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  1. #1
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    Default Foundation knee wall bracing

    It appears that additional bracing or shear walls are needed in these two areas. This is new construction, the foundation steps down in these areas. Knee wall 2x4 studs are about 4 feet tall in these areas.

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  2. #2
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    Default Re: Foundation knee wall bracing

    I agree, that is underbuilt and was probably never viewed by a building inspector. One stud is cock-eyed and another is bowed. Call for repair. My suggestion would be plywood sheathing at this point. But I'm not the engineer or the architect. The builder could not have seen that in the plans, IMO.

    John Kogel, RHI, BC HI Lic #47455
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  3. #3
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    Default Re: Foundation knee wall bracing

    Trent,

    The vapor barrier installed on the floor joist looks like trouble down the road .
    * traps moisture.
    .

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  4. #4
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    Default Re: Foundation knee wall bracing

    Quote Originally Posted by Trent Tarter View Post
    It appears that additional bracing or shear walls are needed in these two areas. This is new construction, the foundation steps down in these areas. Knee wall 2x4 studs are about 4 feet tall in these areas.
    Were the framing members really that crooked or is there something odd going on with your camera that is causing your images to be distorted?


  5. #5
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    Default Re: Foundation knee wall bracing

    Looks like a temporary support while someone was waiting on the delivery of a replacement mid-span beam or gluelam. Orphaned pier. Those TJI's above? Camera affect in 2nd photo or are joists offset? Whats the span?

    Not structurally sufficient in any case even if mere partitions. Not actually proper walls or knee walls in any case - even if not intended to be load bearing - they are "floating" no tie-in wall ends, etc.


  6. #6
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    Default Re: Foundation knee wall bracing

    Could we be jumping the gun saying it's under built.... I see a single top plate, which is ok because the studs are stacked with the floor joist. It appears anchor bolts are present, not sure if they are to code, but I see a few in the pics. Treated plate on the concrete. This is also an interior wall, it may not need to be a shear wall?? Just because it's bearing doesn't mean it has to also be a shear wall does it?

    I also would be concerned with the plastic on the underside of the joist. This could cause a moisture problem in the joist depending on the climate. No insulation on the outsides either.

    Randy Gordon, construction
    Michigan Building Inspector/Plan Reviewer

  7. #7
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    Default Re: Foundation knee wall bracing

    Quote Originally Posted by Door Guy View Post
    I also would be concerned with the plastic on the underside of the joist. This could cause a moisture problem in the joist depending on the climate. No insulation on the outsides either.
    What plastic under the joists? I don't see any.

    But that insulation job is "interesting" to say the least; I suspect that's some sort of water supply piping wrapped in fiberglass batts in the second picture.


  8. #8
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    Default Re: Foundation knee wall bracing

    Quote Originally Posted by Corn Walker View Post
    What plastic under the joists? I don't see any.

    But that insulation job is "interesting" to say the least; I suspect that's some sort of water supply piping wrapped in fiberglass batts in the second picture.
    I think I see plastic in the pics?? Please let me know if my eyes are deceiving me...

    Randy Gordon, construction
    Michigan Building Inspector/Plan Reviewer

  9. #9
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    Default Re: Foundation knee wall bracing

    Quote Originally Posted by Door Guy View Post
    I think I see plastic in the pics?? Please let me know if my eyes are deceiving me...
    There appears to be 6 mil black poly poorly laid on the ground, but under the joists is insulation retaining line to keep the batts from falling down.


  10. #10
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    Default Re: Foundation knee wall bracing

    Quote Originally Posted by Corn Walker View Post
    There appears to be 6 mil black poly poorly laid on the ground, but under the joists is insulation retaining line to keep the batts from falling down.
    Hmmm... you could be right. It really looks there is a sheen under the fiberglass when I view the pics. Maybe my eyes are failing me

    Randy Gordon, construction
    Michigan Building Inspector/Plan Reviewer

  11. #11
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    Default Re: Foundation knee wall bracing

    Quote Originally Posted by Door Guy View Post
    Could we be jumping the gun saying it's under built....
    No, not jumping the gun. There is nothing correct about this, even a "partition" and is questionable "temporary support".




  12. #12
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    Default Re: Foundation knee wall bracing

    Quote Originally Posted by H.G. Watson, Sr. View Post
    No, not jumping the gun. There is nothing correct about this, even a "partition" and is questionable "temporary support".
    Care to educate the rest of us so we can learn?


  13. #13
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    Default Re: Foundation knee wall bracing

    Quote Originally Posted by Corn Walker View Post
    Care to educate the rest of us so we can learn?
    Specifically, there are a few things we don't know from the picture and therefore don't know if everything is wrong, or just some things.

    • We don't know if there is a bearing wall above.
    • We don't know if this wall is a required bearing wall and/or shear wall and what the load profile is.
    • We don't know the depth of the joists.
    • We don't know if there are web stiffeners at the top plate.
    • We don't know if the appearance of being crooked or skewed is because of the camera or not (I suspect the camera is to blame here).


    So I'm wondering, with all of the things we don't know, what based on the pictures can we determine is wrong without needing to know the answers to the above.


  14. #14
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    Default Re: Foundation knee wall bracing

    What do we know? We know that those are not conventional lumber floor joists above. They are likely I-Joists or Floor Trusses which may or may not be all wood floor trusses, and may or may not be trimmable. I cannot make out the entirety of markings on the left most exposed chord or flange. There is, however, not a doubt in my mind that the floor/ceiling assembly system is not conventional lumber.

    That 4' high "structure" is NOT a proper wall, knee-wall, partition, or otherwise. It is not tied in, has no structural stability (even for a partition) and does not belong in contact or compressing the floor system above in the manner it presents itself.

    There are two photos. Despite your concerns about photo affect, and even if "photo-shopped" there are too many constants if you review the photos in a much larger mode and overlay grid that indicate you are not merely viewing a lense distortion, however, irrespective of this concern of yours, the so-called "wall" is still not correct.

    It (no matter the circumstances) is not correct as pictured in place, and has the potential to interfere with the floor/ceiling system assembly above.

    Last edited by H.G. Watson, Sr.; 01-10-2011 at 03:00 PM.

  15. #15
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    Default Re: Foundation knee wall bracing

    Weyerhauser (among others) allow for the use of an intermediate bearing wall to reduce the span of floor joists. Bearing plate is required to be 3-1/2" minimum (5-1/2" in some instances) with studs positioned directly underneath the joist flange. Web stiffeners are required in all instances, and squash blocks or blocking panels may be required in some (e.g. for shear walls). Joists are nailed into the plate from the top with two 8d toe nails.

    We don't know whether the required things were done, or who the manufacturer of these engineered joists are, but it could have been done properly, we just don't know.

    Here's what I do know - they doubled the stud in the one image where the j-bolt is in the way of properly locating the stud for support. Using the 45 rule, they could have gotten away with a single stud positioned as much as 1-1/2" off center, but they didn't. So the framing contractor had at least half a brain, if not a bit more.

    As for the image perspective, unless you're aligning a hyperbolic grid to the image you can't really correct for the effects of wide-angle lens distortion. You have to compensate for both distance effects (objects in mirror may be closer than they appear) as well as skew effects at the edges and corners.


  16. #16
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    Default Re: Foundation knee wall bracing

    (1) Foundation vent in background is square with the world indicating the stud is askew. (2) Photo was not taken with a wide-angle / fisheye lens.


  17. #17
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    Default Re: Foundation knee wall bracing

    Quote Originally Posted by Jim Hintz View Post
    (1) Foundation vent in background is square with the world indicating the stud is askew. (2) Photo was not taken with a wide-angle / fisheye lens.
    The photo was taken with a Sony Cyber-Shot W310 camera with the focal length set to wide angle mode (5.2mm/28mm equivalent).


  18. #18
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    Default Re: Foundation knee wall bracing

    Quote Originally Posted by Corn Walker View Post
    The photo was taken with a Sony Cyber-Shot W310 camera with the focal length set to wide angle mode (5.2mm/28mm equivalent).
    Even a drunkard could tell that some of the studs in that knee wall are not plumb! The stud immediately right of the foundation vent in the background is closer to the top of the vent than it is at the bottom of the vent - a distance of only 6-8 inches, also, only one cripple stud on the upper footing is askew - leaning to the right at the top, the others appear to be fairly perpendicular. Also, the vertical foundation seam in the far back left corner is not distorted - it's plumb. Finally, I must have missed where the brand and model of the camera were mentioned in the original post.


  19. #19
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    Default Re: Foundation knee wall bracing

    Quote Originally Posted by Jim Hintz View Post
    Finally, I must have missed where the brand and model of the camera were mentioned in the original post.
    And your point is?

    I didn't say the studs were all plumb, only that because of the effects of distortion due to the short focal length we can't say for certain which are out of plumb (if any) or by how much.


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