Top Mounted Hangers Against Fire Rated Plywood, Do Studs And Joists Need To Line Up?

personalt

I have a three family project where I need to hang to joists off the top of the steel wall rather then pass over the wall.. at the top of the wall I have firerated plywood that the bacl of the top mounted hangers rest againt. has anyone built a wall like that? I am wondering if the plywood will provide enough support or do my joists need to line up with the studs. I have a call into the engineer but he is on vacation this week.

mdshunk

Yes, that is a question for an engineer, but it begs a question from me. Why wouldn't you just frame that wall shorter and set the joists on top of it?

personalt

it has to do with the fire rating. the exterior and load bearing walls need to be continous steel. with double 5/8 sheetrock. the joists can't be on top because in a fire they will burn and floor above will collapse. for interior walls I could go over studs if I added squash blocks but outside must be hung from top of steel. I will have to get ahold of engineers assistant as this is not a common design.