Steel beam web infill with wood

[JStructsteel]

Contractor wants to do face hangers on infill inside the steel beam. Do you folks think a detail showing the wood bearing on the flange is required, otherwise the cross grain capacity isnt that good. I have some longer spans, and also some beams framing into the sides. At beam hangers, would possibly need to have web stiffeners too.

 

[dik]

I've used the detail lots of times, and it works without stiffeners. Bolts could be staggered at 2' o/c, ie. 2' between top and bottom bolts. Spacing may be close enough to cause shrinkage cracking in the infill lumber. Also any joists framing into the blocking should be 1/2 or more above the top of the steel beam. The joists may shrink and steel beam may be prominent on your floor plan.

 

[JStructsteel]

Thanks Dik. I was thinking web stiffeners to brace the flange actually at beams that are heavily loaded.

 

[ANE91]

I don’t like this detail. Contractor seems to have a bunch of Simpson hangers laying around and no welder or PDFs.

Wood has a tendency to shrink and check, and it can crack around fasteners. Best to use more smaller fasteners than fewer large ones.

Also, the NDS is pretty clear in 3.8.2 about avoiding cross-grain tension.

What about shooting a plate onto the top flange for a bearing connection with blocked ends?

 

[XR250]

I use this detail regularly.

 

[Eng16080]

I use this detail regularly

Same.

I would not be overly concerned with shrinkage considering the infill is supported on the bottom flange. A wood nailer on the top flange with top mount hangers can be a good alternative to this detail, but in many cases the additional depth isn't available. Also, I would often consider this detail as providing bottom bracing for the steel beam in the case that there's negative bending.

Where there are larger concentrated loads being supported by the steel beam, I almost always use web stiffeners.

 

[Taimoor957]

As others have mentioned, this detail is quite famous, one of drawback i found is the top row of nails will hit the steel for face mount hangers. With a shallower steel beam than the joist, will require the infill timber plate completely out of steel with no bearing from bottom flange of steel. If you are concerned about large reaction on bolts causing split due to tension perpendicular to grain, try exploring mitek I believe they have some solution.

 

[Eng16080]

one of drawback i found is the top row of nails will hit the steel for face mount hangers.

I understand the concern but have not run into this problem myself. If the top of wood joist happens to be flush with the top of steel or slightly above it, this interference will usually not occur with a typical face mount hanger which is often 2 or 3 inches shallower in height than the joist depth.

 

[JStructsteel]

The final detail will be that the steel beam has a nailer on top, and the joists flush with that, so the infill will be out past the edge of the flange. Nailing should not be an issue.

 

[jerseyshore]

I also use this detail almost daily and you always want to show the wood blocking bearing directly on the bottom flange.

9/10 times I use a 2x nailer on the top flange so the top nail holes in a typical LUS face mount hanger will be nailed into the side of the 2x nailer.

I've never used web stiffeners on a steel beam because of a wood beam connection. If the loading is that high you'll probably have a steel beam instead.

I did go to a job once where they specified web stiffeners below all of the steel columns the beam was picking up. The idiot house framer thought the beam stiffeners were "beam pockets" and smashed a bunch of flitch beams into the gaps between stiffeners. Was an absolute disaster and messed up the ends of almost a dozen flitch plates.