Elevated slab (light weight fill on metal deck) connection to CMU wall

[msdengineer]

I have seen various details for the connection of an elevated slab to a CMU load bearing wall. Some details show a connection of a "pour stop" steel angle bolted directly to the wall while others show a steel angle welded to the top of joists and an expansion joint at the wall. When do you attempt to isolate the floor system from the wall vs. directly attaching to the wall?

In the case of joists spanning parallel to the wall, I have seen steel angles also attached to the wall vs. placing another joist directly adjacent to the wall with a steel angle welded to the top with expansion joint.

Just looking for some theory or guidance as to when each situation applies. Thanks.

 

[a2mfk]

Always used angles, never have even seen the other details you are talking about. Usually the purpose of the angle is for gravity support of the deck and/or shear diaphragm transfer into the wall. Joists next to walls are a waste of a joist unless the owner specifically wants it because of future expansion or some other reason, plus you have potential for deflection incompatibility between two adjacent joists.

An expansion joint would not work if it was welded to joists that were connected to the walls, but maybe I am not understanding this detail...

 

[nuche1973]

Steel angles on the deck are easier (cheaper) to install in the field. I've seen the bolt on the wall stuff, when the building was being demo'd. It looked odd.

There are days when I wake up feeling like the dumbest man on the planet, then there are days when I confirm it.