Cross-Grain Bending in wood members, Ledger 2

[redtiger]

Hello,

I am designing a wood structure that has a 3'-6" parapet. Im using a 2x ledger to support a top mounted hanger that ultimately suppors the joist. A 2x blocking is provided to transfer the diaphragm shear into the shearwall.

Should I consider cross grain bending, I am not using bolts, and the out of plane forces for an 8ft high are minimum. Wind governs at 16 psf.

Thank you.

 

[PittEng88]

Why not just provide a dbl. top plate for your joists to bear on and a 2x rim board for you to attach your plywood diaphragm to?

 

[XR250]

Cross grain bending in the ledger? The H8 should take the out-of-plane load. I might put them 16" O.C. and put a note to position the joists so that the
H8 can be attached to both the joist and stud. I would also run the sheathing along the back of the parapet to give the shear another load path.
You might want to check your parapet loads. My money is on wind pressure greater than 16 psf.

 

[redtiger]

PittEng88,

I can do that, but my concern is attaching the parapet wall to the structure without using knee braces.

 

[redtiger]

XR250,

The h8 are at 16" on center and there is a note stating that the studs must align with the roof joist.

Regarding the sheating along the back of the parapet (the right side of the stud, per the sketch), I don't quite follow your shear load pad. Lets say that your diaphragm's shear at that ledger is 250 #/ft, you are transferring it into the continuous 2x blocking on the top the ledger and finally to the shear wall(left side of the stud, per sketch).

Regarding wind pressure, I will re-check the load.

Thank you guys.

 

[XR250]

Regarding the sheating along the back of the parapet (the right side of the stud, per the sketch), I don't quite follow your shear load pad. Lets say that your diaphragm's shear at that ledger is 250 #/ft, you are transferring it into the continuous 2x blocking on the top the ledger and finally to the shear wall(left side of the stud, per sketch).

The roof shear can also go up to the back of the parapet, across the plate and down into the the shearwall. Just another load path to take advantage of. You likely have to sheath it anyway so it is basically a free lunch. My guess is a 2x6 can cantilever 3'-6" without knee braces.