Connecting Wooden Rafters to Steel Tube Ridge Beam

[bridgebuster]

I'm designing a portico - see attachment - the roof framing will be timber. However, the ridge beam will be a steel HSS 10 x 4 x 5/16; spanning about 28 feet. The architect doesn't want any interior posts supporting it.

To connect the rafters to the ridge beam can I use a timber rafter hanger, such as a Simpson LRU, and design screws to attach it? Or is there some other product available for this application. Google isn't much help today.

Thanks

 

[msquared48]

Simpson used to have weldable hangers, but you ciuld also use a top plate of wood or side hung wood plates using Nelson sill plate anchors.

Mike McCann, PE, SE (WA)

 

[bridgebuster]

Thanks Mike; I knew I could rely on you! I was also thinking welding a pair of plates and thru-bolting the rafters.

 

[Ron]

Shoot standard Simpson rafter hangers into the side of the HSS using PAF's.

 

[bridgebuster]

Thanks Ron; another guy who can always be counted on.

 

[jayrod12]

There's also the hollo-bolt style anchors for fastening stuff to steel. Specifically HSS. Search for lindapter. I would use them or something equivalent to that to fasten a wood nailer/ledger and then use standard wood hangers.

 

[bridgebuster]

Good idea, I didn't think about blind bolts.

 

[hokie66]

But if you are going to bolt on a ledger, why not just use through bolts?

 

[bridgebuster]

Actually, it's a moot point now. At the last minute the powers that be decided the rafters would look nicer sitting on the top of the ridge beam.

 

[msquared48]

Still will need a wood nailer on top.

Mike McCann, PE, SE (WA)

 

[jdgengineer]

Do others use through bolts on HSS? I was under the impression you would need to provide a nut/washer inside the tube. We typically use threaded welded studs in these situations.

 

[bridgebuster]

Mike - the powers that be want a pair of keeper angles screwed to the tube and thru-bolts to hold the rafters.

 

[msquared48]

More complicated, but that will work too.

Mike McCann, PE, SE (WA)