How to Keep a Diamond Pattern in Shower Level & Straight

Install the straight tile all the way up to the area where you need your diamond pattern to start. You need the starting course for the diamond pattern to be completely level, and so long as you checked your straight tile every few rows on the way up this shouldn’t be a problem. Make any necessary adjustments with tile wedges and spacers to get that final row of straight tile level.

Cut down some wood strips to a length that is slightly longer than the overall height of your diamond pattern. For example, if your pattern is 12 inches high, cut your strips at 14 inches. Use the level to draw a plumb line up the wall that lines up with the outer plumb line of your straight tile installation. Screw these wood strips into place on the outside edge of your diamond pattern area, using the plumb line as a reference.

Make full diagonal cuts on your tile wet saw. Cut pieces corner to corner across the pieces to create the half diagonals, which are triangles. The most common diamond pattern is a row of diagonal cuts on the bottom, a row of diagonal cuts on the top, and in between are full pieces set on a diagonal in between. Make an appropriate number of cuts to fill the top and bottom of your pattern around the shower.

Center the back wall. Measure the width, divide by two, and mark that area with a pencil. Set your first piece of diagonal tile on top of this mark, so the inside corners have the same-size cuts. Use the opposite ends of those cuts to wrap the pattern into the side walls. Spread thin-set mortar onto the wall in your pattern area. Set a few of your triangle pieces end to end out from your starting point. Install the back wall first.

Ensure your first row of triangle pieces are set on top of the level row of straight. On top of these triangles, install full pieces of tile on a diagonal. Then, after you have placed the full tile pieces, place the topmost triangle pieces, which are flipped upside down so that the long, flat part of the triangle is facing up. Use tile spacers and wedges to keep the joints uniform, and use the level to guide the top of your pattern.

Wrap the inside corner cuts so that they continue the pattern around the side walls. Make the necessary cuts on your tile wet saw. Mark the pieces with a pencil and tape measure. Continue running your full triangle pieces until you reach the wooden strips that define your finished edge. Make the necessary cuts and install them. The wooden strips hold them in place so they don’t slide. Wait 24 hours before finishing the rest of your wall tile above the diagonal pattern.