10-23-2012, 07:28 PM
1. Use a miter box, as suggested - either power (preferred) or manual. Mark the reveal (1/8" ) on the face of the frame at each corner and at a few spots along the the length.
Cut the first (long side) miter, then hold the mitered piece up to the frame and mark the second miter on the same piece.
Follow around the 4 sides in this manner.
Do not install nails in the last 12 inches of any of the 4 pieces until you have them all tacked up - this will allow you to adjust each of the miters.
Glue (wood glue) each miter joint.
A finish nail gun will help immensely in this task.
2. Use window and door (minimally expanding) spray insulation. DO NOT use regular spray insulation - it can bow the frame.
3. You can use Liquid Nails, but I would still nail some finish nails into the attic stair frame, and into the edge of the miter from one piece to the next.
You might want to consider renting a nail gun/compressor for this.
Cut the first (long side) miter, then hold the mitered piece up to the frame and mark the second miter on the same piece.
Follow around the 4 sides in this manner.
Do not install nails in the last 12 inches of any of the 4 pieces until you have them all tacked up - this will allow you to adjust each of the miters.
Glue (wood glue) each miter joint.
A finish nail gun will help immensely in this task.
2. Use window and door (minimally expanding) spray insulation. DO NOT use regular spray insulation - it can bow the frame.
3. You can use Liquid Nails, but I would still nail some finish nails into the attic stair frame, and into the edge of the miter from one piece to the next.
You might want to consider renting a nail gun/compressor for this.