Torsion Box Webbing

[Craig Earls]

I understand the the entire purpose of the torsion box webbing is to transmit shear to the opposite skin. That said, it seems the best possible webbing would be real wood oriented with the grain in the direction of the webbing so the the glue joint wasn't on an end grain.

If you use plywood, OSB, or MDF how much do you sacrifice by not having the same shear strength in the glue joint?

[Todd Burch]

I guess it depends.

If what you are building is overkill in the first place, then you sacrifice nothing.

I've built torsion boxes with 1/4" ply as the webbing for 1/4" ply outer skins. It worked just fine edge gluing the web to the skin.

I probably wouldn't use OSB as interior webbing unless I encased it within grooved sticks, to form what is best described as an residential home interior joist I-beam.

MDF would just be too heavy. Interior doors are made with cardboard webbing.

Todd

[John Shuk]

I know a guy who makes captain's beds and uses 1/2 osb. Having seen it firsthand it seems really stout.