Exposed Exterior I-Beam

[Sweeney]

Hi All, 

 

Not necessarily a software related question, more of a detail question. I am designing a pool house with a large roof overhang. The client would like to expose the steel I-beams being used to support the rafters. Wondering if any of you have details you are willing to share of I-beam to rafter connections? How to properly flash wall above steel? Run the SPF top plate thru and bolt to the beam? Anything is appreciated.

 

Cheers,

 

Austin 

 

 

[RGWhite]

Generally the I beam would be drilled with holes to accept the wood so as to bolt the two. Number and size of holes to be determined by the uplift.  Are you trying to design a moment frame?  As far as flashing, it appears from the picture you posted that it (framing) is tight under the roof overhang.

[rlackore]

You're bearing wood on steel? The easiest method is to attach a wood bearing plate to the top of the steel (I believe you have this shown). The plate-to-steel connection depends on 1) uplift (maybe seismic?), 2) thickness of beam top flange, and 3) thickness of bearing plate. If the top flange isn't too beefy, you may be able to use self-drilling screws; otherwise you're stuck with bolts or stud anchors. Fabricators are used to drilling bolt holes on either side of the web, typically at 24" oc; but, again, you need to verify the size/spacing for the expected forces.I would be just as concerned with the design in regard to thermal bridging at the beam/exterior wall interface - but maybe you've got that covered. FWIW, I sometimes prefer S-shapes (rails) over W-shapes for exterior exposed applications - the aggressive slope on the S-shape flange helps drainage and deters nesting birds. Plus, if you're not familiar with the standards for Architecturally Exposed Structural Steel, check out AESS Code of Standard Practice at AISC.org.

[Kbird1]

Wouldn't it be better to slide the bolted bearing plate forward so the sheathing is in-line with the Steel flange and have the Siding/Trim hang past the top flange  (1" ?) to help eliminate water penetration , even if it is  protected by the overhang in some areas ....better to have the detail consistent around the building.

[Jay_on_Cape]

We always use PT plates in contact with steel as the steel will induce condensation.  I'd run the plate flush with the edge of flange and run an "L" up the face of the PT and under the steel flange.  Whatever siding you use attache it to the flashing in a bed of sealant.

[ACADuser]

Some nice illistrations  https://www.openjoisttriforce.com/wood-to-steel-connections-making-sure-its-done-right/

I use Hilti fasteners most of the time but have also used welded Simpson hangers ILO bearing plate.