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Question on residential floor joists connection from a non-structural engineer

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mbmsv

Electrical
Apr 21, 2016
2
Hello colleagues,

I am hoping I am not violating the code of this forum too badly. I was in the process of closing a deal on a house when I found a nasty problem with the way the builder framed the floor in two rooms where it is lowered by about 3" compared to the rest of the house. Here is a picture that demonstrates the problem:

Floor_joist_problem_xknxko.png


The joists I believe are 2x8 and spaced at 16". In most places they don't even touch the piece of wood, which runs under them but are rather simply hanging held by the two nails and thin air. I need to decide very quickly whether this can be fixed. So, I've come up with an idea of using Simpson front-mount joist hangers. The problem is they are not designed for two connecting pieces shifted relative to one another. However, I believe I can use a hanger designed for 2x10 or 2x12 and it will work. Could you please confirm or denounce this? Also, what the load capacity of each connection should be? I know that the residential floor live load capacity should be 40 psf or 200 kPa but how do I convert that into the required load capacity of a single joist hanger and by how much should I derate it considering that the joist is shifted relative to the header?

Here is a link to the Simpson load tables:

I think I would need to use on of the following hangers: HU210, HUS210, HU212, or HU214.

Thanks,
/Mikhail
 
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I don't like how the steel beam is being loaded eccentrically, but, as far as tying the top wood beam to the floor joists, I think one of Simpsons' brackets will get you enough nails in to transfer the joist load. Joist load will be your span length / 2 x 1.333 x (40 +10) - the 10 psf is my guess for your dead load.
 
Thanks a lot! That's exactly what I needed to know. The I-beam is loaded on the other side as well, I simply haven't shown it. Thanks again.
 
I'd recommend using the Simpson screws, rather than the nails. Better bite, better tension strength. Over time (for several dozen screws), it's easier to screw in the screws than swing a hammer in a tight space between joists.
Use a variable speed drill with a long nbr 2 screwdriver bit.
 
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