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Header required under first riser

casabian | Posted in Building Code Questions on

Having some headroom issues and want to push this header back…how much space is required from the front of the stair? 4 inches?

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Replies

  1. Expert Member
    Michael Maines | | #1

    Casabian, I'm not sure what you're asking... for a code-compliant egress stair in the US you usually need 80" clear vertically above the stair nosing, 36" clear width above handrail height, max. 7 3/4" risers and min. 10" treads (that's the stringer cut, not the actual tread with nosing, which is usually deeper than 10"). Some places have slightly different requirements, and not all stairs need to meet egress code.

    A sketch of your situation would be helpful.

  2. casabian | | #2

    Sorry, I don't understand why GBA only allows 3MB files when most iPhone pictures are above that. Anyone have a good way around that?

    Here is the photo. I think we figured out that 3 inches is the code for the area from the beginning of the first riser going upstairs. We moved the header back about 15 inches from what you see in this picture to allow for more headroom going down the basement stairs.

    Thank you for responding!
    ed

    1. Expert Member
      Michael Maines | | #5

      "3 inches is the code for the area from the beginning of the first riser going upstairs." From there to where? Sorry but it's still not clear what you're asking. Perhaps it's a question about how much bearing area the stringers need where they land on the subfloor?

      1. casabian | | #6

        Yes thank you for translating for me :) how much bearing area do the stringers need where they land on the subfloor?

        1. Expert Member
          NICK KEENAN | | #7

          I don't think it's a matter so much of bearing area, but the stringer has to land on a joist, it can't land on the subfloor between joists. Usually you have a doubled joist where the stringer lands and that's the edge of the opening. I think from your earlier message you've got it fixed that way now.

        2. Expert Member
          Michael Maines | | #8

          You don't need much bearing area. Usually just 1 1/2" x 1 1/2" at each stringer is enough. In fact sometimes to gain extra headroom I set the exposed face of the stair header at the same plane as the first riser and extend the stringers down to rest on face-mounted joist hangers.

          It is important, however, to fully support whatever the horizontal cut is at the bottom of the stringer, so the stringer doesn't split under a heavy load. You might be able to cheat it a bit but in your case it looks like you might need to have the face of the header back about 8" from the first riser.

          Another trick to gain headroom is that sometimes you can set the header on an angle, rotated to match the slope of the stairs. It reduces how much weight the header can support, but they are usually oversized.

  3. casabian | | #3

    Quick tech tip for everyone on here with a recent iPhone that produces pictures that are above GBAs 3MB limit.

    Take a screenshot of your photo, which will reduce the size by 1/3.

    (But really, it's 2021 — at least up it to 5MB)

    1. Expert Member
      MALCOLM TAYLOR | | #4

      You can also use a free photo resizing site like this: http://www.picresize.com

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