how to measure attic ladder swing clearance

How to Measure the Projection Space/Swing Clearance for Attic Ladders

You can watch a video or read this short article about how to measure the projection space or swing clearance for an attic ladder.

The projection clearance, also known as swing clearance is defined as the amount of clearance needed as is determined by the arc of stairway as it swings open.

The three sections involved to determining the arc are (1) the top section in the down position, (2) the center section held out parallel to the floor, and (3) the thickness of the lower section hanging down from the end of the second section. See video below for further explanation.

Step 1:
Drop a plumb bob from the area where you expect the piano hinge to be located down to the floor.

Step 2:
Measure from the dropped plumb bob out to where you expect the bottom of the ladder to contact the floor.

NOTE: if any obstacles are encountered before you reach the minimum safe opening distance, the stairway will not open properly.

Step 3:
If you’re trying to open a stairway through an existing opening such as a hall way or door way, keep in mind that the area above the door facing could present a problem. In order to assure that the stairway will open properly, you should always consider the minimum projection needed in order for the attic stairway to open properly. Remember the projection required will never change regardless of actual floor to ceiling distance.


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3 thoughts on “How to Measure the Projection Space/Swing Clearance for Attic Ladders

  1. Hi,

    I have existing attic ladder opening 24×54″ but it’s situated on a very tight hallway space. In other words, we have a bed room wall right next to the opening so the folding ladder is constrained by swing clearance. Can you provide your ladder specs so we can dertermine if it works with the site condition? Thx.

    1. I’m so sorry for the delay to your question. This blog is not monitored on a daily basis. Someone from Sunset Ladder should contact you soon. For a quicker response, please call (800) 660-1311 with any questions. Thank you.

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