Expert: Bruce E. Johnson - 9/27/2010

Question
QUESTION: I'm searching for an detail of a truss support ledger that is welded to the wall structure instead of fastened with an anchor bolt. Is there a good reason why I cannot find an example detail where this type of system is used? Are ledgers ever welded to wall structures? It seems to me that a welded ledger would have the same integrity (if not better) as an anchor-bolted ledger.

ANSWER: Hi Cameron, I have seen welded ledgers used for steel trusses more commonly than wood trusses.  I suppose it is because of the different materials involved.  Obviously it is easier to bolt a wood ledger to a wall and fasten trusses to it using nails and H-clips or truss anchors.  However if you are a welder and prefer to do a steel ledger it wouldn't be unheard of.  The ledger could be an angle bolted to the wall in a similar fashion or embeds could be poured into the concrete and the ledger could be welded to the embeds.  As far as finding a detail goes you probably would have to have an engineer design a connection for you based on your desires.  I am attaching a simple drawing of an embed/ledger design I have used before, but the actual steel sizes etc. would have to be specified by a structural engineer to suit your needs.  I hope this information helps, please feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com

I'm sorry, I forgot to attach the drawing and for some reason this particular web page won't let me.  Please write back and I will be able to attach the drawing at that time.  Thank you and sorry for the inconvenience.  bej

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QUESTION: Thanks, Bruce. I would like to see the detail if you can still get it to me.

Answer
Hi Cameron, here is your detail.  And this is just one method but I think you can get a good idea how it's done.  The spacing of the embeds in the concrete depends on the thickness of the angle but it is generally every four feet with a 1/4" angle..the embeds are 3/8-1/2" plate with nominal embed studs welded to the back of them to lock them into the concrete.  The plates vary in size but generally speaking a 6"x6" face plate with one stud would suffice in this application.  I hope this information helps, please feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com