How to Trim Out a Window With 1X4s

You can buy all kinds of window trim, including formal, fancy styles, but sometimes you want something simpler. If you have a workshop, tool shed or very rustic cabin that needs interior window trim, and you want it to look as simple as possible, buy a few straight one-by-fours. They can be cut and installed just like trim, and will serve the same function of dressing the window while covering the gaps between the window casing and the wall.

Things You'll Need

• Tape measure
• Level
• Pencil
• 1-inch by 4-inch boards, enough to span each side of the window
• Miter saw
• Trim nail gun
• Caulk
• Caulk gun
• Paint
• Paint brush

Instructions

1. Measure the top horizontal span of the window casing, the piece of wood at the perimeter of the window opening. Transfer the measurement to a one-by-four. Put the marks on one side of the board and leave at least 6 inches of space beyond each mark.

2. Lay the wood on a miter saw, with the marked edge facing the back of the saw, toward the blade. Line up one mark with the blade, then swivel the blade to 45 degrees outward, so it's pointing away from the measured section of the board. Make the cut.

3. Move the board so its second mark is lined up with the blade. Turn the blade to 45 degrees in the other direction, again pointing away from the measured section of the board. Cut it. The length of the board will be shorter on one edge than the other because of the mitered cuts on both ends.

4. Set the board against the wall, over the window opening. Place the shorter edge of the board facing down, toward the window. The miter cuts on either end should start at the corners or the window and flare out and up.

5. Secure the board with a trim nail gun, putting nails every 10 or 12 inches along the top and bottom edges.

6. Repeat the process for the sides and bottom of the window opening, letting the miter ends of the boards make the corners.

7. Caulk all around the boards where they meet the wall and the window casing. Let the caulk dry for a day. Paint the boards.

References

• Kelleher Corp.: How to Mitre Moldings