How Do You Messure For A Replacement Attic Access Ladder

The rough opening for a full size attic.
How do you messure for a replacement attic access ladder. Full size attic ladders usually need an opening in the ceiling that is at least 22 1 2 x 54 inches. If you re installing pull down attic stairs for the first time you ll likely need to cut the hole yourself. For smaller attic ladder openings with a minimum measurement of 18 x 24 you will need to measure from the finished floor to the attic floor. Choose the right attic ladder s rough opening dimensions.
The length is simply the dimension between the two pieces of lumber that form the end of the opening. Attic ladders are sized based on the rough opening. Also make sure the space leading to the attic ladder is comfortable enough to carry all the types of objects you ll bring to the attic. Do not measure the inside of the box frame and as that is not a true rough opening measurement.
Step 2 place a tape measure at the left side of the attic opening on the inside edge of any trim molding but the outside of the actual attic ladder frame. So with a 24 on center and framing lumber being 1 1 2 thick the dimension between the inside edges of the two joists is 22 1 2 24 3 4 3 4. That s dimensions between the framing of your attic joists which is typically 24 on center. First if there is an existing stairway measure from the outside to the outside of the existing box frame.
Width dimensions of the ladder when installed on the attic s floor. The rough opening is the length vs. If your home already has an access hatch and you re only adding a ladder you can skip to the next step for instructions on how to install a ladder. Also make sure there is a suitable landing space in the attic so you can safely mount and dismount the ladder while carrying items.
Most attic ladders cover a range of ceiling heights so it s important to know the exact measurement you re working with. You can stand on the attic ladder to take the measurements if you feel it is steady enough to do so.