A Contractor’s Solution to the Challenges of Tile Edge Trim

by | Last updated Jul 1, 2018 | Bathroom remodel, Shower Niche

Master the challenges of tile edge trim with this helpful info and install tips

Tile Edge Trim - Section-of-Tile-Edge-Trim-Wheel-from-Iphone-250W-70

Summary of the topics covered in this post:

Installing floor tile, wall tile and tile edge trim pieces in the bathroom, can be a frustrating and difficult process even for the seasoned professional. That is why a good strategic plan is always important before you start any tiling job, no matter how small. With your mortar quickly drying, things can easily go sideways if your tile installation plan doesn’t cover all reasonable contingencies. In other words, you need to have all your ducks in a row beforehand. Part of that preparation needs to include understanding of the ins and outs of tile edge trim and some installation strategies. Future articles will cover some more tiling strategy hints but for now, it’s all about tile edge trim. I, Steve Gehrmann, a contractor with SKG Renovations, will be your guide into this topic. I hope you enjoy my post.

Product Types

There are four main types of tile edge trim that can be used to finish the perimeter of your tiling installations. These include stone trims, porcelain or ceramic trim tiles, as well as plastic and metal trims. These come in various configurations depending on the product and their use, but the metal tile edge trims and stone trims are the most popular.

Stone Trims

Using real stone or engineered stone to cap a shower pony wall or to frame the inside of a tiled shower niche is gaining in popularity. Although this is not technically a tile trim, the stone material is quite thick so it offers the opportunity to create a finished trim by polishing the outside facing edge. This strategy is getting more popular because it creates a very compelling seamless look and is easier to install. These kind of installations can produce a beautiful result, but they can be a fair bit more expensive than a standard tile edge trim. They also require very accurate measurements and a good stone fabricator to cut the pieces and polish the edges.

Ceramic & porcelain trim tiles

Ceramic or porcelain trim tiles can have a finished square edge, or more commonly a larger radius “bull-nose” edge. These types of trims were common in modern designs during the 1980’s and early 90’s but are no longer popular in todays modern bathroom designs. There are some unique modern trim tiles available today, but they are usually special order items and generally quite expensive. In contrast, it is quite common to see these tiles in more traditional design schemes these days. The attached image shows a ceramic trim tile being used very nicely around a tiled shower niche in a traditional bathroom design.

Metal and plastic tile edge trims

Metal and plastic tile edge trims come in several profile shapes and colors, but plastic is the least popular of this group because they do not stand up well to abrasion. The metal trims are by-far the most common tile edge trims used in most mid cost and higher end renovations (image of sample trim wheel). They are ideal for high abrasion areas such as floors, but have also become a standard in most shower wall tiling installations. They are available in the widest range of  finishes and profile styles, but the very narrow top edge profile is the most popular. In addition to the attached image, you can find a large selection of profiles on the Schluter Systems website.

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If you’ve decided to install a metal tile edge trim, and you’ve picked the type and style you want, then it’s time to choose the finish. You should be prepared to select your trim finish well in advance of your tiling project because some finishes are special order items. You should also be prepared for a wide variation in price. Some of the less popular finishes can easily be twice (or more) the cost of a more common finish. The general rule when picking a tile edge trim finish is to try your best to match the trim with your bathroom fixture finishes, although there are some exceptions. Generally, tile edge trim should be an attractive compliment to your bathroom design, but not a stand-out feature.


It is not always obvious what depth you should select for your metal tile edge trim, even when you have your tile and trim in hand at the home improvement store. It is a good strategy to err on the plus side for your trim depth to avoid the terror when you see the tile edge protruding above the trim during installation. To choose a trim depth that is 1/16” deeper than your tile is very standard among professionals in the industry, but it is minimal for the DIY’er. You must keep in mind that only the thin finished part of the trim will be exposed at the edge of your tile work. Because this bonding portion of the trim sits beneath the tile (the cross hatched flange seen in the image), you should allow enough mortar beneath the tile to allow the tile to bond to the trim, and the trim to bond to the tile backer board. Pushing against the tile with great force to try to get it to match the trim depth only means that you picked a trim depth that is a bit too shallow. Squeezing all the mortar out between your tile and trim mounting flange also reduces bond strength significantly. It is much safer to go with a trim that’s about 1/8” deeper than the tile thickness, especially with porcelain tiles that have a very square (rectified) edge. There is very little room for error with this type of tile. If you don’t install tile routinely, you will likely be surprised at how much a thin layer of mortar between the tile and the trim mounting flange, will cause the tile to protrude.

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Trim Depth Example

The example image shows two different tiles installed with a 1/2″ trim. The darker tile is porcelain with a thickness of almost 3/8″ and the surrounding tile is ceramic with a 1/4″ thickness. The ceramic has lots of room beneath, requiring 1/8″ thick layer of buildup material beneath to allow it to match the porcelain tile and trim. However, the trim is a perfect depth for the porcelain tile. This 3/8″ tile requires an extra 1/8″ of depth for trim & tile to match evenly, due to the extra thickness added by the waterproofing membrane, and an allowance for some mortar beneath.


Another thing to be aware of when installing only ceramic tile is that many people have the tendency to choose their tile edge trim depth based on the thinner outside edge of the ceramic tiles they are using. This will get you into trouble when you have to match the thicker cut edge against the trim in a staggered tile layout. If you are installing a waterproofing membrane after you secure your tile edge trim in place, you must also remember to accommodate the membrane thickness in your choice of trim depth. Remember that you can always add a little extra mortar to raise the tile to meet the trim depth, but you are totally stuffed if you choose a trim depth that is too shallow.


When it comes to shower tiling, you may never need to worry about outside corners for your tile work unless you are installing a tiled shower niche or tiling a pony wall or shower bench. The most common occurrence of these corners is on the outer perimeter of your tiled shower niche. These days it is most common to use a metal tile edge trim, but with a higher cost, you also have the option of installing stone, and leaving the edge finishing to your stone fabricator. Just keep in mind that they are expensive and require a skilled stone fabricator to cut & polish them.

If you choose a metal tile edge trim, it must be installed with skill and precision. This trim piece is usually quite visible and you don’t want someone’s shoddy work to be on display in your new shower remodel. Firstly, if you want this installation to go smoothly, you should follow the strategies I have covered in the sections above. The challenging part will be matching the four corners evenly, with no gaps. You have two choices: to meet the two pieces of trim in the four corners with a square joint, or a miter joint (45 degree joint). The first option is clearly the easiest and offers the highest chance of success (see image), but it does not look as professional as a perfect miter joint. Another important condition is that you can only achieve a decent square joint when the top of the trim is flat. This can be achieved quite satisfactorily with Schluter Shiene or Jolly. With other more complex profiles, a miter joint will be required. If you decide on miter joints for your shower niche outside trim, it’s always safest to get a skilled and experienced tiling professional to do this work.

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A New Alternative

If you want another alternative to the outside corner installation problem around your shower niche, you can always install a finished shower niche with a built in tile edge trim. The only shower niche product that includes an actual built in tile edge trim is the one pictured here (by Redblock Industries). This product not only eliminates the difficulty of installing tile edge trim around your new shower niche, it also eliminates the construction of the niche entirely. It easily mounts into a square hole cut into your tile backer board during shower construction (two supports are installed before tile backer installation). After the waterproofing membrane is installed, your shower wall tile is installed right up to the shower niche tile edge trim, exactly the same as you would with any standard tile trim.


Inside corners are a common part of bathroom tiling installations, especially in the shower. There are some challenges to these corners and some elegant products and strategies available to meet these challenges. There are also some very useful and interesting tile edge trims that are not routinely used in modern bathrooms and showers but are also worth considering.



If you are like most tiling contractors, you will have some issues with finishing inside corners on wall tile installations. When wall tiles meet at a corner, you have a choice of tiling right up against the adjacent tile and rely on a white silicon bead to seal the corner (see image). Or you can cut the tile to create a grout line on one of the two walls. The former strategy is the most common mostly because it is simply the easiest of the two. A grout line in the corner tends to interrupt the visual flow of tile from one wall to the other, and is not generally considered to be a good look. Although these are the most common strategies, there are some interesting and professional looking alternatives to both these strategies.

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The inside corner tile edge trim (also called a cove trim) provides a professional finished look to any tile installation. The benefits of this trim are an attractive metallic finish compared with the standard grout or silicon corner. It also has a smooth radius making it easier to clean and provides two grout lines, allowing the corner to be completely sealed. A baseboard trim is also available for installation outside of the shower if your floor & wall tile meet. It has a very thin top profile and various bold metallic finishes, great for minimalist designs. There are also some very nice tile edge border profile trims designed to be mounted within a section of wall tile to create a separation between two different tiles, or simply as a bold interruption in the your wall tile design. There is even a wall profile trim with a shallow track down the middle for mounting a strip of 1″x1″ mosaic tiles.

I hope that this article has provided you with some confidence (even mastery) in the area of tile edge trim. I have attempted to shown you a range of the most popular and interesting tile edge trims, along with a few useful hints to help you with installation. Here is a summary of the topics covered:

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