Hey everyone, first off I apologize if I am not asking or explaining this using the correct terms. I am not a structural engineer but generally do well with physics and construction. I’ve attached a rough drawing I made. Our family had our home significantly damaged by flooding 2 years ago and we have been slowly rebuilding. I hired an engineer to raise the house and another company to pour a new foundation. A wall was framed up from the foundation and the house was set back down on it. The house is a single story home, stick built with a truss roof.
After the house was lowered I realized that a mistake by the concrete contractors had resulted in the new rear foundation wall being about 1.5 inches inset from the house. The engineer that I hired told me he was aware of it and assured me that it would not matter in the slightest structurally and that I could just use slightly thicker foam under the siding so it isn’t noticeable.
I have read through the irc codes ad nauseum and think I understand why he says that, but am hoping someone here with a lot more knowledge than me can help me out.
My questions are:
is this structurally fine?
irc 502.3.3 revised in 2021 seems to indicate that I do not need blocking between the joists since it is less than 24” o.c., is that correct?
the rim joist sits on top of an inch of sheathing. While I’m sure that helps support it, it seems to me that it certainly isn’t a proper load transfer but I don’t really need one since the walls still mainly sit over the fully supported joists and I have joist hangars attaching the rim joist… the question I have is does this overhang preclude attaching a ledger board for a deck? I know you aren’t supposed to attach a deck ledger to a cantilever / overhang. I’m not sure if there is any way this is currently, or could be made to be code compliant with a deck/walkway attached? Tough to do a free standing deck that’s only 4’ wide that close to the house.
(Please excuse the inaccurate scale on the thickness of the anchor bolt. They are 3/4 bolts)
Thank you for helping me understand this. I’ve been working hard to get our home back together and have done most of the work myself because finances are so tight (4 kids, my wife and I…gets pricey) and running into this has me a bit stressed.
I have been through all the code documentation I can find and it’s leaving me with as many questions as answers.
You’re right, I just figured someone here may have run across things like this while doing inspections and may have some idea. I will look for some structural engineer forums as well. Thank you!
I am a home inspector, plus a mechanical engineer by training and good with physics. The problem is that due to the 1.5" offset, the rim joist now has little or no direct bearing on the foundation wall and is only supported by fasteners. Not good. As a structural element, it has lost much of its strength. You could make a big stink about it… However, it were my house, I would just be pragmatic about it. Since this is a one-story home with asphalt shingle roof (presuming), the wall loading is relatively light. Instead of filing the entire gap with foam below, I would suggest the foundation contractor secure a 2x10 or 2x12 directly underneath the rim joist using a requisite number of 1/2 lag bolts to significantly bolster the rim joist and would rest easy at night with that fix.
As Brian mentioned once the band joist moved off the foundation wall the nails attaching the band joists to the floor joists are in pure shear if you attach a deck to it. Better build the deck free standing and cantilever the deck joists on the house side about 12 to 18 inches to allow for your deck footings. You should attach the deck to the house floor joists for lateral support.
What is throwing me, is that the wall appears warped away from the ledger. How did that happen with the tensioner there? I must be seeing this wrong. BTW, you did an amazingly clean cut out.
Happy almost Thanksgiving! Thank you all for the pointers and ideas. Apologies on the slow reply, it’s been a busy few days with the holiday coming up.
I was worried about exactly that Brian. I know the wall load is barely anything and my walls are 2x6 so 4” of the wall is sitting on the joists anyways so that seems fine as you mentioned (yes, asphalt shingle).
Randy, I looked into a free standing deck. That looks like a trick to fit in there at only 4 feet wide.
I had an engineer advise me that it would be fine if I used Simpson hsql37s every 16 as they are shear transfers and that is well within distance specs since the rim joist is touching, but not fully on the foundation wall. Man are those things pricey!
Randy, the ties you showed the picture of were mentioned as well and I was told that they should not be needed if I used the above shear transfers but to use them if it made me feel better. My thinking is that they make me feel better and are cheap insurance.
I believe he is referring to the arrow area here. It looks like an error in the modeling of the graphic, as one would almost always have the top of the joist line up with the top of the ledger. The person doing the modeling needs to raise the joist hanger, as the bottom of the hanger was probably aligned to the bottom of the ledger. That or use taller joists in the model. (I used to do 3D solid modeling for a living).
