Is it ever a common practice to put a joist hanger upside down? My architect wants me to put a double rim joist (2) 1.75″x9.5″ LVL at the end of my cantilevered floor because it’s a load bearing cantilevered wall. My thought is that the weight of the loaded wall will be pushing down on the rim(s) mostly (3.5″ of the 2×6 exterior wall) and the best way to transfer that load to the joists would be to put the hanger upside down. Most of the screws (or nails) are in the face of the hanger, and only about 3 on each side. This would in effect make a hanger where the rim (or beam) is bearing down on the joist, rather than a joist bearing down on a beam.
Is this ever done or a common practice when called for?
Jim
Replies
I’ve never seen it, and I don’t think Simpson designed their bracket to go upside down. I don’t understand what’s pushing up, gravity is pulling the load down usually.
So the failure you see these upside down joist hangers preventing would be the rim joist(s) shearing off of the joists because 3.5" of the 5.5" wall is bearing on the rim. So without the upside hangers, this would happen when the wall split. down the middle vertically including the bottom plate and the double top plate. But then the remaining 2" of wall that bears on the joists would still carry the load above. At this point the rim would carry no load at all and failure would stop. Somehow I don't see this happening.
I don't understand the need for a double rim, let alone LVLs since the joists themselves are carrying the load.
Not sure if this is helpful but I do know they did hang them upside down on a TOH episode because of a cantilevered roof. I would suggest contacting Simpson and asking just to make sure. Below is the episode. Check around the 3:20 mark.
https://youtu.be/cu5jJ7PtQso