Slip Detail for Interior Non-Load Brg Partitions

[JAE]

I've got a large wood framed (one story) building that is framed with load-bearing wood stud walls and shearwalls that support combinations of wood trusses (pre-engineered) and steel beams.

In most cases, the steel wide flange beams support the wood trusses.

At issue is what to do with a multitude of interior non-load bearing wood stud walls that want to frame up to the bottom of the wood trusses. We are trying to establish our design criteria for the steel beams where we want to keep the vertical deflection under control.

We are using L/360 for the roof snow load as one limit to never exceed.

We also are using 1/2" as an absolute limit for steel beam deflection to ensure that we don't damage partitions below. This is resulting in some very large beams controlled by this deflection.

But we are thinking that maybe we could go higher than 1/2" if we provide some kind of slip connection at the juncture of the partition to the bottom of the truss. Metal studs have those slip tracks that can be used...but in wood - are there any details out there that address this. The partitions sit on the concrete slab below so there is no give should the truss try to bear on the partition.

 

[UcfSE]

An alternate detail to the slip track is a clip with vertically slotted holes for screws and probably some teflon washers or inserts. When I design this detail for metal studs I typically use this connection since the slip track tends to get large (heavy gauge) very quickly. Instead of using a propietary clip, like the Verticlip made by The Steel Network, occasionally I give them a generic call-out for a clip angle with slotted holes. Most of the time I just use the Verticlip. Typical range for these clips is a 2 inch vertically slotted hole to accomodate +/- 0.75 inches up or down deflection. You might be able to adopt this to your wood studs easier than a slip track. Typical size is L2"x3.5" LLV x the thickness you need x (stud depth -0.5") long. That may or may not need to be increased for your connectors since that size is for steel framing. There are similar things you can do if the walls are not right under the beam but off to one side. As a guide I look at The Steel Network's details on their website to get some ideas for how to connect for slip.

http://www.steelnetwork.com/steel_framing_products.asp

Some can probably be adapted pretty easily for use with wood wall instead of metal framing.

 

[JAE]

UcfSE - note that my situation is with WOOD studs, not metal.

 

[UcfSE]

I did note that. My point was that yes I believe you can allow more than 1/2" deflection in your beam since other connectors, for METAL STUDS, allow you +/- 0.75". You just need to take that into account when you engineer your clip. I think you could ADAPT a connector, similar to the metal stud connector, for use with WOOD. You will just have to design for different connector capacities and spacing/edge distance requirements. I sent you a link to a metal stud site because it shows connections in different situations since you did not specify one, i.e. directly under a beam flange or off to one side, etc. You can pick your own configuration or adapt what others have done to meet your needs. That is why I wrote " you might be able to ADAPT this to your WOOD studs". I don't know of any deflection clips manfactured for WOOD so I was suggesting you design your own clip with some slotted holes and wood screws in a similar manner to those that have been done for metal studs.

That's where I would start with it.

 

[JAE]

ok - thanks for the reply (sorry I didn't see your reference to wood...need to read more s l o w l y)

thanks again.

 

[UcfSE]

Hey anytime I can help out JAE, I know you are very knowledgeable from your posts and it's nice for a youngin like me to have a chance to help out a senior member, if indeed I get to do that.

 

[whyun]

JAE,

I've read through the thread very quickly so my solution may not be the one you are looking for...

If you are looking for a deflection controlled slip connection between your wood truss bottom to your interior wood partition, Simpson makes Roof Truss Clips for this purpose. Model numbers are STC, STCT and DTC. They do come with vertical slots UcfSE is talking about. Note that the "gap" recommended is 1/4" which is not a whole lot.

 

[JAE]

Thanks to you two - appreciate it.

 

[jheidt2543]

I've seen a detail using steel angles each side of a masonry wall. You could adapt it for wood stud walls using either clip angles at trusses perpendicular to the wall or continous angles directly under the truss. I also think you could use heavy gage metal angle rather than a rolled steel section. The wall would have lateral support without being attached to the deflecting truss and you could pick the amount of movement allowed. Movement of 1/4" seems too little to me, I'm thinking more like 1/2" depending on truss span of course.

Just another thought!