Avoiding joist hangers?
Tiziano
| Posted in General Questions on
I’m working on a 12′ x 16′ floor assembly which will rest on 6 helical piers (3 on each long side). The plan calls for 2×12 rims and joists, 24″ o.c., sheathed top and bottom, insulated with rigid and Rockwool batts.
Can I avoid joist hangers by adding a treated 2×6 (laying flat) between the pier L-brackets and the assembly? The idea is to rely on both end-nailing the joists and making use of the 2 1/2 ledge provided by the 2×6.
Or maybe a 2×4 instead, which would give me a 1 1/2″ ledge?
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Replies
Tiziano,
You can’t use the detail you have posted as the 2"x6” that the joist bears on is unsupported. I’m not to sure that’s a buildable detail anyway. How would you sequence the framing so that the sheathing on the underside was attached to the 2”x6” before the joists were installed?
The traditional method before joist-hangers was to add a 2”x2” ledger to the side of the flush beams to sit the joists on. It was still allowed in our code until maybe a decade ago. I don’t know if it still is. No one does it.
What problem are you trying to solve by avoiding joist-hangers?
This was the plan, minus the external beams:
https://www.finehomebuilding.com/project-guides/insulation/air-sealed-and-on-piers
My joists are 2x12 and I could not find 2x12 top flange hangers. Simpson's are only 11 1/8" deep and so the top 1/8" of the joist would be above the rims. Can't have that due to the subfloor sheeting going across to the second ply of the 2-ply rims.
That's not permitted under the IRC, which most locations use as the basis for their code: https://codes.iccsafe.org/content/IRC2021P1/chapter-5-floors#IRC2021P1_Pt03_Ch05_SecR502.6. I checked back to the 2015 code cycle and the same was true then.
Thanks.
I must have misunderstood this part of that IRC section: "Alternatively, the ends of joists shall be supported on a 1-inch by 4-inch (25 mm by 102 mm) ribbon strip and shall be nailed to the adjacent stud."
Looks like I'll need hangers then. These will do, assuming they're fine without a top flange.
https://www.strongtie.com/facemounthangersssl_solidsawnlumberconnector/lus_hanger/p/lus
Tizano,
Those work well and are available everywhere. Top flange bearing hangers are usually used when there is no beam to fasten to - like on a concrete wall with a sill -plate.
Excellent! I was concerned about the thickness of the steel at the bottom as well, but I just picked one up at Lowes an hour ago and it looks to be slightly less than 1/16". Not enough to worry about I think.
Thanks.
All the joist hangers look flimsy, but they're all engineered and tested to handle the loads they are rated for. No need to worry here :-) Do be sure to use the specified fasteners though, you can NOT cheat on those.
Bill
Thanks Bill.
Going with SD9112 2 1/2" screws per their chart.
4 into the joist and 8 into the rim.