Help Calculating Ledger Connection

[stilllearningPE]

I am trying to add a 12'x36' raised deck to attached to my home with a ledger on one side and 4 posts on the other about 10 feet high. I can stamp the plans myself because I am licensed PE in Ca but am hesitant to do so because I don't fully understand the ledger to rim joist connection. The vertical loads I am concerned with are DL, LL, and uplift from W. I am assuming it is fixed joint connection and so will develop a moment. Dividing the moment by the lag screws spacing will give me the tension loads that need to be resisted in withdrawal. How would I calculate the moment since part of the deck is support by posts? Am I correct in my thinking or would this be a pined joint, and if so how would I calculate the withdrawal on the lag screws without a moment. I am having trouble conceptually and would appreciate any help to make sense of it. Thx

 

[TRAK.Structural]

Sounds like this is typical wood deck construction, in which case I think your ledger connection is just a pinned support. You would just need to calculate the shear capacity of the fasteners.

Not sure about residential code in California, but in my area this is a prescriptive detail from the code that doesn't even require engineering...

 

[Greenalleycat]

I would normally treat that detail as pinned so you'd have a simply supported beam between the post and the ledger
However, the devil is in the detail with this
You are presumably putting this ledger up against your cladding and bolting through which:
1) potentially compromises your waterproofing/cladding
2) puts an eccentricity in the bolt as the ledger will be offset from the rim joist - this can cause rotation and cladding crushing. I've been involved with a settlement on a house (not my design thankfully) that had this exact issue (see photo)

The good news is that, as Trak said, there are usually standard details for this in your local building code - but make sure that it applies to your cladding system

 

[SE2607]

To evaluate the lag bolt attaching the ledger to the existing structure, look at NDS's Technical Report No. 12 which gives modified equations for a gap between the two structural elements. Also ensure the lags occur at the existing studs, presumably @ 16", but should be field located prior to installation.

There is no standard detail for use in California that I am aware of.