Proper Method of Beam to Colum for two story column?
I’ll try to help. There are several issues.
First, I don’t think the posts have to extend two stories. I think the posts could extend from a foundation support up to the deck structural system.
Second, posts could extend from the deck structural system up to the roof overhang if necessary for the guardrail support. (The posts could align with the first floor posts, if necessary.)
Third, the size of the deck support beam (you call it a “rim joist”) is dependent on how far the deck extends from the wall AND how far it spans from post to post. By Code, “decks” are required to support 40 lbs. per square foot (psf). See Table R301.5)
If the exterior balcony is more than 6’ deep (I’ll assume 6’ you tell me if I’m wrong) and posts are more than 6’ apart, a single 2 x 6 will not provide enough support. In fact, 2-2 x 6’s will not give enough support.
Fourth, notching a 6 x 6 about 3” is excessive and will not give adequate support for the deck and guardrail.
I would restructure the balcony so that an adequate sized beam is used (4 x 8) and so that it is placed on top of a post, rather than notched into a 6 x 6.
Please note that the code requires decks to be anchored to the house in at least two locations using straps like this tie:
https://www.fastenersplus.com/products/Simpson-DTT2Z-Deck-Tension-Tie-Zmax-Finish?gclid=Cj0KCQjw7YblBRDFARIsAKkK-dJZrRsiFDrb6UevCNA1fWsgoBllbcaFbSIxYM08Q-lVaduQDD0EbOYaAvekEALw_wcB
I’d use a steel post cap (like Simpson Strong-Tie) to connect the beam to the post, but there isn’t enough info to size the connector.