How to Cut Holes in Floors for Ducting
- 1). Measure the duct's length and width. Transfer these measurements onto the subfloor and sill plate, forming a rectangle. If the hole will lead to a heat register, plan to make the hole on the subfloor -- about 3 inches in front of the sill plate.
- 2). Drill a 1/4-inch pilot hole through the subfloor and sill plate, in the center of the rectangle. Go to the level below the subfloor -- either the basement or a lower level of your home -- and locate the pilot hole. Check that the hole you plan to cut will not interfere with any of the lower level's ceiling joists. Adjust the hole if necessary.
- 3). Set a circular saw to the appropriate depth to cut through the subfloor and sill plate. Follow the tracing you made in Step 1 with the saw's blade to cut the hole in the floor.
