro Ban. In a shower installation, it makes sense not just to waterproof the floor, but also to waterproof the walls up to the shower head or preferably, to the ceiling.”

Gary Rossiter, Loxcreen: “Our ProVa-Shower System contains all the components required to build a fully bonded, water-tight assembly for tiled showers.”

He added that both the old and new methods of shower installation have their place. “The older guys still like to do their mud beds, but for the younger guys who maybe don’t understand all of those steps, these systems are an easy way for them to put in the shower and immediately install the tile.”

Cris Bierschank, Sam Biondo, Carlos Cano, Audrey Chapman, Leigh Hightower, Carmelo Pulvirenti, Amy Roseman and Jonathan Shoemaker, MAPEI:  “It is important for installers and contractors to be familiar with their state, county and city building codes in order to ensure compliance. In certain regions, it is the plumber not the tile installer that must complete the waterproofing. Also, some regions do not allow drywall in shower areas, even if they are coated with several layers of waterproofing. If the bathroom floor consists of plywood subfloor, consider adding a layer of cement board and then coat the cement board with a liquid-applied waterproofing membrane.”

The panel noted, “Don’t skip the step of treating cement board joints with mesh tape and thinset. Once the thinset has dried for 24 hours, then the waterproofing can be applied over the joint areas. If fabric or mesh is required, use the one specifically recommended by the membrane manufacturer.” When selecting a membrane, choose one that meets ANSI A118.10. “In steam shower applications, the use of a vapor barrier behind the cement board is also required,” the panel added.

Frank Canto, Canto Tile & Stone: “I see a trend approaching with the advent of roller-applied liquid waterproof membranes that dry like rubber and are compatible with direct bond of the tile, eliminating the rubber shower pan liner altogether. In my opinion this is a much better system because it is seamless with no more ‘tackling’ the folded liner in corners, seats and curbs.”

Canto also said it is important to protect the drain itself. “Make sure it is clear of debris and not clogged by a previous trade, because the tile man will be the first to be blamed. Remove the strainer and stuff a rag or a wad of newspaper into the throat of the drain assembly, reinstall the strainer and apply masking tape over the strainer to keep it clean and any debris from getting inside.”

Bryant Bouchard, Schluter Systems: “For a long time, contractors just like consumers thought that certain tiles or grouts are waterproof on their own. But these days, most contractors realize that you do need that extra waterproofing step.”

He added that the newer shower installation systems are designed to be easier to work with. “The old method isn’t bad, but it requires more skill, more time, and if you miss one step it could be a disaster. Products like our Kerdi-Board are designed to make it easier for contractors to do a shower without issues.”

Al DiBiccari, AD Ceramic Tile: “I think manufacturers have made it easier for both skilled and unskilled workers to do a shower and have it come out without any leaks. Personally, I still like the mud beds, but there are lots of people who are using the complete systems made out of foam.”

DiBiccari stressed the importance of prep-work. “We just took apart a shower and found a couple of inches of water inside the bench. The guy seemed to have wanted to do a good job, but he didn’t follow the directions. If you don’t plan out the process from beginning to end before starting, you’re going to have problems. You need to know where you’re finishing before you start.”

Steve Rausch, USG: “Cement board such as Durock from USG has long been the standard for most installations and requires only basic household tools to install, but many other options such as foam backer boards exist to meet different desires/needs/requirements exist. Many wet area problems can easily be avoided by selecting a complete system to install, such as USG’s new Durock Shower System.”

Michael Byrne, consultant and FCI columnist: Byrne writes, “Especially when installing tiles in a shower environment, a professional installer must be familiar with appropriate American National Standard Institute specifications (ANSI A108). ... Instead of tar paper or plastic film, surface-applied membrane systems offer a much higher level of protection.”

“The technology and materials needed to build trouble-free shower stalls and wet-area installations are readily available, but unfortunately, less effective installation methods and materials are still being used. This situation is so widespread that Bob Daniels (executive emeritus of the Tile Council of North America) and I have started a national inspection company to address this issue.”

Tim Levasseur, Wedi: “Ensure that the method you have chosen to employ in your endeavor is one you are familiar with or can access information on easily. Jobs can come to a standstill if questions need to be answered on the fly. Be sure to follow all steps and guidelines properly and most of all, perform and document a proper flood test.”

He added, “The older methods are still employed but we are seeing a shift toward the latter, respectfully. This has to do with the aging part of the workforce in contracting and an uneducated/younger part at the same time. Both tend to find products like ours useful and simple.”

Dan Welch, National Tile Contractors Association president: “When it comes to working with waterproofing membranes, you’re talking about making sure the water goes down the drain and not anywhere else. So getting the right amount of millage and installing it correctly is a big deal. With sheet membranes, such as those from Noble, you are always going to have some millage, and it’s important to account for that. I think sheet membranes are the best way to go, because with liquid-applied systems, you’re totally dependent on whose applying the membrane.”

He noted that consumers should always pick a contractor who is knowledgeable and trains his or her staff. “I would ask for an Advanced Certifications for Tile Installers (ACT) certified person to be doing my showers and membranes.”

James Woefel, NTCA first vice president: “For the shower pans I use Noble. If I’m doing crack isolation I use Custom Building Products’ RedGard. Those are probably the two products I use most on showers.”

Woefel said poorly installed showers are a major problem in the industry. “Showers are your biggest liability in installation, and as a tile contractor I would like to stop seeing these failures. The industry is getting a black eye, and as a result we’re all working for a smaller pie. Everyone having a bigger pie is what we should be focusing on.”


Other Shower Products

Steve Padgett, Dap’s Kwik Seal Grout Recolor Kit: “When using the kit, make sure the existing tile is sound. If tiles are pulling off or shifting, you will need a little bit more work around the shower area. If it’s a cosmetic issue – the grout is very dirty or discolored or you just don’t like the color, you can use our product to freshen it up.”

“When cleaning it, make sure you use a neutral pH cleaner,” he added. “If you’re in a commercial environment and using a really caustic cleaner, that’s going to affect it.”

Joe Phillips, Luxe Linear Drains: “The most common question is, if I have a 4’ shower, will a 4’ drain fit? My question back is, Is this the rough opening or the finished opening? If I’m talking to a contractor, that usually means it’s a rough opening. A 48” drain is not going to fit when you close it in with the tile. The next size down is 40”. Some may not think that’s ideal, but it’s far easier to put a 40” drain in a 46” opening, rather than trying to force in a 48” drain.”

He added, “We also make custom sizes, but it’s going to take a lot longer lead time. If you can, it’s better to accommodate the customer right off the shelf.”

Farrell Gerber, Tile Redi: “Our Redi Trench consists of a tileable shower pan with an integrated linear trench drain and also, the choice of either a tile-able linear grate or designer grate tops. Furthermore, contractors are able to offer their customers shower bases with single curb, double curb, barrier-free or ADA entrances.”