1. Prepare the Existing Opening
Remove all of the trim surrounding the existing opening using a hammer. Attach temporary support boards to keep the ladder secure for removal.
2. Remove Existing Attic Stairs
*Tip- Tie ladder sections together to keep them from separating during removal.
Remove the existing attic stairs with a reciprocating saw.
3. Inspect the Opening
Inspect the opening and make sure all of the fasteners and any previous blocking are removed. The opening must meet a minimum structural requirement of a 2x6 header and joist system with a rough opening larger than the attic stairs.
4. Attach Temporary Support Boards
Attach temporary support boards at least 4 inches wider than the opening using a drill and 3" deck screws. Fasten the boards to hold the frame of the new ladder on the short side without impeding the ability to open the door. The temporary supports need to be placed centered with respect to the long dimension of the opening. They will hold the stair in place while it is fastened to the joists and the headers.
5. Secure the Framing
If the ladder is more than 1-1/2" smaller in any dimension than the rough opening, secure additional framing in increments of 2x4s (1-1/2" thick) and 1x4s (3/4" thick) with 3" deck screws or 16d nails at 12" on center spacing. The goal is to get less than a 3/4" gap to fill with shims.
6. Attach a Rope
Install the pull rope on the ladder assembly by threading the rope through the hole in the door. Then, thread the washer (included in the attic ladder kit) onto the rope on the upper side of the door. Pull the rope through to your desired length so it is long enough to reach from the floor, but not too long to walk underneath when the ladder is in the closed position. Tie a knot on the upper side of the washer. The washer prevents the knot from slipping back through the hole when the rope is pulled.
7. Position the Ladder
You will need two people for this step. One person should be in the attic, and the other should be on the lower floor.
Leading with the hinge side of the ladder, lift the ladder assembly up into the opening using the temporary support boards as a guide. Ensure the hinge side is on the correct end.
8. Pull the Ladder Up
Pull the ladder up over the opening, resting it on the temporary supports. Center the ladder width wise, but rest the hinge side of the ladder against the header support. Ensure the temporary support boards are not preventing the plywood door from opening.
9. Secure the Ladder
Secure ladder with two 3" deck screws on the hinge side to hold it in place.
10. Square the Corners
Measure diagonally to make sure the frame has square corners. If the diagonal measurements are different, place shims on the sides or corners so the two diagonal dimensions are equal.
11. Secure the Ladder
Attach two screws to hold the ladder on the end opposite the hinge.
12. Pre-Drill the Header Side
Once the ladder is positioned correctly, pre-drill and insert four 1/4" x 3" hex lag bolts into the header side. If needed, add additional shims along the midline of the long sides of the ladder.
13. Insert Lag Bolts
Pre-drill and insert two 1/4" x 3" hex lag bolts on either long side (four total) of the ladder into the side supports.
14. Remove the temporary support boards.
15. Set the Height
If the ladder legs are too long, fold the ladder at the lowest joint and measure from the hinge to the floor. Unfold the lowest section of the ladder, and cut the straight legs just enough for the feet to sit correctly on the floor. Use a hacksaw if the ladder is metal, and a wood saw if the ladder is wood. Re-attach the feet using wrenches.
16. Add the Finishing Touches
Re-install the trim with a nailer and finish nails, and paint the door to match.
Congratulations! You have replaced your attic ladder!