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Sistering attic joists.

Discussion in 'Residential Building Codes' started by David Schreck, Sep 12, 2019.

  1. David Schreck

    David Schreck Registered User

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    I am planning to finish a space in my attic. The existing joists are 2x6 and running about 13' from support to support on either side of center. Because of this, I am planning to attach sister 2x8s to each joist.

    The planned room will sit over a load bearing wall, however, part of the existing joist structure has a recessed ceiling from our master bedroom.

    My question is, when I attach the sister joists, do they need to span all the way from the center load bearing wall to the outer support walls? I am not sure how to do that with the recessed area. Or can I just go from one outer support wall across the center support wall and end them with no support. I will try to attack picture. Green is proposed room walls, orange below attic is the supporting center wall.
    [​IMG]
     
  2. David Schreck

    David Schreck Registered User

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  3. fatboy

    fatboy Administrator

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    I would require an registered design professional's stamp on any design like this.

    Good luck
     
    Ty J. and my250r11 like this.
  4. e hilton

    e hilton Bronze Member

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    Agree with fatboy. And my 2 cents ... not going to work. What is supporting the right ends of the existing joists where they die into the tray ceiling? A header?
     
  5. Ty J.

    Ty J. Sawhorse

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    Eng. design req'd.

    Fatboy has it.
     
    ADAguy likes this.

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