Sterling Vikrell Bath Shower Installation: a Step-By-tep Pro Guide
In the 2026 Show Village at the International Builders' Show, we installed a bath shower unit in a framed opening. Nick Balkum and Brian Campbell did the installation while Michael Anschel of AO Design + Build + Architecture and Dax from Sterling talked through the process.
Dax walks through a complete installation of a Sterling Vikrell alcove bath shower unit, covering everything from the Vikrell material itself — a compression-molded blend of resin, fiberglass, and crushed stone — to subfloor prep, tub leveling, J-clip anchoring, and caulk-free wall panel installation. Whether you're a plumber, remodeler, or general contractor, this video covers the techniques, tolerances, and product features you need to install a Sterling Vikrell unit correctly the first time, including ADA adaptability compliance, dry block water containment, and the tab-and-slot wall system that makes the Medley Smooth 6032 one of the fastest alcove installations on the market.
TRANSCRIPT:
My name is Dax, category manager for Sterling Vikrell. Today we're walking through an installation of a Sterling Vikrell bath shower unit.
Sterling is a brand within the Kohler company portfolio, focused on the pro market and commercial-grade solutions. Everything in the Sterling portfolio is designed to be easy to install, built to last, and backed by Kohler.
Vikrell is a proprietary material to the Kohler company — a compression-molded solution made of resin (the binding agent), fiberglass (for strength), and crushed stone, which makes up the majority of the material. Those components are heated to 350°F and compressed with over 1,800 tons of force. As it cures and hardens, Vikrell is born.
In my opinion, it's the most durable material in the bathing and showering space. It's color-molded throughout, so there are no layers to chip, crack, or peel — no surface finish, just naturally high gloss. Because of the stone content, it has manufactured stone-like properties: non-porous, scratch resistant, and stain resistant. Once it's installed, you can throw crayons, red hair dye, or purple primer at it.
Subfloor prep and the felt pad (1:44)
Vikrell bath and shower pans are designed to be installed direct to the subfloor. We provide a felt pad that you lay flat on the subfloor, making sure it contacts all of the molded-in feet on the bottom of the tub. Staple or tape it down to keep it in place during installation.
The reason for the felt pad: subfloors are resin-rich, and our product is also resin-rich. When those two surfaces contact each other and there's any movement, it can create noise. The felt pad acts as a noise isolation barrier. We're going to show you how to install this tub so it doesn't move — but we always include that extra layer of protection.
Lifting, positioning, and leveling the tub (2:59)
Now we lift and position the tub into the alcove. We framed this opening at 60 and 1/8 inches — that 1/8-inch give is ideal.
Once the tub is set, check that each foot is in contact with the felt pad and flooring. If a foot isn't making full contact and you're not setting it in mortar, you can shim it with a wood shim.
At this point, level the tub front-to-back and side-to-side. Make sure that bubble is centered between the lines.
J-clips and plastic isolation clips (3:42)
What differentiates our Vikrell products is our set of four to five metal J-clips. These clips anchor the tub — once it's level — into the stud pocket so there's no movement. The clip slides between the tub and the wood shims; the J-hook lifts and suspends the tub, and then you anchor it with a 1-inch to 1-1/4-inch truss-head screw through the stud.
Note that at no point is the tub in direct contact with the wood framing. There's either a metal clip or a plastic clip holding it — both suspending it and locking it down — so the tub never rubs against the wood.
We provide two metal clips for the front and two for the back to isolate the tub. At every stud not covered by a metal J-hook clip, we provide plastic isolation clips to prevent any contact between the tile flange of the bathtub and the wood stud framing.
Once level and anchored, this tub is not going anywhere.
Installing the Medley Smooth 6032 wall set (5:53)
Now we install the Medley Smooth 6032 wall set. You'll notice we mold in shelving for ample storage, and there are ribs on the back side of the walls to eliminate flex. We start by inserting the back wall panel.
There's a tab-and-slot system: we mold positive tabs on the wall sets, and matching slots on the base that either get covered by tile or serve as the receiving end for the walls. The wall set sits on our bases the same way every time — simple, easy, and error-proof, like Legos.
The units can be unpacked in the garage. One person can maneuver through a standard doorway, hallway, and up to a second story, snap it in, and go. For the back wall, that's all we need — no need to fasten it to the stud framing at this point.
Dry block seal and water containment (7:06)
On the in-walls, we have a factory-installed black gasket called a dry block seal. It ensures that any moisture that builds up on the horizontal threshold of the tub hits that positive reinforcement and gets redirected back into the basin.
ADA and age-in-place backer blocking (7:35)
Age-in-place and ADA compliance is important. Many of our walls are ADA compliant. You can order factory-installed backers — 1x6 wood blocking built into the walls — so grab bars can be added later. If you need to call an audible on the job site, we've also molded in the locations where you could add your own backers. For a traverse bath-shower, you'll still meet the ADA adaptability Title 24 requirement.
Center valve line and mixer alignment (8:09)
We've also molded in a center valve line on the back wall. The goal is to ensure your mixer valve and tub spout are always fully aligned with the overflow and drain — no more guessing left to right. Simply drill a hole through that center valve line, run a hole saw through it, and you'll get a consistent, level overflow and mixer valve placement every time.
All you need to do is measure the height of the mixer valve. Once you've drilled the hole, you're ready to install the in-walls.
Installing in-walls: gaps, tolerances, and fastening (8:49)
To install the in-walls, lift them about 2 inches above the back wall, engage the interlocking joints between the back wall and the in-wall, then gently slide them down. You'll engage the dry block seal, and the wall is perfectly installed.
Confirm the tab-and-slot is properly lined up — the in-walls and the bath should be fully flush. The seam gap tolerance: the first 6 inches in from the front should be no more than 1/32 of an inch (one credit card thickness). All other seams can be up to 3/32 of an inch, or about three credit cards max.
Run screws through the in-walls both vertically and horizontally. When you reach the back wall, make sure the seams between the in-wall and back wall are less than 3/32 of an inch. If the stud pocket isn't plumb, you can run a wood shim to correct it. Then finish drilling and anchoring to the stud framing.
Final result: caulk-free, glue-free installation (10:42)
The result is a fully caulk-free, no-adhesive installation. No glue of any kind. We mold in a water containment system within the vertical and horizontal seams that redirects any moisture back into the basin — a watertight seal using physics to keep it dry.
It's smart engineering. And because Vikrell is a durable sheet-molded compound with no layers to chip, crack, or peel, trades people can work around it confidently. Even drop a hammer in the tub — it's 100% okay.