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Installing SMC Shower Niches and Soap Dishes

Updated September 2026

Installing an Ella SMC shower niche means recessing it between two studs, packing out the flanges so they sit flush with the plasterboard, screwing it to the framing without over-tightening, waterproofing it with a self-adhesive membrane and sealing compound, tiling over the flanges, and finishing with silicone that cures for 24 hours before the first shower. The SMC soap dishes are surface-mounted through two 5/32 inch holes and sealed the same way. This article covers both; wall kits, tiles and the accessory spec comparison are separate articles.

Niche Sizes

  • Single niche: 14 inches wide by 16 inches high by 3 1/2 inches deep.
  • Dual niche: 16 inches wide by 27 inches high by 3 1/2 inches deep, two compartments.
  • Triple niche: 16 inches wide by 39 inches high by 3 1/2 inches deep, three compartments.

All are molded from SMC with a 3/16 inch wall and a non-porous surface that resists mold and stains, with a flange around the opening. They are designed for solid shower walls and stud walls, and the recessed installation depth is 4 inches. The full size table for niches, soap dishes, seats and doors is in shower doors, seats, niches and accessories: sizes and capacities.

Back view of the SMC triple shower niche showing the mounting flange and three recessed boxes
The SMC triple niche from behind: the flange is what gets screwed to the framing and lapped by the tile.

Before You Start

Open the packaging carefully and never cut into it with a blade. Store the niche flat, not leaning against a wall, and keep it out of wet or humid conditions. Dry-fit and mark every location before cutting. Have a second person help mark and set the niche. Protect the shower tray and cover the drain so debris cannot enter. Use a spirit level throughout and apply silicone at every stated joint.

Installation Steps

  1. Determine the location. Center the niche between two studs. Note the thickness of the finished wall, because the flanges must end up flush with the plasterboard surface before tiling. Check for hidden pipes, cables and screws, then mark the recessed body on the wall, not the flange outline.
  2. Cut the cavity. Remove the niche, check again for hidden services, and cut the opening with a saw or angle grinder. Confirm you have the full 4 inch depth. Smooth the edges and clean up.
  3. Reinforce the cavity. Add horizontal noggins between the studs at the top and bottom of the niche so the framed opening matches the niche dimensions. Push the niche in gently and check the surface levels.
  4. Set the depth. Notch the existing plaster or pack behind the flanges with wooden strips (not supplied) so the flanges sit flush with the new plasterboard. For tile or wallboard finishes, space the flanges to match the finish thickness. Insert the niche and confirm the flanges are flush and level.
  5. Fasten. Drill evenly spaced pilot holes through the flanges into the framing and secure with countersunk screws (not supplied). Do not over-tighten; cracks caused by over-tightened screws are not covered by warranty. If the niche will not be covered by tile or wallboard, seal the whole flange perimeter to keep water out.
  6. Waterproof. With every surface clean and dust-free, apply the vertical self-adhesive membrane tape first, then the horizontal, so they overlap. Trim the excess.
  7. Seal. Embed the membrane in a thin, flat layer of flexible sealing compound over the flanges, following that product's instructions.
  8. Tile. Once the compound is dry, apply tile adhesive and tile the wall; the tiles can overlap the niche flanges.
  9. Finish. Run silicone around the niche edges. Allow 24 hours before showering.

Watch: Finishing the Wall Around a Niche

There is no niche-specific video yet, but this short clip shows the wall finish that most often laps over a niche flange: the grout-free tongue-and-groove tiles are measured, scored and snapped to size, glued on the back, given a thin bead of silicone at each joint, and snapped into place row by row. The cut around a niche opening is made the same way, and the article on installing wall kits, surrounds and tiles covers the acrylic panel cutouts, which need rounded corners to prevent stress cracks.

Soap Dishes

  • Rectangular soap dish: 11 inches wide by 2 inches high by 5 inches deep.
  • Corner soap dish: 8 inches wide by 2 inches high by 8 inches deep.

Both are SMC with the same waterproof, non-porous surface as the niches, and both spec drawings show two 5/32 inch diameter mounting holes. Mount them with fasteners suited to your wall and backing, drilled through a grout line where possible, and seal each hole and the edges with silicone so water cannot travel behind the dish. Matching silicone and additional accessories are available; ask your Ella dealer or the team at (800) 480-6850.

White SMC rectangular soap dish mounted on a subway tile shower wall
The rectangular SMC soap dish surface-mounted on a subway pattern wall, with silicone at every edge.

Care

Wipe after each use, clean weekly with a mild non-abrasive cleaner, avoid bleach, ammonia and acid-based products, and never use abrasive pads or sharp tools. Inspect the caulk regularly and replace the silicone every 12 to 18 months or sooner if it cracks or separates. Dry the niche to limit hard-water spots and keep the bathroom ventilated; if mold appears, clean it with a diluted vinegar solution and rinse. The same routine applies to the SMC bases, and it is collected in caring for Ella showers, bases, niches and seats.

Common Questions

How do I frame the opening?
Between two studs with noggins top and bottom so the rough opening matches the niche body. The full 4 inch depth must be clear, so check for pipes and cables before you cut.
Should the flange sit flush or proud of the wall?
Flush. The flanges should meet the plasterboard surface so tile or wallboard can lap over them; pack behind the flanges with wood strips if the wall is thicker than the flange depth.
Can the niche be surface mounted instead of recessed?
Yes, unfinished, as long as every gap around the flange is fully sealed against water getting behind it. Recessing is the standard method and gives the cleanest look.
Which niche sizes exist?
14 by 16, 16 by 27 and 16 by 39 inches, all 3 1/2 inches deep, in single, dual and triple compartment versions.
How is the soap dish attached?
Through its two 5/32 inch holes with fasteners suited to your wall, ideally drilled in a grout line, then siliconed at the holes and around the edges.
Can I put a niche in an acrylic panel wall or an SMC wall kit?
Yes. The niche is framed into the studs behind the wall, and the panel is cut out to the recessed body so it laps the flange. Cut acrylic openings with rounded corners and seal the cut edge with silicone.
How long before I can shower?
Allow 24 hours after the final silicone around the niche or soap dish so it cures fully.
What is the warranty on the niche?
Cracks from over-tightened screws are not covered, so drive the screws snug and no further. For the printed term on your niche, check the installation sheet that came with it or ask the team with your order details.
What cleaners are safe on SMC?
A mild non-abrasive bathroom cleaner. Avoid bleach, ammonia, acids and scouring pads; the list of approved and unsafe products in which cleaners are safe applies here too.

For anything specific to your model or wall build-up, open a ticket at ellasbubbles.com/support or call (800) 480-6850 and the team will walk your installer through it.

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