Skip to content
  • by

How to Install a Corner Shelf in an Already Tiled Shower

by Steve

Redblock Shower Build, How-to logo

Hello again. This is Steve from SKG Renovations with another Redblock budget bathroom remodel post.

In this post, I’ll provide step by step instructions on how to install a shower shelf on an already tiled wall. Specifically, the rb3 Stainless Steel Corner Shower Shelf (see image below video).

This shelf is made from super corrosion resistant, Marine Grade 316 stainless steel, and has plenty of slots for water draining. This is also the only in grout corner tile shower shelf that can be installed into non-square shower corners.

This one is super easy. No demo and no special skills or tools required… just a quick, budget shower improvement idea for a bunch more storage, and a cool new look.

Installation Video

I would recommend that you also check out the install steps below the video. These steps include a bunch more info that will enhance & clarify the install steps.


The Redblock rb3 corner shelf is designed to be installed into an existing tiled shower wall, by removing a bit of grout at the install tab locations. That’s why it’s referred to as an in grout corner tile shower shelf.

But it can also be installed into a newly tiled shower by installing spacers into the install tab locations before grouting. After grouting, you simply remove the spacers, and insert the shelf tabs into the notches you’ve created in the grout line.

You should also keep in mind that this shelf is 3mm thick, so it’s designed to fit into 1/8″ (or larger) grout lines.

If your grout lines are 1/16″ wide, it’s still possible to install the shelf, but the grout line space needs to be widened out a bit. This means that a bit of tile will need to be removed from above the install leg location (in addition to the grout), to allow the shelf to fit into the grout line.

This should be quite easy to accomplish if the tiles are ceramic because they can be ground away with a sanding wheel (on a Dremel tool) to make them 1/8″ wide.

Step 1 – Determine Height

You first need to decide how high you want your shelf to be from the shower floor or tub edge.

If you’re planning to install it on the wettest side of the shower (valve and shower head side), I usually recommend to my clients that it should be installed around chest height (around 48″).

This is based on a common preference to keep the shelves out of the primary “splash zone”. This way they don’t get too drenched during showering but are still within easy reach.

If you want to install two corner shower shelves, 48″ is also a pretty good height to start, but you may want to start a little lower if you’re planning to install three shelves, or the top one may get a bit too high to reach.

Of course if your planning to install on the opposite side of your shower (outside the splash zone), your lowest shelf can be lower… any height you want really.

If you want to install more than one shelf, you should consider what you’re planning to store on your shelves to determine the distance between them. I generally install them 10″- 14″ apart, depending on tile size (distance between grout lines), and the homeowner’s preference.

Step 2 Mark Out Install Location

The shelf has two 2″ install tabs that insert into the grout line space, so you will need to mark these out on the grout line to determine where the grout should be removed.

This shelf is very well suited to installation into shower corners that are not square, but the install location will obviously vary slightly if the wall isn’t perfectly square.

As such, you should check your shower corner with a framing square before you mark out your install leg locations.

If the shower corner is more than 90 degrees, the install leg positions will be slightly closer to the corner. If the corner is less than 90 degrees, the install leg locations will be slightly further away from the corner.

In my experience, even if the corner is super wonky, the most I’ve ever had to adjust the install location is 1/16″ one way or the other.

Assuming the shower corner is 90 degrees, the location of the grout cutout locations are:

Left installation leg: 4″ – 6″ from the corner.

Right installation leg: 2 11/16″ – 4 11/16″ from the corner.

Step 3 Grout Removal

Because this the rb3 corner shelf is an in grout corner tile shower shelf, it requires that a bit of grout be removed in the two install tab locations.

As you can see in the video, the first grout removal step is to drill some pilot holes to 1/4″ depth.

At least four or five pilot holes in the grout is a good idea. The more pilot holes, the easier it will be to remove the rest of the grout.

Be very careful not to drill deeper than 1/4″ because you may unintentionally drill through the waterproofing membrane.

If you follow this pre-drilling strategy, you can easily remove the rest of the grout with a simple and inexpensive grout removal tool. You can buy this hand tool online or at any home improvement warehouse to remove the rest of the grout quickly and efficiently.

You can also use an oscillating saw (multi-saw) or a Dremel (or equivalent) to remove the grout. Both of these methods are pretty darn fast at removing grout, but I wouldn’t recommend using them unless you’ve had some experience with this kind of tool.

Step 4 Clean Notches & Dry Fit

After grout removal, be sure to clean out the install notches thoroughly. I generally use my shop vac to make sure there is no debris left, and to keep any dust out of the air.

It’s also a good idea to look into the notches to make sure they are clear of debris. If it’s clear, you should do a quick “dry fit” so you can see it slide into each of the notches.

Always insert the right install leg first and ensure it sinks into the notch at least 1/4″. You can also draw a pencil mark on the install leg, or apply a strip of masking tape at the 1/4″ depth mark, to ensure that the shelf is seated properly into the notch.

There is an angle cut out of the leading edge of the left install leg, so it can easily swing into place after the right leg is placed. You’ll know that the left leg is seated properly when the angled section disappears just below the surface.

If the shelf inserts properly into both notches, remove it again temporarily so you can do a final cleaning, and apply the silicon.

It’s also a good idea to wipe any dust off the tile face above and below the install notches. This will ensure the silicon adheres well to the tile above and below the shelf.

Step 5 Apply Silicon, Install Shelf

After the final cleaning, it’s now time to apply silicon into the install notches. This will help the corner shelf stay firmly in place between the existing tile.

Be sure to apply a liberal, uninterrupted bead of silicon into both notches. Don’t be too worried about how much you apply here. The excess will squeeze out when the shelf is inserted into the grout line space.

Now simply insert the shelf legs into the install notches, the same as you did during the dry fit.

All you need to do now is clean up the silicon that squeezed out when you set your shelf in place. You can do this with a silicon caulking tool or your finger, if you feel comfortable with this (like I do).

I usually apply a very small bead of silicon around the shelf install legs after I complete this step but you don’t need to do this if you feel that enough silicon squeezed out above and below the install legs during installation. The point here is to ensure that only a tiny amount of silicon surrounds the install legs.

If you’ve created a bit of a mess during silicon application you can use denatured alcohol, or 90% (or higher) rubbing alcohol to remove the silicon residue. It does a very good job removing silicon so be careful not to disturb the finished bead around the shelf legs while the silicon is still wet.

Congratulations!!… Your Redblock rb3 Corner Shower Shelf is Installed!

If you’d like any additional info on installing this shelf into an already tile wall OR into a newly tiled shower wall, please visit our rb3 Corner Shelf Install Guide.

Wrap Up

I hope I’ve demonstrated how easy it is to add more storage to your existing shower, by installing a cool new in grout corner tile shower shelf into an already tiled wall.

It installs quickly and easily into most existing tiled shower walls, and looks like it’s always been there… a beautiful, strong & permanent corner shower shelf solution!

Please leave a comment below if you have any questions!

Leave a Reply

Your email address will not be published. Required fields are marked *

Click the Ad link below to leave the Redblock site and continue to

Muf Tile Grout Saw - Grout Removal Tool

Click the Ad link below to leave the Redblock site and continue to Amazon.comMilwaukee Oscillating (multi) Saw

Click the Ad link below to leave the Redblock site and continue to

Saker Silicone Caulking Tools