Cold Formed Ledger Track

[RFreund]

Do you ever used a CFM Track as a ledger? Similar to joists framing into a CFM track but the track is bolted to a wall as a ledger board would be. You would then have connections at the top and bottom flanges of the track at each joist. Usually I suppose you would use a clip angle for this type of connection. I could run some numbers but I was curious if there was some sort of standard calc or how common this was.

Thanks.

EIT

http://www.HowToEngineer.com

 

[msquared48]

Don't want to throw you off track here, but I have never seen or used such a detail...yet.

I have see the track used as a rim joist on a bearing wall with the joists framing to it, but not a ledger. Seems like it could work if the loads were very, very light. With heavier loads you might use a steel angle for the ledger the track to sit on.

Remember that the track may also have to function as a diaphragm chord member unless there is some other available member to use.

Mike McCann
MMC Engineering

 

[RFreund]

Yeah, I don't use it either. Just curious.

I could check the track flange for bending, etc. It is similar to how the track acts when supporting a wall subject to wind load so I suppose I could used the same methodology as they do there.

EIT

http://www.HowToEngineer.com

 

[XR250]

I use them occasionally. AISIwin 8.0 (free download) gives vales for it (joist to track connection) but is limited to certain gages and depths.

 

[BUGGAR]

Track material is frequently made of material with a yield stress of 33 ksi instead of 50 ksi used for framing, depending upon the manufacturer. If that matters.

 

[EngineeringEric]

The track material is specified. If you only use 20ga then it will be 33 ksi. I have seen it used but it should only used load wise as an edge nailer and to tie the diaphragm into the wall. If you have any decent load you have to use a clip at each joist at which point the 'ledger' is not a typical ledger.

 

[brut3]

The Cold Formed Steel Engineers Institute CFSEI has a tech note for calculating the capacity of a deep leg deflection track, I would definitely check that out. Using this tech note could assume a conservative gap distance between the web of the ledger track and the web end of the joist member to calculate the capacity of a single bearing flange on the ledger track member. This should give you a conservative capacity as well since theoretically both flanges of the ledger track should be fastened to the joist member.

As stated from multiple people above this isn't a typical connection detail that you would see; however, I don't feel it is an unreasonable detail if the applied loads are within reason.

 

[RFreund]

Thanks guys !

EIT

http://www.HowToEngineer.com