Measure the edge of the door opening around the door and note the length.
Measure a piece of trim for each side of the door and make a mark for its length.
Cut the pieces of trim with a 45 degree angle starting at the mark and going up and out. The angle direction of one piece of trim should be the opposite of the other trim piece. In the end if you laid them side by side, one trim piece would have a 45 degree angled cut moving up from the mark to the left, and the other would have a 45 degree angled cut moving up from the mark to the right.
Measure the third piece of trim, starting several inches in from one end. Make a mark at the starting point and measure the trim for the top of the door opening. Make another mark on the other end of the measurement.
Cut the trim piece starting at the marks and moving out from both ends at a 45 degree angle. The end result should be a piece of trim that is shorter on one side than the other.
Paint the trim and allow it to dry.
Place the trim up against the opening and tack it in place with 1 1/2-inch nails. Put a spare nail on top of the nail heads and tap it with a hammer to countersink the nails. On the top and sides of the trim, where the corners meet, tack nails through the side so that it goes into the other trim piece. Do this on both sides of the corners to secure them.
Fill in over the nail heads with wood putty. Also fill in any gaps between the wood trim pieces. Let the putty dry for a few hours, then sand smooth. Paint over the top to touch up.
Things You Will Need
- Measuring tape
- Circular saw
- Wood putty
- If the trim is a little too long, you can use sandpaper to wear it down. Try sanding the back side of the cut first to see if removing some of the excess on the side will help. If not, sand along the entire cut. If part of the jab is sticking out, use a plane to smooth it or sand it down.