Schluter: creativity, craftsmanship, and a complete installation system lead to stunning project

This project feature reinforces our understanding of some market trends, while demonstrating unique installation methods and the timeless value of craftsmanship. It begins with an addition to an older couple’s home that includes a spacious new bathroom. The modern appointments of a tiled shower and heated floors are to be found, but there are some twists that make the project particularly interesting.

Corona installed the Schluter®-DITRA-HEAT system to provide floor warming throughout the bathroom and ensure a lasting tile application.

The builder and the tile contractor

Case Builders LLC of Lutherville, Md., specializes in design, consultation, and fine construction. They manage a multitude of projects of varying levels of complexity throughout the Mid-Atlantic and represent their clients’ construction interests throughout the United States and abroad.

NTCA member Corona Marble & Tile of Woodbine, Md., is a family-owned tile and stone contractor established in 1985, that serves the Baltimore, Annapolis, and Washington D.C. areas. Led by second generation owner/installer Mike Corona, the company takes pride in its ability to collaborate with owners, builders, designers, and architects and successfully complete intricate projects that demand the highest attention to detail. This commitment to quality and longevity is evident in Corona’s employment of Certified Tile Installers (CTIs). For more information on the CTI program, you can visit ceramictilefoundation.org.

floor warming was installed throughout, using 3-2-3 cable spacing to maximize the warmth provided by the system


Calacatta Gold stone tiles supplied by Chesapeake Tile & Marble of Owings Mills, Md., were installed throughout the 15’ x 9’ bathroom, including the
6-1/2’ x 5-1/2’ shower. This white marble with deep gray veining produced a classic look that was very much at home in the open space with large windows and abundant natural light.

Heated floors

One of the primary homeowner requirements was to ensure comfort by incorporating a floor-warming system under the tiles. The addition was built over a crawl space so the system helps to mitigate transfer of cold from the space below. 

The framed shower floor area was built 2-1/2” lower than the rest of the addition to allow the mud bed floor to be flush with the bathroom floor.

Corona installed the Schluter®-DITRA-HEAT system to provide floor warming throughout the bathroom and ensure a lasting tile application. The DITRA-HEAT-DUO uncoupling membrane features studs on the surface that secure heating cables without the use of clips or fasteners and a thermal break attached to the underside. The cables were placed wherever heat was desired and the tile was installed directly over the membrane without encapsulating the cables in a self-leveling underlayment, thereby significantly reducing installation time. The sub assembly consisted of engineered wood joists covered with a 3/4”-thick AdvanTech® subfloor, and 1/2”-thick plywood underlayment to support the stone tile installation.

Curbless shower 

The entire shower base was covered with the Schluter®-KERDI waterproofing membrane after the floor warming system was installed, per Schluter Systems instructions.

Curbless showers continue to grow in popularity for both practical and aesthetic reasons. They can make a space feel more open, and the ease of entry can help homeowners age in place if desired. Since the bathroom space was part of an addition to the house, the builder was able to plan for this from the outset. He recessed the floor joists within the shower area 2-1/2” to allow for slope to the drain without requiring extra buildup of the floor outside the shower. Corona floated a mortar bed sloped to the Schluter®-KERDI-DRAIN in the center of the shower. Since there would be no curb, it was simple to continue the DITRA-HEAT-DUO membrane and heating cables across the shower entrance and over the surface of the mortar bed. While the uncoupling membrane is itself waterproof and the heating cables are rated for wet applications, the entire shower base was covered with the Schluter®-KERDI waterproofing membrane per Schluter Systems instructions. The walls were constructed using Schluter®-KERDI-BOARD as a lightweight and easy-to-install alternative to backerboard covered with a membrane.

Floating shower bench 

The floating bench is a 76” long 3 cm-thick marble slab supported by hidden steel brackets.

Shower benches serve practical purposes in tiled showers, and the sleek appearance of a floating bench can make for an elegant design feature. The owners desired a single piece of stone spanning the full length of the 76” wall without visible supports. 

Corona met this challenge using a clever approach. An approximately 12” wide strip of foam board was removed from the length of the wall and iron L-shaped brackets, 12” long on each side, were fastened to solid blocking within the wall framing. The previously-removed board was routed using the brackets as a guide and re-installed so that it would again sit flush with the rest of the wall. Special care was taken to waterproof the area around the brackets and prevent any water infiltration into the wall cavity. A 3 cm-thick marble slab with 4” deep mitered face was installed, with the underside subsequently covered with a layer of foam board and porcelain tile. The brackets provide the necessary support and are invisible within the final application.

Supports for the slab bench were anchored to the framing and then covered with Kerdi-Board building panels that had been routed to fit flush over the brackets.

Arched entrance

Field tile was cut and aligned to fit the underside of the arch and maintain the veining for a seamless, dramatic effect.
There are knee walls on either side of the opening, with an archway above that nearly reaches the ceiling

Perhaps the most striking visual feature of the shower is the entrance itself. Corona is particularly proud of this aspect of the project and rightfully so. There are knee walls on either side of the opening, with an archway above that nearly reaches the ceiling. He painstakingly cut and aligned field tile to fit the underside of the arch and stone chair rail to form the casing. The tile was installed so that the veining in the Calacatta Gold follows the arch to dramatic effect.


This project is an excellent example of how homeowners, builders, and tile setters can work together to produce something really special. The clear communication of requirements by the homeowners, followed by excellent planning and execution by Case and Corona Marble & Tile was the key to success. Using a complete system per manufacturer instructions, combined with plenty of creativity and craftsmanship helps empower tile setters to produce functional, durable, and beautiful results, all within a profitable business.

New Solutions From Infinity Drain Help Simplify Shower Installation

Infinity Drain, the manufacturer at the forefront of architectural and decorative drains for both indoor and outdoor applications, continues to offer innovative solutions that simplify the installation process. Below highlights the brand’s latest introductions offering added efficiencies and flexibility for installers:    

Universal Infinity Drain® Linear Drain Compatible with all waterproofing methods, the  new Universal Infinity Drain® Linear Drain is designed to adhere to both modern and traditional waterproofing techniques.  

Universal Infinty Drain Linear Drain

Infinity Drain® Slot Linear Drain Designed with a 3/8″ drainage gap, the Slot Linear Drain virtually disappears into its surrounding opening up the shower floor for an uninterrupted shower design.  

Infinity Drain Slot Linear Drain

Infinity Drain® Stainless Steel Shower Base The new Stainless Steel Shower Base is guaranteed for life against waterproofing failure and drastically reduces the time and materials required to install a new bathroom shower. This game changing solution comes ready to tile and is pre-sloped, eliminating additional time-consuming steps traditional shower installation requires.  

Infinity Drain Stainless Steel Shower Base

Infinity Drain® Site Sizable Low Profile Linear Drain The Site Sizable Low Profile Linear Drain allows for a seamless barrier-free shower design. The drain’s lower profile helps minimize the floor height needed to achieve a curbless entry.   

Infinity Drain Site Sizable Low Profile Linear Drain

Infinity Drain® Matte Black Finish Infinity Drain is now offering its Matte Black finish option across its collection of drainage products. To maximize corrosion protection and abrasion resistance, Infinity Drain achieves its Matte Black finish with an e-coating paint process that incorporates nano-ceramic technology.     

Infinity Drain Matte Black Finish

Functionality, technology highlight shower system developments

If there’s a project that requires expert engineering, it’s a shower system. Steam showers, whole-room, European “wet rooms,” barrier-free/zero-entry showers, evolutions in drains that include linear drains, tileable drains and wall drains all bring functionality and style to showers – as well as learning curves for installers. Improper slope, leaks and moisture vapor are bad news for any type of wet install, from rot to mold proliferation to discoloration to deterioration.

Shower systems depend on expert waterproofing, but more and more manufacturers have been developing lightweight modular panel systems that integrate waterproofing into the backer and pan elements.

In recent years, some of the most innovative examples of performance engineering have occurred within the shower systems category, featuring systems that form waterproof, functional, high-performance backdrops to attractive combinations of stone and tile. The following products are some examples of these new and interesting innovations.

Julia Billen

Shower systems have seen a lot of developments in the last few years but something that we’ve observed has been a shift toward shower waterproofing systems that incorporate a prefabricated shower pan, said Julia Billen, Owner and President, WarmlyYours Radiant Heating. 

This system type offers several key advantages over traditional mud beds, she added, such as weight reduction (particularly important for non-slab subfloor installations), speed of install (since you don’t have to wait for a mud bed to fully cure), and a consistent slope towards the drain (something that is difficult to achieve by hand without exceptional skill and patience).

“Prefabricated shower pans also offer a distinct advantage when combined with electric radiant heating systems as their dense foam construction typically has an inherent degree of thermal resistance (or R-value),” concluded Billen, “meaning they won’t absorb the heat from heating elements and negatively impact energy efficiency.”

Shower Systems

1 Custom Building Products

A polymer-modified, pre-blended, cement-based mortar bed and sloping mortar for fast-track leveling and ramping, Custom’s SpeedSlope Rapid Setting Sloping Mortar and RedGard® SpeedCoat™ Rapid Curing Waterproofing Membrane are designed to make shower installations fast and easy, with Speedslope setting in 1-2 hours. RedGard SpeedCoat is a ready-to-use, liquid-applied waterproofing membrane that cures in about an hour, even in cool or damp conditions, due to cross-linking moisture cure technology. Together, these two products allow installers to float a shower floor, waterproof, flood test and set tile in hours rather than days. custombuildingproducts.com  


Hydro Ban® Cementitious Waterproofing Membrane is a single-component, polymer-fortified cement-based waterproofing material that requires only water for mixing, resulting in a faster preparation process. It’s suited for use in applications such as swimming pools or waterproof spas. Formulated to be GREENGUARD Certified and LEED compliant for sustainable building, it’s equipped with anti-microbial technology and is solvent-free and non-flammable. laticrete.com


Mapeguard WP waterproofing membrane systems are engineered to deliver waterproofing, crack-isolation and vapor-control solutions, addressing the demands of wet and high-moisture environments encountered in both ceramic tile and stone installations. Mapeguard WP systems can include Mapeguard WP 200 waterproofing sheet membrane, Mapeguard WP ST waterproofing sealing tape, Mapeguard PIC pre-formed inside corners, Mapeguard POC pre-formed outside corners, Mapeguard PC pre-formed pipe collars and Mapeguard VC pre-formed valve collars. Components of Mapeguard WP systems can be purchased individually or collectively as the Mapeguard Combo kit (which consists of inside and outside corners, a pipe collar and a valve collar). mapei.com

4 Noble Company

Adding storage space within a shower environment is a convenient way to organize the essentials used including soap, shampoo, conditioners, shaving elements, and more. Noble Company offers a wide range of preformed, waterproof, ready-to-tile niches to meet this need. Custom sizes and configurations can also be accommodated through special order. In addition, Noble Company’s FreeStyle Thin-Bed Drain (pictured) is designed as a complement to its ProBase® II Multi-Slope Base system. The drain incorporates a clamping ring to provide for a high-performance mechanical attachment of the membrane to the drain. In addition, the drain is created to be low profile, making it a solution to a barrier-free installation. Drain bodies are available in either PVC or ABS and the strainer is available in four finishes. noblecompany.com

5 Progress Profiles

The company’s Proshower System is designed to be the solution for linear drain showers. Proshower Panel Linear is an isolating pre-sloped shower pan that facilitates tile installation by providing an optimal pitch for efficient water drain. Proshower Panel Central is the new shower tray with a 150mm diameter central hole for the positioning of Proshower Drain Kit. Two different shower channels that avoid malodorous stagnation are equipped with 360° adjustable drain and removable head flanges for connecting two or more shower channels. The Proshower Profile line offers profiles in a range of designs that finish the outer edges of the shower tray and hold the shower glass. progressprofiles.com

6 Schluter Systems

Relocating a drain for a shower can be extremely challenging and expensive in many renovation situations like slab-on-grade construction, basements and buildings with suspended concrete. To overcome these challenges, the company has developed the KERDI-DRAIN-H with a 2” horizontal outlet that allows the drain to be connected to an existing drainpipe and P-trap away from the new drain location, reducing cost of the project. In situations where there is no access to the space below the floor, the horizontal drain outlet is designed to make an almost impossible project a reality. schluter.com

7 WarmlyYours 

The WarmlyYours Shower Waterproofing and Floor Heating Kits are among the first in the industry to combine all of the elements of a shower pan waterproofing kit with a pre-sized electric floor heating system. The shower pan, which is pre-sloped, eliminates the need for a traditional mud bed, reducing installation time and effort. The company’s shower kits also feature an integrated hair trap in the drain assembly, a stronger drain flange, a wide variety of available grate covers and a dense shower pan. warmlyyours.com


Tom Cravillion

Tom Cravillion
Cravillion Tile & Stone
Plymouth, Wis. 

Cravillion walks us through a traditional master bath install and a renovation using state-of-the art systems and products. He shared that construction in his Eastern Wisconsin market is robust with more new construction start-ups in the mid-range homes and remodeling going strong as home values keep rising along with demand. He reports that labor rates are strong as well. $75-125/hour is not uncommon. – Ed.

We have just recently completed a large master bath renovation in which the 15-year old shower system failed. We installed it according to the written specifications at the time using a traditional water-in-water-out clamp ring assembly with a plastic weep hole protector as specified. The weep holes plugged and water flowed up and over the liner/curb system and flooded the floor/ceiling of the lower level bath. Insurance covered the entire renovation as the existing stone tile could no longer be acquired.

This time we used a major manufacturer’s full warranted system: bonding flange-style drain, mud-pack floor, water/steamproof wall board, ANSI 118.15 large-and-heavy-tile mortar, and epoxy grout. All tile on the walls are a 32” x 32” porcelain with 1/16” grout joint; shower floor is a mesh mosaic; main bath floors are 6” x 48” wood plank tile with 1/8” grout joint over an uncoupling membrane. Lippage-control devices were used as well to keep everything flat. For peace of mind, the mortar bed cured for one week, membrane for one week, four-day flood test with only evaporation loss. 

We think this is the way of the future for worry-free installations. Yes, it costs more, but how much value is a leaky shower system? We use this system almost always when it comes to installing high-end tile and stone. Our estimates are not competitively bid; we get our work through our local reputation along with a very high-end tile store.