Sistering Deck Joists

[Umma Gumma]

I’m building a deck that’s 24x22 with two beams spaced 10 feet apart (2x10 construction, 12”OC). I hope to cantilever 2 feet past outer beam. There are two rows of five 6x6 posts about 6’ apart. Might be overkill but that’s okay.

22’ boards for joists are difficult to find at a reasonable cost. I’ like to sister the joists to get the full 22’ span.

My questions is what is the best way to sister the joists? I’ve seen it done two ways: 1. Where the joists overlap for some length over a beam and are connected together, and 2. Where the joists butt to each other over a beam and then another length of 2x10 is bolted on to cover the point where they meet and extends a few feet either way. I plan to vycore the tops of the joists where they sister together, as well as the tops of the beams.

I had discussed with the building inspector the idea of using a 12’ board and a 14’ board and overlapping 4’ over the first beam, and he was fine with that. Based on further reading, I’m wondering if this is better (stronger) than butting the boards over the beam (10’ and 12’ boards) and using a 3rd section 4-6 ft long for sistering. Any advice? Should I nail or bolt, and how many are required? I was thinking two bolts for each foot of sistering, and nailing or screwing in-between the bolts.

For the rim joists, would #2 above be the best approach?

Thanks for any help.

[Surface Tension]

1 and use 3' deck screws.

Double the rim joists. Butt the inner and 45 the outer.

Use blocking along the perimeter. That'll take out the bounce and a better mount of the railing.