How to Miter Corner Trim
- 1). Measure the length of one wall, from the corner out. Pick a piece of trim longer than the wall. Use a pencil to mark out the measurement on the trim, with a starting mark and an ending mark.
- 2). Lay the trim on the miter saw, sitting the way it will be positioned on the wall. Slide it so the side that will go in the corner is under the blade.
- 3). Swivel the blade to a 45-degree position, making it point in toward the main part of the trim. Hold the piece firmly. Engage the saw and bring it down through the piece.
- 4). Repeat the process for the adjacent piece that will come off the other side of the corner. This time, position the opposite end of the piece under the blade (again, the end that will sit in the corner). Swivel the blade to 45 degrees toward the piece, which will mean turning it in the opposite direction as before. Make the cut.
- 5). Set the two pieces of trim in the corner to test the miter. If the seam between them is not tight, re-cut them, adjusting the blade of the miter saw to be slightly more or less than 45 degrees, as needed.
- 6). Get the seam right, then cut the opposite ends of each piece as needed to fit on the wall. Secure the trim by shooting in nails at the top and bottom of each piece, every foot or so, with a trim nail gun.
