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Maximum Size Penetration in Rated Concrete Floor

Discussion in 'Commercial Building Codes' started by fj80, May 16, 2019.

  1. fj80

    fj80 Sawhorse

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    2015 IBC
    Renovation to an existing condo in a high-rise tower. Original construction is Type II-A and use is R-2.

    An existing bathtub was removed and a new tile shower is to be installed in same place. When tub was removed it revealed a 6"x12" opening in the concrete slab for the waste line. Slab is 8-1/2" thick. There is another condo unit below and the slab opening is open to the ceiling plenum of the unit below.

    We need to infill the opening with something to provide a solid substrate for the new tile floor of the shower.

    First idea was to fill the opening with dry-pack mortar and a pipe sleeve for the waste line (and support the bottom of the mortar with a steel plate with L-brackets drilled into the edges of the slab opening). The problem with this is that it would leave no ability to get access to the pipe, from above inside the unit, in the future if something went wrong or someone wanted to remodel in the future.

    So second idea is to fill the opening with a high density foam block that would be firm enough to support the new shower tile floor but still be removable if needed in the future. But this would not be a fire-rated material. So my question is- is a penetration of this size allowed in a 1-hour rated floor without filling it solid with a fire-rated material?

    I'm reading IBC 714.4 but it's pretty confusing.
     
  2. RLGA

    RLGA Sawhorse

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    It would be a through-penetration and the assembly used would need to be tested achieving a minimum 1-hour F- and T-ratings.
     
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  3. ADAguy

    ADAguy Registered User

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    Love condos !
     
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  4. steveray

    steveray Sawhorse

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    You will have the rating of the floor system and the rating of the tenant separation.....The latter is what you need to protect to....it would be 30 min in a IIB building, but for IIA, I agree with Ron, 1 hour opening protective...
     
  5. jar546

    jar546 *****istrator

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    So I guess I could maybe, possibly assume this is not a post tension slab? Do you know?
     
  6. jar546

    jar546 *****istrator

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    I see rebar dowels in your future.
     
  7. my250r11

    my250r11 Sawhorse

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    not sure how it made it thru with that size of unprotected opening in the first place
     
  8. Builder Bob

    Builder Bob Sawhorse

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    May not require floor slab to be rated if chase walls were used to isolate waste piping. A false soffit or chase is often used to eliminate the need for floor rating at restrooms DWV lines.
     

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