There’s no curbing the growing enthusiasm for curbless showers among leading designers, homeowners and commercial facility owners. The National Kitchen & Bath Association (NKBA) recently released its annual Design Trends study, which takes a deep dive into all aspects of primary bathroom design.  

The survey included 600 industry respondents across North America – two-thirds of whom are NKBA members – who shared their professional insights and experiences. Sixty percent were designers, with the remainder being showroom professionals, dealers, specialists, K+B remodelers, contractors and architects.

According to the report, there will be greater demand for primary bathrooms with many shower features for a spa-like feel and for aging in place in 2023.

Large two-person showers with open entrances will be popular as 55% of respondents chose no door - open entrance for shower door configurations. Curbless showers are the next evolution in the trend to create open entrance showers.

Here are four essential aspects to consider when planning for a curbless shower installation. Before we jump into the technical aspects, let's look at some of the advantages of using a linear drain for curbless showers.

The Advantages of a Linear Drain

According to the NKBA report, linear and square shower drains will be most prominent in 2023, with 78% of respondents choosing linear as their preferred drain option. Let’s explore why linear drains should be on your radar:

Ideal for ADA-compliant showers: Linear drains in curbless showers are the ideal design solution for creating ADA-compliant showers and wet spaces that are universally accessible. With only one slope and no barrier to cross, the floor easily accommodates a freestanding bench, a wheelchair or some other mobility aid.

Ease of installation: A linear drain offers ease of installation with a one-slope-to-one-plane: no four-way, compound slope, as with a conventional center point drain. As a result, installers spend less time at the consumer's home. For a typical center point drain, installation requires a two-piece clamping collar to be attached to the waste pipe, while a linear drain easily attaches directly to the waste pipe. QuickDrain can be installed by connecting to the drain waste line, or using a traditional 2-piece clamping collar drain body.

Complete water evacuation: Linear drains can also extend the shower floor's full length, thus promoting complete water evacuation in a curbless enclosure. Consequently, there is less chance of water pooling and running out into the bathroom. Shower floors without enough pitch usually puddle and hold water. Soap scum and water deposits form in these wet areas, making the tile and grout look dirty.

Large format tile: Linear drains open up new tile opportunities, especially large-format tile and solid surface materials, because the installer does not have to use smaller tile to accommodate a conventional, four-way compound slope. The use of larger tiles throughout the room results in fewer grout joints to impede movement or drainage while reducing the number of grout joints and seams where mold, mildew, and grime can take hold.

According to the NKBA report, 59% of respondents prefer large tile, so expect to see large format tile and slabs increase in popularity in 2023. Particularly, because they require fewer grout lines and maintenance.

Tips for Curbless Shower Design

As with any construction or remodel, if curbless showers are not correctly planned and designed, water will not drain properly or worse—leak all over the space. Properly installed curbless showers are beautiful additions to any home. 

To ensure correct curbless shower installation, keep the following four aspects in mind during your planning phase: 

1. Drain location

Installing the linear drain at the shower entry is the easiest installation for a curbless shower, because the sub-floor is not required to be recessed. The latter means there is no need to raise or lower the shower or bathroom floor to hide the slope.

Furthermore, if the drain is installed at the entry to a curbless shower, the shower’s flow rate capacity will drop down to five gallons per minute (gpm). Today's standard flow rates are well within this 5 gpm standard, most having been reduced to 1.5 gpm. However, you cannot have ceiling shower heads, body sprays, and hand showers all activated at the same time when your drain is located at the shower entrance, because their combined flow rate will exceed 5 gpm.

If you plan to install the drain against the shower's back wall, the shower pan will need to be recessed, or the bathroom floor will need to be raised to hide the slope. Although this type of installation will take more time, it is the best possible placement for effective drainage.

A back-wall drain install will handle up to 10 gpm, and is therefore the best location if multiple showers and hand sprays will likely operate at once. (See Figures 1 and 2 below.)

2. Subfloor material

Whether it be concrete or plywood, it is important to identify the subfloor material when planning a curbless shower. It will determine which product the manufacturer will recommend for your installation. 

For example, QuickDrain technical managers usually recommend a retrofit installation for a concrete subfloor, because it goes directly on the slab, and you need not trench out the concrete. 

Knowing the subfloor material beforehand will help the manufacturer determine the best solution for your curbless installation.

3. Type of linear drain 

The linear drain should extend from vertical surface to vertical surface (wall-to-wall). QuickDrain's trough extensions and covers can be trimmed at the job site after the drain body is installed, providing wall-to-wall coverage.  

Be sure that the linear drain has (1) integrated slopes to efficiently and effectively evacuate water from the drain body and (2) a drain that connects directly to the waste line. Stackable spacers will also allow you to easily adjust the drain cover after installation to ensure the drain cover is flush with the floor. 

4. Waterproofing

Whether it be a topical liquid, or a topical sheet, such as QuickDrain's waterproofing sheet membrane, be sure to confirm whether or not the linear drain can be used with the type of waterproofing you have selected. 

QuickDrain's integrated PVC linear drain, ShowerLine, combined with pre-sloped shower panels and waterproofing accessories, represents a total curbless shower solution for promoting effective and efficient drainage. 

Curbless showers fit in any home, lifestyle or décor. Every homeowner can reap the benefits of a curbless shower. Now that we have outlined the most important things to consider when planning a curbless shower, you are well on your way to ensure correct installation. 

The best place to start is to contact the manufacturer directly to be sure you have identified the best-suited solution for your location and plumbing configurations.