How to Install an Attic Ladder Perpendicular to the Joist

Locate and mark the joists in your ceiling using a stud finder. Cut a hole between these marks large enough to see the joists using a hammer and a chisel.

Measure the width of your ladder and mark a rectangle around the opening in the ceiling so that the shorter sides reflect the width of the ladder and run perpendicular to the joists. The longer sides will run parallel to the joists.

Cut out the ceiling material using a hand saw or a jigsaw along the lines you’ve marked, but do not cut the joists.

Climb up into the opening using a step ladder and mark the edge of the opening at both short ends on top of the joists.

Cut two boards that are the same size as the joists so that they are long enough to extend across the joists and to the next joist on either side.

Position each board 24 inches back from the edge of the opening so that they run perpendicularly across the joists on each end. Secure the boards by driving three nails through the board at each joist.

Mark a line three inches back from the edge lines you marked on each joist. Cut the joists at these marks using a handsaw or a jigsaw. Do not cut into the ceiling material.

Measure the distance across the cut joists at each short side of the opening and cut four boards to this length.

Position the first board so it runs perpendicular against the cut joists at one end. Make sure it is square and drive three nails into each end through the header board and into the joist. Place the second board in front of the first board and secure it as well. This creates a double header to which you will install the hinged side of the ladder.

Install the remaining two boards at the other short end of the opening in the same manner.

Measure the distance of the opening along the longer sides between the headers. Cut a board that is the same thickness and width as the joists to this length. If you have not positioned the opening so that you have a joist running along one long side of the opening, cut two stringers instead.

Position the stringer along the unframed side of the opening and hammer three nails through the header boards and into the end of the stringer at each end. The nails must be long enough to go through both header boards and then into the end of the stringer by at least one inch.

Install your attic ladder according to the manufacturer’s instructions so that the hinged side of the ladder is secured to one of the double headers running along the short sides of the opening.