Best Practice for Splicing Deck Ledger and Rim Joist
Can anyone suggest what the best method is for handling joints in a deck ledger and rim joist?
I’m going to be a building a deck that is 14′ x 28′ (joists will be 14′) so there’s going to have to be some joints in the rim and ledger.
The ledger will be fastened to the concrete foundation and the other end of the joists will be cantilevered 1 foot over the beam so the rim joist is mainly to prevent rolling and help secure the guard rail post.
I plan to use the tension tie method of securing the guard posts explained here:
https://www.finehomebuilding.com/project-guides/decks/options-fastening-deck-guardrails
For the rim joist, I was thinking I could just have the joints land between two joists and then add some blocking between those joists and face screw the two ends of the rim into the blocking.
For the ledger, I was thinking of having the joint again land between two joists and then adding additional fasteners on either side of the joint to support it.
Greatly appreciate any advice anyone can offer.
-Patrick
Replies
Your plan for the ledger is fine. For the rim, just splice over the end of a joist using a lap or a scarf joint. I'd prefer the lap. You could make it 16" long and hit two joists.
Thanks for the reply. I'm a newb so I had to look those joints up. Seems like the lap joint would be easier. I guess the usual technique for cutting those would be to set a circular saw to a 3/4" depth and make multiple cuts along the 16" lap then chisel them out?
Then I guess use fasteners plus construction adhesive to make the connection (e.g., 2 rows of fasteners spaced 6" O.C.), leaving 3" space between the first set of fasteners and the end grain of each piece?
Grateful for any additional tips.
-Patrick
I've built more decks and floors than I can count and the only way I've done it is to break them on a joist.
I guess you'd just two sets of nails in the break joist then? I'm a bit concerned that the end grain of the joist my get pretty chewed up with that many nails and years of wood movement.
I think I'd be inclined to add blocking on either side of the break joist and fasten the rim to the blocks as well. The rim won't take a huge amount of load because of the cantilever, but we have a bit of a view so I imagine people will sometimes feel the urge to stand right up against the rail.
Have it your way, I've only been doing it for 50 years. Lol! It's your job and it won't hurt to add scabs but it's not necessary either. Have you watched the Larry Haun framing videos? They are good videos and if you watch you'll see that he doesn't even land joints on a joist.
https://www.youtube.com/watch?v=yh6cMQnWGwA
You're right. I have no experience doing this. And I respect your experience. Your response is what made me reconsider my original idea of fastening the break to blocking.
Also, thanks for the pointer to Larry's videos...I'll take a look at those.
I agree, it's probably not strictly necessary, but, because it's my own house, I like to lean towards making things stronger.
Perhaps it's a bit obsessive, but I also care about the aesthetics of my framing...even if nobody but me will ever see it. On that score, I feel like I will almost certainly end up with the sharp end of a few nails popping out of the joist if I try to nail to only half the end grain...I'm just not that good at aiming my nail gun.
We're going downhill here! LOl! I'm just pointing that if you're building your own house there is no need to spend time or money doing things that won't improve the structure. But, I'm anal about lots of details myself so do it however. There's really no wrong way.
With a lap or scarf joint you only use one set of nails.
The scarf doesn't really need any nails at all to hold the two pieces together right? ...I'm thinking of the method here:
https://www.youtube.com/watch?v=-SUtoKKNKHQ
So you would just nail into the joist as the rim was a single continuous board right?
Lap joint seems like it wouldn't have the same strength as the scarf joint unless you added more fasteners to the joint (say 6" o.c. over the length of the lap). When I was thinking about how to do the lap joint, I was leaning towards using construction adhesive, which would probably work really well given the large surface area. Then you wouldn't need the nails for strength, they'd just hold the joint together until the glue dries.
I came across another idea for the rim joist: scab a block onto the joist where the joint occurs (so the end of the block and the end of the joist are flush) and fasten one section of the rim to the end grain of the scabbed block and the other to the joist.
That way you're not putting so many fasteners into one joist and the fasteners can be driven into the middle of the end grain and a bit further away from the ends of the two rim joist pieces.
What does everyone think about that idea?