Steel garage door header connection to wood

[Bammer25]

What would you guys expect to see connection wise for a steel beam bearing on a 2x4 stud wall for a garage header? I am sizing the beam (simple) but not 100 percent on mixing steel and wood. Is that a no-no?

Galvanized? Pressure treated wood only? Use steel posts to bring the load down to slab? Steel Base plate under bottom flange?

 

[Bammer25]

No ideas?

 

[jayrod12]

Patience good lad. We like to take our weekends off too.

This is done all the time. Usually it would be a plate on the bottom of the beam with bolts to the wall below. The concern I would see is providing torsional restraint at the beam end. Do you have a section through the wall that relates top of header to roof joist/truss?

 

[Bammer25]

I am unsure on whether or not roof trusses will bear directly on the beam (or I suppose a top plate attached to beam), but there may be a stud wall framing above the beam before the trusses. Still waiting on the plans

 

[Colostruct]

I use wood posts supporting steel all the time. Typically solid posts (solid wood, glulam or PSL) are used. An advantage is that the wood posts over a steel post is that the shear walls at the sides of the door can be easily nailed to a wood post. Typically, I use steel straps bolted to the sides of the posts.

A cripple wall (as we call them) on top of a beam of any type is not recommended since lateral stability of the beam is not possible. So, a bigger beam is required that has a longer unsupported length. Best to have the beam laterally supported by the joists and sheathing of the supported elements. In any case end restraint is required. But, if the entire beam is laterally supported the end restraint can be pretty easily accomplished (I often extend a double king stud within the wall fastened to the column that engages the wall plate). Sometimes, if the load is heavy, bracing may be required.

My first thought is that if there is enough room for a cripple wall above the beam I would think there might be enough room for a deeper glulam?

In general, wood and steel can co exist just fine but the rules of stability and restraint still apply.

 

[Bammer25]

Thanks. Just wanted to make sure I wasn’t mixing and matching correctly.

 

[XR250]

In my area, this is done all the time without any concern for top flange stability (cripple wall) or connection to the studs. I generally only specify the bolted nailers on top. Have never seen a problem in my 30 years of practice.

 

[Bammer25]

So you typically have holes drilled on the bottom flange and use bolts or some type of Simpson connectors?

Do you mate a top chord timber to the top flange so you can have wood on wood connections for the trusses or rafters above?

 

[Colostruct]

I use a 2 x “nailer” thru bolted to the top flange. If the hurricane clips require more load, I use a double plate or LVL. Usually, 1/2” bolts @ 16” O.C. Net spacing staggered each flange.

Supports I use 1/4” side tabs with thru bolts or structural 1/4” screws.

XR250. The AISC provides different allowable moments based on the unsupported lengths of the compression flange. So, if the beam is undersized...a lot...you don’t have to provide top flange restraint. But, beam ends need to be restrained in some manner regardless.

 

[Bammer25]

Roof trusses or floor trusses at 24” OC certainly count for bracing the compression flange. Seems to be lateral torsional buckling would not be an issue.

 

[Colostruct]

Bammer25

For the load that is likely being supported I agree that the trusses will provide an unsupported length that will be short enough that the “full” bending moment can be used.

But, an infill wall may not provide the restraint due to the “hinge” it creates.

Torsion is, likely not an issue if the loads are not offset.

 

[XR250]

XR250. The AISC provides different allowable moments based on the unsupported lengths of the compression flange. So, if the beam is undersized...a lot...you don’t have to provide top flange restraint. But, beam ends need to be restrained in some manner regardless.

Yes, I am familiar with that.

 

[Bammer25]

No need for galvanized or painted since these walls should not be pressure treated?