Hi,
I am looking for some information or suggestions for a problem discovered recently. I built my house about 4 years ago and although I was the General Contractor, I had the framing done through a sub contractor. I poured 9 ft. basement walls and built a 1 ft. 2x6 knee wall that I set the joists on. This gave me a 10ft. basement ceiling height. Anyway, I noticed that the knee wall parallel to the floor joist (the one the long rim-joist sits on) is out of plumb about 1/2 inch in 12 inches. This is a pretty significant lean. Oddly enough, my rim-joist is plumb and all of my mechanicals are still tight to the top of the knee wall. This gives me the indication that this happened during construction and has not moved since. I did notice that there is not any bridging in between the last joist and the rim-joist. I am not a framer, but I have an understanding of the basics. Before I consult a structural engineer, I would be interested in some feedback. How much weight is on a rim-joist? Could it have just been the weight of the walls above that caused the knee wall to move? The exterior walls are 2x4 and the knee wall is 2x6 with the rim-joist sitting on the outside of the wall. What about adding another rim-joist inside of the original one? Any suggestions?

Which way is the knee wall leaning? Has the top of the rim joist moved relative to the sole plate above it? The amount of weight on that rim joist depends on a bunch of things you haven't told us...how many stories are above it? Does roof load come down on it? Is the floor above the knee wall level in theat area? Probably the recommendation will be to install solid bridging between the rim joist and the next joist in, in line with the existing bridging, and possibly in between. There isn't much you can do about the leaning knee wall at this point.

Sounds like the wall was installed out of plumb in the first place. It will not move once the weight is placed on it. Besides the first floor sub-floor would tie it from moving out or in anyway. Are the upper level walls above it plumb? If so it happened when the house was built.
Other then being out of plumb and cosmetic what issues are you having with it?
The weight of the wall is not going to push the knee wall out of plumb. Is the floor joist or rim joist that is sitting on this wall parallel to the other floor joists or bowing out? If its parallel to the other joists then the movement was where it was fastened to the cement wall. If its bowed it sounds like the framing was installed out of plumb.
To become unstable the lean would need to be at least one half the distance of the thickness of the wall. 2x6 would be three inches.

Wow you guys are great. Thank you for the replies. I am not concerned about the cosmetics, I am more concerned with the structural issues. The wall is leaning out. How does the first floor sub-floor tie into the knee wall to keep it from moving? The house is a ranch with a bonus room above the garage. The roof is all hip with load on the exterior walls. My understanding is the roof is supposed to be considered a "self-supporting" roof, but obviously there is load on the exterior walls. I have checked all of the knee walls and both of them running parallel to the joist are out of plumb. The wall on the opposite end of the house in only out about a 1/4" though. All of the others are pretty plumb. The knee wall that is out 1/2" is out where the steel I beam sits on top of the foundation. The knee wall at that point is notched out with only a single top plate connecting it to the knee wall on the other side of the beam. We used a triple top plate on all of the knee walls. Also, the knee wall on the opposite end of the house that is out a 1/4" is only that far out at the beam also.
The rim-joist above the knee walls are plumb, the floor above the walls is level, and the exterior walls are plumb. I really think this happened during construction and its secure, it just bugs me to death as I was considering not using knee walls for this very reason. My plan, if it sounds feasible to you guys, is to double the rim-joists running parallel to the floor joist and place solid bridging. Thanks for the help.

Oh, one other thing, as I mentioned earlier my ductwork is still tight to the top of the knee wall. There is a 90 right at the top of the knee wall that is tight to the top of the wall. I checked the duct work and it cannot move back and forth. This leads me to believe that as you guys mentioned, maybe it was framed out of plumb. I just want to be sure its not moving.
Thanks

The plot thickens. This is a good example of why it's dangerous to try to answer questions like this without seeing the actual conditions. Do I understand correctly that the knee wall is leaning ONLY where the steel beam is located? Maybe there were some "fine adjustments" made when the steel beam was installed, you know, the kind they make with sledge hammers.

Oh, and by the way, I'd like to get a copy of the plans for that "self-supporting" roof, so I can use it before they get a patent on it...will save my clients a lot of money on walls, beams, girders, etc.

Richard,
Thanks for the reply. It is greatly appreciated. I was being rather facetious about the self-supporting roof. That was how it was advertised to me when I was purchasing the prints. I thought it was funny.
The wall is not out of plumb only at the beam. This is just the worst spot. It is about 1/4" to 3/8" out all along the wall. Where the wall meets the beam is where it is out 1/2" to 5/8".
I am not sure that I follow you on the "fine adjustments." I know that framers beat walls all over the place to line them up, but this knee wall was framed long after the beam was set. What would be a reason to knock it out of plumb on purpose? Although, I could see them not plumbing it at all.
Your help is appreciated.
Thanks

Here are a couple of pictures. This might help visualize the issue.


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Well, I was having fun with you about the "self-supporting" roof. Maybe the beam was slightly longer than needed, and the framers were forced to warp the knee walls to get around them. No way to know now. Is there a bulge in the outside wall at those locations?

Thanks again Richard for the reply. Funny that you should mention that. The beam was about a foot long when it arrived. They just cut it on site instead of taking it back and getting a crane again etc... The thing that concerned me, was that I had not noticed it before. As far as noticing it on the outside, you have to really look for it to find it. A few spots have just a slight bow, but nothing noticeable. I had thought about just beating it back over, but that would require fiber cement siding repairs as well as drywall and everything else. Anyway, if the general conscientious is that the downward pressure of the roof and walls should not force the knee walls out, then I feel more comfortable. I fully understand that it is difficult to make suggestions over the internet, I am just looking for obvious structural issues that I may be missing. I have marked the beam and the wall to be sure that it is not moving. I had thought about framing an interior wall (going to finish the basement eventually anyway) and tying it to the knee wall. Or maybe even trying some metal bracing and bolting it to the knee walls running in the opposite direction? Really, I am just throwing things out there - should I even try and fix it? Thanks again.

Vugger,

One thing I would check to be sure is where the 1/2" "came from" for lack of a better term. In other words, if the top is leaning out a 1/2", then is there now a 1/4" gap where the sill plate meets the concrete? I assume (I hope) the sill plate is anchored to the top of the foundation, does it look like the washer and nut from the anchor bolt are "ripping through" the sill plate? The vertical 2x6's that make up the knee wall, are they separating from the sill plate, about a 1/4"?

The reason for all the questions is it will give you clues on when this took place. If there are no gaps at all or the nuts/washers aren't ripping through the sill plate....great, it was probably done during construction. If there are gaps then it is may have occured after the fact. Let us know what you find.

Also Richard, do you need a partner for your new weightless roof business venture?

Jay,
Thanks for the reply. That is a good point. The anchor bolts were in place, although initially they were not very tight. I went back when I noticed this and tightened all of them down. They seemed to only be hand tight. There is a slight gap between the top plate and the concrete, about 1/4". Also, the studs in the knee wall have separated from the bottom plate of the knee wall about 3/8". This separation only occurs at the areas where the beam forced a break in the wall, where the wall is the most out of plumb. The wall on the opposite end of the house only has a slight lifting of the sill plate with no separation between the studs and top/bottom plates. Is it possible the anchor bolts not being tight enough helped the wall to move?
Thanks again for the help.

It is possible that the downward pressure of the house has forced the knee walls out, because the load is placed off center on the knee walls, by means of the rim joist which is located on the far outer edge. The question then is, why is the tilt greater at the beam than elsewhere? That I cannot answer. Also, even though there is roof load, the loads are not that great...however, with a hip roof above, the loads at the beam (center of the house) would be greater than the loads near the corners.

Thanks for the reply Richard. Yeah, the more that I look at it, the more I think it has moved and was not framed that way. One thing still has me thinking though - All of my mechanicals are still tight to the top of the knee wall. This would tell me that it has not moved since the initial loads were placed on the wall. Any idea's for repairs? Should I jack it up and knock the wall back over? Double rim-joist, metal reinforcement? Or, should I call in an engineer to take a look? I appreciate all of the help.
Thanks

The only way that a wall should tilt from strictly downward force is if top of the concrete was way out of level, even if the load is concentrated on the outside of the knee wall. The reason I say this is that walls 10 times as high wouldn't stand a chance - which there are 1000's of in the state & country.

Without seeing it first hand, I'd say that either the concrete is way out of level, or there is some unknown lateral force there.

But like Richard said, it seems like the beam is the key, just figuring out the key to what is a different story.

One things for sure though, I'd get the structural engineer to look at it. You may have read many times in this forum that you need to diagnose the problem before trying to solve it.

Ummm... As far as the engineer is concerned... any idea why the cheapest quote from a whole bunch is just under $1,000? Are you kidding me. $250 an hour with a minimum four hour charge to take a look at a wall. I understand there is more to it than looking at the wall, but cmon... sheesh! I may just have to patent my "self-supporting" roof. Please tell me there is an alternative? I could finish half my basement for that.

This message has been edited. Last edited by: vugger,

It's a public relations ploy intended to build esteem for the b*$&?#ds. Or maybe it's a polite way of saying don't bother me with your little trifles, I'm busy designing skyscrapers. And then half of them will have you jumping through hoops to cover their backsides if you did manage to get them out there. I routinely do stuff like this free of charge. You'd be amazed what comes of it.

Richard,
Thanks again for the reply. I can only imagine what you run into out in the field. I am sure the main reason for the inflated prices and a long wait, was because they did not want to deal with something like that.
After two days of searching, I did finally get in touch with 2 engineers that were helpful and extremely nice. The first one that I talked with was rather stumped, but thought maybe my foundation wall had pushed in causing the knee wall to be out of plumb. He gave me some things to check out, but that does not seem to be the problem.
The second guy that I talked to felt that it must have been done during construction because if there was lateral movement in the floor, as one wall pushed out, the opposite wall would have pulled inward. The opposite wall is pushed out 1/4". They both told me that there is nowhere for the wall to go because its all tied into the floor and there is not very much weight on top of that knee wall. Neither one felt it was a big enough of a concern to take a look at it. They both said they could come out and look at it and charge me to write a letter stating what they already told me over the phone. For now, I guess that I will just watch it and make sure it does not move. I have some other framing questions, but I will start a new thread just in case there are any other suggestions.
Thanks again.

I'm glad you finally found people who realize that with their professional license comes public responsibility. Anyone who asks politely can have two hours of my time, free of charge and obligation, and I firmly believe that all professionals owe that to the community that licenses them to practice. That's one reason I make such a pest of myself on here.

I suspect that you don't really have a problem. If I could see everything first hand, I'd put it in writing, too. An hour's worth of time can buy one a heck of a lot of good will.

Richard,

Care to move to Minnesota?? All the snow you can eat....