Has anyone built/used alternating tread stairs, also known as "Jefferson stairs"? I've been putting in a second floor in my workshop, second floor will be accessed once a day, 140.5" from the first floor. Use will be dust-free hobbies, and for any "large equipment" I'd be lifting it via a hatch in the floor. Widest I can make the stairs is 30" due to building geometry.
First off, I've evaluated installing an attic ladder, and that just won't work. That leaves a normal set of stairs (likely with a 90 or 180 turn) or a compact alternating tread design. I've never used this style before, but I need to finalize my stair design (and build them) before continuing with my second floor decking. I would like to save as much floor space as possible.
There are companies that make these - though they indicate some circumstances aren't code compliant. Some big box stores sell a stair kit (and additional risers) in this design - from an Italian company.
Ignoring construction methods (as I would secure the treads better), this is the style I'm referring to:
https://www.ana-white.com/blog/2015/...ng-stairs-loft
Any thoughts/suggestions would be appreciated.