How to Build a Door Threshold With Wood

Lay threshold on a piece of 1/4-inch hardboard. Line up one of the threshold's long edges with the hardboard's edge. Trace along the threshold's other long edge and remove it from the hardboard. Cut the hardboard along the traced line with a circular saw. Then, cut the strip to approximately 12 inches long.

Lay the strip on the floor in the door opening. Hold one of its ends against a side jamb in the same way the new threshold will lay against it.

Locate the largest gap between the hardboard strip and the door jamb. Open the scribes to span this gap. Trace the scribes over the hardboard, following the door jamb's contours. Remove the strip from the door opening.

Cut the hardboard strip along the line with a jigsaw. Use a saw rasp to clean up the cut line. Test fit the hardboard strip against the door jamb. Make any minor adjustments with the saw rasp until the strip follows the jamb's contours as closely as possible.

Measure the door opening's width from the widest point. Transfer this measurement to the new wood threshold. Cut the threshold straight across with the jigsaw.

Lay the threshold upside down. Hold the hardboard strip on the threshold and trace around its edge. Flip the hardboard strip over to create a mirror image and lay it on the threshold's other end. Trace around the strip's edges again and set it aside.

Cut the wood threshold following the tracings you just made. Use the saw rasp to clean up the cut edges. Place the threshold in the door opening. Use the saw rasp to make any minor adjustments.