Top mounted timber joist hangers 5

[valeriepsuae85]

I have a project where the contractor did not install the 2x wood on top of a W8 girder, he used 3/4" plywood on top of the steel girder. The nails in the top of the hanger were placed in the predrilled holes but on an angle (like a toenail). I know Simpson has tested their top mounted timber joist hangers to be supported by a 2x on top of a steel member but I think the plywood can also hold the hanger in place. Is it reasonable to accept this type of installation?

 

[Ron]

Assuming you have symmetric joist locations and hanger locations on each beam are symmetric, then you could place a 12 to 14 gauge sheet metal "repair" plate across the top flange of two symmetric hangers and tie them together across the top of the beam and plywood. For fasteners, I would use powder actuated and drive them through the W8 flange. It would be better to use powder actuated deck fasteners as you can typically get better penetration with those. Standard powder actuated fasteners will work, but use high power loads.

If powder actuated fasteners are a problem, use Teks screws (self-drilling, self-tapping).

At the terminous where you do not have a corresponding hanger on the opposite side of the beam, just use a plate and put fasteners on both sides.

I believe these hangers are designed to develop some moment due to deflection of the joist, so the resulting force couple translates to shear in the fasteners. With the fasteners I have noted, that should not be a problem.

 

[valeriepsuae85]

ron, good idea and easy to install. I bet I could use a standard Simpson strap, no special fabrication would be needed.

 

[Ron]

Let us know how it works out...good luck.