Whether it’s part of a complete wet room or installed as a standalone feature, a curbless shower combines easy access for those with limited mobility, convenience for other users, and a look that is trendy, sophisticated, and attractive.
The trick to installing one of these water features is to ensure the moisture stays inside the shower.
Once upon a time, creating a reliably waterproof enclosure for a curbless shower was no small chore.
It meant putting a lot of work into creating a custom shower pan. This kind of project was usually above the skill level or desire of the weekend DIYer, and it generally meant hiring a contractor.
Now you can buy curbless shower-pan kits that make installation a breeze.
The manufacturers have thought through all the issues that can arise and have developed the kits and shower pans to be as foolproof as possible, while also meeting prevailing codes and best standards and practices.
Installing a curbless shower using one of these kits is a realistic project for any home handyperson with even moderate DIY skills and a weekend to spare. These pans come with preconfigured slopes to ensure optimal drainage away from the shower’s edges.
The product we used for this project, the Tuff Form kit from Amazon, includes an offset drain hole that offers the option of rotating the pan in the event of a joist or mechanicals that are in the way.
This product is offered in nine different sizes and can be cut with a circular saw to just about any shape including more unusual, curvy shapes for a truly custom look. Curbless shower-pan manufacturers also sell pans with trench drains for an even sleeker look.
The pan we used for this project is typical of the prefab curbless pan construction; it can support 1,100 pounds even though the pan itself weighs less than 70 pounds.
It sits right on floor joists, with the addition of blocking to support the area around the drain and to provide nailing surfaces around the edges.
Kits like these offer advantages beyond the ease of installation and a thoughtful configuration of parts. Usually, the plumbing can be completely adjusted and connected from above, so you won’t need to work in the basement or crawl space, or open up the first-floor ceiling to install a second-floor shower.
The kits themselves generally include almost everything you’ll need for the installation.
TOOLS & MATERIALS
- Curbless shower kit
- Circular saw
- Jigsaw or handsaw
- Caulk gun
- Torpedo level
- Cordless drill and bits
- PVC cement and brush
- Speed square
- Putty knife
- Palm sander and 120-grit pad
- Rubber gloves
- Synthetic paintbrush
- Roller and roller handle
- Caulk/ construction adhesive
- Waterproofing tape
- Ear and eye protection
- Work gloves
WET ROOMS AND UNIVERSAL DESIGN
Because a wet room allows the bathroom to be designed with fewer barriers and a single-level floor surface, these rooms are natural partners to a universal design approach.
If you’re thinking about converting a bathroom to a wet room, it’s worthwhile to consider a little extra effort to make the space as accessible as possible for the maximum number of users.
Walls. Where codes allow it, consider using thick plywood rather than cement board for the wall subsurfaces. Plywood allows for direct installation of grab bars without the need for blocking or locating studs.
If you’re set on using cement board, plan out locations for grab bars near toilets, behind and alongside bathtubs, and in showers.
Most codes specify that grab bars must be able to support up to 200 pounds—which usually means adding blocking in the walls behind the grab bars.
Shower stall. One of the benefits of adding a curbless shower is easy wheelchair (or walker) access. For maximum accessibility, the shower area should be at least 60″ wide by at least 36″ deep (60″ by 60″ is preferable).
This allows a wheelchair user to occupy the stall with a helper. And, although the idea is a wide-open shower space, it’s always a good idea to add a fold-down seat. This allows for transfer from a wheelchair or a place for someone with limited leg strength and endurance to sit.
How to Install a Waterproof Sub-Base for a Curbless Shower
1. Remove the existing flooring material in the area of the shower pan (if you’re remodeling an existing bathroom). Use a circular saw to cut out and remove the subfloor in the exact dimensions of the shower pan. Finish the cuts with a jigsaw or handsaw.
2. Reinforce the floor with blocking between joists as necessary. Toenail bridge blocking in on either side of the drain waste-pipe location, and between joists anywhere you’ll need a nailing surface along the edges of the shower pan. If trusses or joists are spaced more than 16″ on center, add bridge blocking to adequately support the pan.
3. Set the pan in the opening to make sure it fits and is level. If it is not level, screw shims to the tops of any low joists and check again; repeat if necessary until the pan is perfectly level in all directions.
4. Install or relocate drain pipes as needed. Check with your local building department: if the drain and trap are not accessible from below you may need to have an onsite inspection before you cover up the plumbing.
5. Check the height of the drain pipe. Its top should be exactly 23⁄8″ from the bottom of the pan—measure down from the top of the joist. If the drainpipe is too high, remove it and trim with a tubing cutter. If it is too low, replace the assembly with a new assembly that has a longer tailpiece.
6. Lay a thick bead of construction adhesive along with the contact areas on all joists, nailing surfaces, and blocking.
7. Set the pan in place and screw it down using at least 2 screws along each side. Do not overtighten the screws. If you’ve cut off the screwing flange on one or more sides to accommodate an unusual shape, drill 1⁄8″ pilot holes in the cut edges at joist or blocking locations and drive the screws through the holes.
8. Disassemble the supplied drain assembly. Be careful not to lose any of the screws. Place the drain tailpiece on the waste pipe under where the pan’s drain hole will be located and measure to check that it sits at the correct level. Solvent-glue the tailpiece to the end of the waste pipe.
9. Position the supplied gaskets on top of the tailpiece (check the manufacturer’s instructions; the gaskets usually need to be layered in the correct order). Set the drain flange piece on top of the tail and into the drain hole in the pan. Drill 1⁄8″ pilot holes through the flange and into the pan. Screw the flange to the pan.
10. Thread the tail top piece into the tail through the drain flange. Use a speed square or other lever, such as spread-channel lock pliers, to snugly tighten the tail top piece in place.
11. Install tile underlayment for the rest of the project area. If the underlayment is higher than the top of the pan once it is installed, you’ll have to sand it to level, gradually tapering away from the pan.
12. Scrape any stickers or other blemishes off the pan with a putty knife. Lightly sand the entire surface of the pan using 120-grit sandpaper to help the sealant adhere. After you’re done sanding, wipe down the sanded pan with a damp sponge. Make sure the entire area is clean.
13. Seal the edge seams at the wall and between the pan and subfloor with waterproof latex sealant. Caulk any pan screw holes that were not used.
14. Cut strips of waterproofing tape to cover all seams in the tile underlayment (both walls and floor). Also, cut strips for the joints where walls and floor meet. Open the pail of liquid waterproofing membrane and mix the liquid thoroughly. Beginning at the top and working down, brush a bed of waterproofing liquid over the seams. Before it dries, set the tape firmly into the waterproofing. Press and smooth the tape. Then brush a layer of waterproofing compound over the tape
15. Trace a hole in the center of the waterproof drain gasket using the bottom of the drain clamping donut. Cut the hole out using scissors. Be careful cutting the gasket because it is a crucial part of the drain waterproofing. Check the fit with the gasket against the underside of the clamping donut top flange.
16. Apply a thin coat of the waterproofing compound around the drain hole and to the back of the drain gasket. Don’t apply too much; if the waterproofing is too thick under the gasket, it may not dry correctly.
17. Put the gasket in place and brush a coat of the waterproofing over the gasket. Screw the clamping donut in place on the top of the drain and over the membrane. Hand-tighten the bolts and then cover the clamping donut with the waterproofing compound (avoid covering the slide lock for the drain grate).
18. Use a roller to roll waterproofing compound across the walls and over the entire pan surface. The ideal is 4mm thick (about the thickness of a credit card). Allow this first coat to dry for 2 hours, then cover with a second coat. This should conclude the waterproofing phase of the project, and you’re ready to begin laying tile once the waterproofing compound has dried thoroughly.
How to Install Tile for a Curbless Shower
TOOLS & MATERIALS
- Ear and eye protection
- Work gloves
- Thinset tile adhesive
- Tile saw or nippers
1. Set the floor tile first. Begin by placing a sample of the floor tile directly next to the drain so you can set the drain grate height to match. The adjustable mounting plate for the grate should be flush with the tops of the tile.
2. Begin laying floor tile in the corner of the shower. Lay a bed of thin-set tile adhesive, using a notched trowel. The thinset container should specify the notch size (3⁄8″ square notch is common).
3. Place the corner tile into the bed of thin-set and press it to set it. Don’t press down too hard or you will displace too much of the material. Continue laying tile, fanning out from the corner toward the drain opening. Leave space around the drain opening as it is likely you’ll need to cut tiles to fit.
4. Install tile so a small square of the untiled area is left around the drain opening (which, in the system seen here, is square, making for an easier cutting job)
5. Mark the tiles that surround the drain opening for cutting. Leave a small gap between the tiles next to the drain-grate mounting plate.
6. Cut the tiles along the trim lines using a tile saw. If you are not comfortable using a tile saw, score the tiles and cut them with tile nippers.
7. Apply thin-set onto the shower pan, taking care not to get any on the drain-grate mounting plate. You may need to use a small trowel or a putty knife to get into small gaps.
8. Set the cut tiles around the drain opening, doing your best to maintain even gaps that match the gaps in the rest of the floor. Once you’ve finished tiling around the drain, finish setting floor tile in the rest of the project area.
9. Let the floor tile set overnight and then apply grout. Using a grout sponge, wipe the grout over the gaps so all gaps are filled evenly. After the grout dries, buff the floor with a towel to wipe up excess residue.
10. Snap the grate cover into the cover mounting plate (if you’ve stuffed a rag into the drain opening to keep debris out, be sure to remove it first). The grate cover seen here locks in with a small key that should be saved in case you need to remove the grate cover.
11. Begin setting the wall tile. Generally, it’s easiest if you start at the bottom and work upward. Instead of thinset adhesive, an adhesive mat is being used here. This relatively new product is designed for walls and is rated for waterproof applications. It is a good idea to use a spacer (¼” thick or so) to get an even border at the bottoms of the first tiles.
12. In the design used here, a border of the same mosaic tile used in the floor is installed all around the shower area to make the first course. Dark-brown accent tiles are installed in a single vertical column running upward, centered on the line formed by the shower faucet and showerhead. This vertical column is installed after the bottom border.
13. Next, another vertical column of accent tiles is installed on each side of the large, dark tiles. These columns are also laid using the floor tile, which connects the walls and floor visually in an effective way.
14. Finally, larger field tiles that match the floor tile used outside the shower area are installed up to the corner and outward from the shower area. Starting at the bottom, set a thin spacer on top of the border tiles to ensure even gaps.
15. Grout the gaps in the wall tiles. It’s usually a good idea to protect any fittings, such as the shower faucet handle escutcheon, with painter’s tape prior to grouting. If you wish, a clear surround may be installed to visually define the shower area, as in the photo to the right, but because the shower pan is pitched toward the drain it really is not necessary.