One shelf
Useful when you need storage for only 1-2 users. Typically a few taller bottles on the lower level, and a soap, razor and/or narrow containers on the shelf.
Image 1 of 6: Redblock Rb3m 316L stainless steel shower niche shelf installed in a tiled 12-inch shower niche
Short answer and product facts
What Is the Redblock Rb3m Shower Niche Shelf?
The Redblock Rb3m Shower Niche Shelf is a 3 mm thick 316L stainless steel shelf that fits all prefab and custom tile-ready shower niches with a 12-inch-wide rough opening. It installs into the side-wall grout joints during tiling, creating a low-profile storage level 1/2" away from the tiled back-wall of the niche, so it doesn't interfere with your tile layout.
| Product fact | Current information |
|---|---|
| Product Type | A suspended, low profile stainless steel shelf for tiled shower niches |
| Primary Material | Marine grade 316L stainless steel |
| Installation Method | Inserts into 1/8" wide grout lines on the niche side walls during tile setting. |
| Waterproofing Impact | Installs in the tile assembly, clear of the niche waterproofing layer |
| Use Cases | New tile-ready, prefab, or custom shower niches that have a 12" wide rough opening before tiling |
| Approximate dimensions | 11 13⁄16" (300 mm) long × 2.6 in deep × 0.12 in thick |
| Weight Capacity | 11 lbs recommended maximum load based on Redblock's in-house load testing. |
Why This Product Exists
Finally, a thin, strong, functional, and modern shelf for shower niches
The Redblock shower niche shelf was designed by shower remodel pros, Steve Gehrmann and his brother Dave. Their intention was to create an attractive, low-profile, low maintenance, and multi-functional alternative to the niche shelf products currently available on the market.
Tiled shelves take up too much room, split up your niche, and require extra labor. Glass shelves don't drain, are super slippery, and impossible to keep clean. Most popular steel shelves are too thick for the grout line, are crudely finished, and interrupt the back-wall tile pattern.
The Redblock Rb3m is an easy install, side-wall-supported shelf that adds another storage level, provides drainage and hanging functions, and allows the niche’s back-wall tile to remain visually uninterrupted.
Features & Benefits
Engineered to eliminate the biggest shower niche shelf problems
316L stainless steel
More corrosion resistant than common 304 stainless steel, especially when exposed to chloride-based shower cleansers and hard water.
3mm body & install tab thickness
Strength and rigidity to support any shower or bath product you'll ever need to store on it.
Rear gap & side-wall support
An attractive "floating" aesthetic offers the benefits of all-around water drainage, easier cleaning, and uninterrupted back wall tile design.
CNC edges & corners
All edges, drainage holes and hanging openings are CNC machined and tapered for snag-free cleaning and a refined finish.
Reversible orientation
The shelf can be flipped so the logo faces down, and the long hanger slot can face the front or rear of the niche.
Principal Design Advantage
Supported from Both Niche Side Walls
The Redblock Rb3m Shower Niche shelf side-wall-supported design creates a low-profile storage level without requiring it to be built into, attached to, or visually interrupt the niche’s back-wall tile.
- Both shelf ends are supported at corresponding side-wall tile joints.
- The back-wall tile can continue visually behind the shelf.
- The 3 mm shelf body presents a subtle minimalist impression, while most other shelf options can feel obtrusive & bulky.
- Shelf position & spacing can be determined during tile layout planning, OR during tile installation if shower wall grout joint alignment isn't important.
Why 316L Stainless Steel Matters
Showers are hard on metal.
316L is a molybdenum-alloyed, low-carbon stainless steel with a much greater resistance to chlorine, and hard water corrosion, compared to regular 304 Grade SS. That's what makes 316L stainless steel perfect for showers.
| Material | Corrosion Resistance | Durability | Shower Suitability |
|---|---|---|---|
| 316L Stainless Steel | Excellent | High | Best long-term choice due to its high corrosion resistance, especially when exposed to corrosive chloride based cleaners and hard water. |
| 304 Stainless Steel | Good | High | Higher maintenance due to lower corrosion resistance, compared to 316L. |
| Aluminum | Moderate | Moderate | Lightweight, but scratches easily and requires electroplating for increased durability. |
| Plastic | Does not rust | Low | Temporary appearance and degrades over time (discoloration, cracking) when exposed to heat and cleaning products. |
Waterproofing Relationship
Installed over the waterproofing layer.
The shelf simply rests in a grout joint on the side walls of your niche, close to the waterproofing layer but never penetrating or interfering with it in any way.
For the broader shower assembly, see Redblock’s complete shower waterproofing guide.
Tile and Grout Joint Compatibility
Will It Fit Your Shower Niche?
The Redblock Rb3m Shower Niche Shelf is 11 13⁄16" (300 mm), so it fits all prefab and custom tile-ready shower niches with a 12-inch-wide rough opening.
Measure the unfinished niche opening from side wall to side wall before tile is installed, to ensure that it's 12-inches. Your niche side wall tiles must be cut to the approriate length with grout joints aligned, to ensure that the shelf is level and at the appropriate shelf height.
| Niche type or source | Opening size before tiling | Installation stage | Status | Installer notes |
|---|---|---|---|---|
| 12" Schluter Kerdi-Board-SN models | 12 × 12, 12 × 20, 12 × 28 | During tiling | Fits | Plan the opposing side-wall tile joint locations prior to tiling so shelves are level, and there's appropriate vertical distance above and between them. |
| 12" Wedi models | 12 × 12, 12 × 18, 12 × 26, 12 × 38 | During tiling | Fits | Plan the opposing side-wall tile joint locations prior to tiling so shelves are level, and there's appropriate vertical distance above and between them. |
| Generic 12" Prefab tile-ready niches | 12" wide rough opening | During tiling | Fits | Always confirm that the unfinished niche opening is 12" wide before purchasing, and plan the opposing side-wall grout joint locations prior to tiling. |
| Custom tile-ready niche | 12" wide rough opening | During tiling | Fits | Build a niche opening of 12" wide after waterproofing, and plan the opposing side-wall grout joint locations prior to tiling. |
| Completed natural-stone tiled niche without perimeter trim | Approx. 11" finished width after tiling | After tiling | Limited exception | Retrofit may be possible if opposing grout joints align, grout joint width is ⅛" (or larger), and no additional edge treatments block insertion from the front. |
| Completed tiled niche with perimeter tile trim | Approx. 11" finished width after tiling | After tiling | Unsuitable for retrofit | Trim commonly blocks front insertion, and opposing accessible grout joints may not align. |
Grout-Joint Compatibility
A standard 1/8-inch grout joint width is the standard installation condition for the 3 mm shelf however, it can also be installed into a 1/16-inch grout joint if the joint is widened slightly at the shelf install leg locations. Redblock’s installation video demonstrates this method and the tile-edge preparation required.
| Joint condition | Expected fit | Installer considerations |
|---|---|---|
| Standard 1/8-inch wide grout joint | Intended installation condition | Dry fit the shelf and follow the official installation instructions. |
| Grout joint slightly narrower than 1/8 inch | Minor adjustment may be required | Evaluate the tile edges and available shelf clearance before setting the tile. If adjustment is required, be careful not to chip the tile face. Do not force the shelf into the joint. |
| Tile layout with 1/16-inch grout joint width | Tile adjustment required | Trim the tile above the shelf at the install tab locations prior to tile installation, to provide clearance for the 3mm tabs. When adjusting the upper tile, be very careful not to chip the tile face. Follow Redblock’s approved installation method. |
| 1/8-inch grout joint in an existing niche | Normally unsuitable | Retrofit may be possible if the original rough niche opening (before tile) is a full 12", opposing grout joints align, grout joint width is ⅛" (or larger), and nothing blocks shelf insertion from the front. |
Installing the Shelf with 1/16-Inch Grout Joints
This video demonstrates how the tile above the shelf needs to be adjusted to allow enough room for the SNS installation tabs.
Retrofit limitations
Perimeter trim usually prevents the shelf from sliding into a niche from the front, even if the niche has the correct opening width, the grout joints are 1/8" wide, and the grout joints align on each side of the niche. Natural-stone tile with polished edges (no tile trim) may allow this type of installation if the above criteria are met however, this method may involve other risks that are difficult to anticipate such as tile chipping.
Shower Niche Shelf Planning Tool
Your Best Niche Shelf Plan.
Answer five project-planning questions to check the required niche opening, installation stage, grout-joint width, perimeter-trim material and orientation, and likely shelf quantity.
Shelf Layout
Use your favorite shower products to determine the correct height between shelves.
The shelf planning guidance below will help you determine your ideal shelf heights. There's also some installation example images to help you visualise one, two, and multi-shelf arrangements.
- Before you cut your side wall tiles, gather together the products you'll realistically be storing in the niche.
- Practice arranging these products in the niche to get a feel for where you want everything to rest after the niche is complete and in-use. This will give you the best idea of your ideal shelf heights.
- Mark those shelf heights on the niche side wall and cut your side-wall tiles (or get your contractor to do it).
- Dry fit the side wall tiles, and the shelves in the niche to confirm your shelf placement decision, and to confirm that the shelves are level.
Two shelves
Creates three storage levels in a slightly taller niche (~24" interior height). Enough room for an assortment of shower items for 2-4 shower users. Larger bottle on lower level; middle & top shelf for smaller bottles, soaps, razors, tubs & creams.
Multiple shelves
More shelves means almost unlimited storage depending on your niche height. Be sure to choose smaller shower wall tiles if you want to make it easy to align niche shelves with the grout lines of surrounding shower wall tile.
Multi-Shelf Savings
More Niche Storage Levels. Automatic Savings.
Mix and match eligible Redblock shelf products and receive an automatic retail discount when you purchase two or more.
No discount code required. Available to retail customers & all new trade and business accounts.
Buy 2 shelves
Save 10%
Choose two eligible shelves for a tall niche, multiple showers, or a mixed storage layout.
Buy 3 or more
Save 15%
The 15% discount applies to all eligible shelves in the qualifying retail order.
Popular combinations:
- Two shelves creating three storage levels in a tall shower niche.
- Niche shelves combined with Redblock corner shelves in the same shower.
- Shelf products purchased for multiple bathrooms or client projects.
Everyday performance
Strength for Everyday Shower Storage
A 3 mm stainless-steel body combined with 3mm install tabs, and support from the niche side walls provides the support you'll need for all your shower and bath products/ accessories.
Recommended maximum load
Redblock recommends a maximum load of 11 lbs on the Rb3m shower niche shelf based on in-house load testing. This recommendation has not been independently tested or certified.
Redblock vs Other Niche Shelf Options
Compare Construction, Installation, and Daily-Use Trade-Offs
Different niche-shelf materials and construction methods solve the shower storage problem in different ways. This comparison focuses on shelf materials, construction, support, drainage, cleaning, damage risk, and installation work.
| Characteristic | Redblock 316L SS shelf | Generic 304 Stainless shelf | Tempered glass | Stone shelf | Tiled shelf |
|---|---|---|---|---|---|
| Profile | 3 mm low-profile plate | Depends on product | Minimum 10mm (about ⅜") - visually light | 20 or 30 mm (about ¾" & 1 ¼") | At least 2", effectively splitting the niche into two separate niches |
| Corrosion-resistance margin | One of the most corrosion resistant steel alloys available | Moderate; depends on finish, care/cleaning, and install conditions | Not a metal-corrosion issue | Acid corrosion (etching) by acidic & chloride-based cleansers can dull and stain the finish | Acid corrosion by bleach-based & acidic cleansers can weaken & dissolve tile grout |
| Drainage | Integrated slots | Depends on product | Usually none | Depends on slope and/or fabrication | Depends on slope created during framing or tiling |
| Accessory hangers | Integrated long slot & loofah notch | Usually none | Usually none | Usually none | Usually none |
| Back-wall tile continuity | Gap behind shelf means tile is uninterrupted | Shelf usually interrupts the back-wall tile | Shelf usually interrupts the back-wall tile | Shelf usually interrupts the back-wall tile | Shelf usually interrupts the back-wall tile |
| Installation labor | Placement into side-wall grout joints during tiling | Requires 5⁄32" (4mm) notch into side AND back-wall tile layer | Requires 3⁄8" install notch into side AND back-wall tile layer | Requires 3⁄4" install notch into side AND back-wall tile layer | Prefab shelf install and tile setting - Highest labor cost |
| Ease of Cleaning | Open on all sides, rounded corners, low-profile, smooth surface | Closed along the back and side walls, sharp laser cut edges & perforations. | Closed along the back and side walls but very smooth surface | Closed along the back and side walls, smooth surface but requires sealing | Closed along the back and side walls, multiple grout lines, and trim ridges |
| Damage risk | Zero fracture risk, low corrosion risk, moderate scratch risk | Zero fracture risk, moderate corrosion risk, moderate scratch risk | High fracture risk, zero corrosion risk, low scratch risk | Moderate fracture risk, moderate etching risk, moderate scratch risk | Low fracture risk, high grout etching risk, low scratch risk |
| Retrofit suitability | Normally limited | Difficult | Very difficult | Very difficult | Practically impossible |
Early-Stage Shower Storage Planning
Choose the Right Storage Approach
If you're still not sure what type of storage is the best for your shower, compare the three Redblock shower storage options below.
Tiled niche with Redblock niche shelves
Best when you're installing a tiled, recessed shower niche as your preferred shower storage, and you want one or more slim storage levels inside it.
Requires a 12-inch-wide opening measured before tile and coordinated opposing side-wall joints.
Complete Redblock stainless steel niche
Best when the project is still at the framing stage and you want an integrated, recessed, brushed, 316L Stainless Steel storage niche rather than a niche finished with tile.
It's installed during a full shower remodel only (no retrofit). By far, the easiest, most waterproof, and most vapor-proof recessed shower storage option available.
Redblock corner shower shelves
Best when you need a fast and easy retrofit storage option for your tiled shower, or if you prefer corner storage, over recessed storage in your new shower build.
The Redblock corner shelf stays "out of your way" in the shower, due to its in-grout corner installation, and can be installed into new showers, or retrofit into existing showers.
Installation Overview
Flexible Installation Timing
Unless you're planning to line up the grout lines on the shower wall with those on the niche side walls, niche shelf installation can happen anytime; before, during, or after the surrounding shower-wall tiling.
Installation sequence
- Confirm that the unfinished niche opening is 12 inches wide, then confirm perimeter tile trim type and placement.
- Complete the niche back wall tiling.
- If trim anchor leg is parallel to shower wall, complete shower wall tile and perimeter trim install, positioning the trim to allow adequate depth for niche side wall tiles.
- Confirm the intended position of shelves inside the niche, then cut the side wall tiles to the correct sizes, ensuring that each side wall tile has the same vertical size, so that opposing horizontal joints align horizontally at the shelf location.
- If the trim is oriented such that the anchor leg is parallel to niche side wall, you must install the niche side wall tiles, shelves, and trim before the shower wall tile. With this trim orientation, you must also ensure that the shelf install tab does NOT come into contact with the trim anchor leg if its metal (no concern if it's plastic)
- With larger format shower wall tiles, the shelf placement decision need not be made until the entire shower wall tiling is complete, since there's usually no concern about aligning the niche side wall tiles with those of the surrounding shower wall.
- However, if surrounding wall tiles are smaller dimension (subway or mosaics, for example), you may decide that aligning your niche shelves with the surrounding grout joints is important. If so, you must make your shelf placement decisions during the tile layout planning stage, well before tiling begins.
- Complete grouting, cleaning, and cure time using compatible materials and manufacturer instructions.
This overview is not a substitute for the official installation instructions.
Project materials and tools
Redblock supplies the shower niche shelf only. The prefab or custom niche, tile, perimeter trim, thinset mortar, grout, waterproofing materials, sealants, spacers, installation tools, and personal-protection equipment are usually supplied by your contractor.
See it installed
Watch the Redblock Shower Niche Shelf installation process.
Installation guide
Download the complete, step-by-step, Rb3m Shower Niche Shelf graphical install guide.
Download the PDF
Customer feedback
Easy to install, beautifully finished, and built solid.
Customers highlight the same practical advantages: straightforward installation, time saved during tile work, sturdy construction, and a clean finished appearance inside the shower niche.
Easy installation
Time-saving
Very sturdy
Clean design
★★★★★
“Simple yet a very functional design. Better than Kerdi niche shelves.”
★★★★★
“Saved us hours cutting tile; looks really nice. Install was a breeze.”
★★★★★
“Absolutely amazing product. Great quality and very sturdy. Fantastic service.”
For professional installations
Built for Remodel Professionals
The strongest value for a professional is a product that installs quickly, is durable enough to prevent callbacks, and also satisfies the client.
- Built for 12" prefabs: 3 mm thickness fits all 1⁄8" grout lines, 11 13⁄16" (300mm) length means compatibility with any 12" wide niche opening, custom or prefab.
- Reduced fabrication: Tiled shelves need to be built and tiled, while single-material shelves imbed into the back wall tile layer which means lots of custom tile cuts and extra labor. The Rb3m Shower Niche Shelf rests in the side wall grout joints, clear of the back wall tile, meaning faster installs & easier finishing.
- Repeatable detailing: useful for recurring 12" prefab and custom niche layouts. Predictable and repeatable.
- Project support: installation video, simple graphical PDF install guide, and direct contact with Steve at Redblock for any questions you may have.
- Professional purchasing: trade-pricing is available for all industry professionals. Just contact us.
Installer and product data
Product details for builders, remodelers, and specifiers
| Specification | Value |
|---|---|
| Product name | Redblock Shower Niche Shelf |
| Product Group ID | SNS12WC |
| Product SKU | SNS12WC-BM |
| Material | 316L stainless steel |
| Finish options | Brushed; Chrome PVD currently unavailable |
| Overall length | 11 13⁄16" (300mm) |
| Overall depth | 2.6 in |
| Thickness | 3 mm / approximately 0.12 in |
| Approximate net weight | 0.6 lb |
| Weight Capacity | 11 lbs based on Redblock's in-house load testing. |
| Installation Method | Inserted into the two opposite niche side wall grout joints |
| Intended Grout Joint | Ideally 1/8" |
| Downloads | Download Niche Shelf Spec Sheet |
Shipping & Returns
Fast shipping and a straightforward return policy.
Shipping Information
- ✓Free shipping within the Continental US.
- ✓Ships in 1-2 business day under normal conditions.
- ✓Standard delivery typically 4–7 business days after tracking is received.
- ✓Durable packaging designed for safe delivery.
Return Policy
- ✓30-day return policy for eligible returns.
- ✓Free returns on defective items and eligible returns.
- ✓Full refund or exchange when eligible.
- ✓Contact us with questions about return eligibility.
Package Contents
One Redblock shower niche shelf. Tools, silicone, and pictured shower accessories are not included. Please see our Installation Instructions PDF, and/or our Installation Video for detailed installation guidance (located in INSTALLER & PRODUCT DATA, and SEE IT INSTALLED sections above).
Frequently Asked Questions
What contractors & homeowners ask before choosing a niche shelf.
Which shower niches does the Redblock Shower Niche Shelf fit?
It fits all prefab and custom tile-ready shower niches with a 12-inch-wide opening, measured before tile is installed (rough opening width).
How do I measure the niche opening?
Measure the inside of the unfinished tile-ready niche, horizontally from one side wall to the other side wall, before tile is installed. The opening must be 12 inches wide to fit the Rb3m niche shelf.
When should the Rb3m shower niche shelf be installed?
The Rb3m SNS is normally installed during tile installation. The two niche side-wall tile joints must be planned at the same elevation, and the shelf should be fitted before the niche side-wall tile work is completed and grouted.
Can the shelf be installed in an existing, finished, tiled niche?
Normally, no. Perimeter tile trim frequently blocks insertion, and opposing grout joints may not align. A retrofit may be possible in an uncommon trim-free niche, where polished natural-stone tile has been installed, side-wall grout joints align to level, and grout joints can be safely cleared to slide the shelf in from the front.
What grout-joint width is required?
The shelf is designed around a standard 1/8-inch grout joint. Slightly narrower joints may require tile-edge adjustment by an experienced installer. A 1/16-inch joint should not be treated as a guaranteed direct fit.
Can the Redblock Shower Niche Shelf be flipped so the logo faces down?
Yes. The shelf can be flipped so the logo faces downward. The long washcloth or bathing-puff slot can also face toward the front or rear since both faces and all edges are identically finished.
Why does Redblock use 316L stainless steel?
316L is a molybdenum-alloyed, low-carbon stainless grade which offers a higher corrosion resistance margin than 304 stainless steel against chloride-related and hard water corrosion.
Does the shelf affect the niche waterproofing?
No. The shelf is installed on the tile side of waterproofing membrane and rests on the tile edge for support, so there is no interaction between the shelf and the waterproofing layer.
What is the best material for a shower niche shelf?
Thin & minimalist shelf options such as stainless steel and glass are the most popular. Stainless steel is great for a niche shelf because it's thin (3-4mm), corrosion resistant, and very rigid. Glass is also very popular because it's relatively thin and transparent, but can shatter if struck, and is difficult to keep clean.
How deep should a shower niche shelf be?
Most niche shelves end up at a full 3.5" deep because they're designed to be imbedded into the back wall for stability. The problem is, this installation causes the very problems that homeowners complain the most about--soap scum and mold buildup in the back corners, and poor drainage.
Are shower niche shelves better than building a tiled shelf into the niche?
These days, "building" a shelf into a 12" wide niche is as easy as purchasing a prefab foam shelf from a supplier, and glueing it in. The part that many installers and homeowners dislike is the extra time & cost for the shelf tiling, the bulky size of the finished tiled shelf, and the hard-to-clean grout lines and corners inherent in a tiled shelf.
How many shelves should a shower niche have?
It depends on the vertical interior height of your custom or prefab niche, but there are no hard-and-fast rules for this. Your first job is to figure out exactly what you will be storing in your shower niche. Only then can you decide how tall your shower niche should be, how many shelves you want, and the vertical distance between them.
Low-profile storage, planned correctly
Better Design & Better Material for a Better Niche Shelf
Choose the Redblock Rb3m for 3mm 316L stainless steel construction, practical drainage and hanging details, and side-wall installation designed for tiled shower niches.