[help] Problematic basement stairway, alternating tread stairs code compliance

[Giginw]

Hi all,

I have a very tight stairway space leading from first floor to basement. I can't really do spiral stairway since the opening width is only 3 ft (not sure if I can use hinged floor hatch on the floor so it can be used as hallway when I don't go to basement. Example: https://pin.it/61vjrUJ).

I also thought about U turn stairway but I was told the landing needs to be at least 3 ft and the headroom should be at least 80 in (the current basement ceiling is 7ft so might not enough headroom for switchback landing).

I finally saw sth that seems to be able to solve the problems. I was wondering if NYC code allows alternating tread stairway? If this is not an option, I will have to knock down the basement foundation wall, gas pipes, water mainline and sewage pipes.

In that case, I'll just use electricity to replace gas, using 12 ductless mini split units for heating and cooling, induction cooktop for cooking and 2 electrical heat pump water heaters for two families.

This link explained the benefit of using alternating stairway in narrow space:
https://salaarc.com/blog/alternating-tread-stair/

This link explained the OSHA and IBC standards:
https://blog.lapeyrestair.com/ships-ladder-stairs-code-requirements

Any suggestion will be deeply appreciated.

Thank you!

 

[e hilton]

They are awkward to use. Regardless of code, I would only use it for rare access. If i thought i would be in the basement every week, i would find another solution.

 

[bill1952]

I don't like them, and not sure if a ladder or ships ladder isn't better. If the basement also has outside access or is not used except for mechanical - furnace/boiler/hey/etc - ok. But washer dryer, storage even, not so good. Very hard to carry things.

I think I would try for exterior access and avoid trap door.