Mid-span flush beam joist tension ties
Nifelheim
| Posted in Construction Techniques on
I have a mid span 3 ply LVL flush beam that joist hangers will be fastened to on either side. The joists are 2×12 SYP the other ends of the joists will be sitting on 2×6 exterior walls.
Question:
How do I strap the joists to tie them together so I’m maintaining control of outward thrusts on the exterior walls?
I don’t want the joists/hanger pulling out of the beam.
I do plan on straddling the beam with 3/4” subfloor which will sort of tie the two floor sections together at beam, however I would like to produce the same strength as with a lapped joists config with this flush beam/joist hanger config.
I can produce a sketch if needed.
Thanks.
Replies
Unless this floor is directly under a non-beam-supported roof, there should not be large loads trying to move the walls away from the center beam.
You can quantify the force that your 3/4 subfloor can withstand in the direction you are worried about and supplement fastener schedule to improve if you like.
The primary forces involved should be in the vertical direction.
Use of screws to attach the joist hangers to the beam can increase the ability to transfer loads in the direction you are concerned with. Joist hanger selection, and specification of the fasteners can help with your concerns.
You also would want to understand the ability of the beam to support screws in the side direction.
Tension ties that use a steel rod to transfer force from the opposing floor joists through or over/under the beam are also available.
The selection of framing components should be done in response to an understanding of the forces they need to handle, not comparison with another method.
If, however, you do want this assurance, start with the joist overlap and fastening schedule between those overlapping joists as a point of reference.
This alone should cover your concerns:
"I do plan on straddling the beam with 3/4” subfloor which will sort of tie the two floor sections together at beam, however I would like to produce the same strength as with a lapped joists config with this flush beam/joist hanger config."
Straddle the LVL beam (24" each side), glue & screw generously.
Attach your joist hangers to the LVL with hanger mfgr recommended screws.
Call it a day.