Mitered tile corners are a clean way to finish an outside corner without a visible metal trim piece. The two tiles meet at a 45-degree bevel on each edge, and when they come together they form a clean 90-degree corner. Getting them right requires more than just cutting the angle.
Why Miter Instead of Using Trim
Metal or PVC trim profiles are a reliable way to finish outside corners, and we use Schluter profiles on many projects. Mitered corners make sense when you want the tile to be the only visible material at the corner, which is common on natural stone showers and high-end porcelain wall tile. A mitered corner also eliminates the visual interruption that a trim piece creates in a seamless tile pattern.
The Right Blade and Angle
Mitering tile requires a wet saw with a blade rated for the material you are cutting. For porcelain, use a continuous-rim diamond blade. For natural stone, use a blade appropriate for the hardness of the stone. Set the table to 45 degrees. Take the cut slowly. Rushing a miter cut on porcelain can chip the edge.
Test your angle with two scrap pieces before cutting your final tiles. Hold them together and check the corner visually. The joint should close cleanly with no gap at the face and no material peeking out at the back.
The Step Most People Skip: Epoxy the Corner
Before grouting, epoxy the mitered corner. Apply a tile epoxy adhesive to both faces of the miter, press the tiles together at the corner, and let it cure. This bonds the two tile edges together and gives the corner mechanical strength that grout alone cannot provide.
Without epoxy, the miter joint relies entirely on grout for structural integrity. Grout is not an adhesive. It will crack under normal movement and thermal cycling, and the corner will open up over time. Epoxy eliminates that failure mode.
Grouting After Epoxy
Once the epoxy has cured, grout the corner like any other joint. The grout fills the small gap at the face of the joint and provides the finished look. The epoxy does the structural work underneath.
Handling Natural Stone Miters
Natural stone is harder to miter cleanly than porcelain because many stones are less uniform in density and hardness. Take the cuts slowly and support the stone close to the blade to prevent chipping. Some stones, particularly travertine, may need the edge polished after cutting to match the surface finish.
For stone with a polished finish, the mitered edge will show the unfinished interior of the stone after cutting. This is expected. Many installers leave it as-is; others polish the edge to match. We discuss this with clients on natural stone projects before the work starts.