Burying Steel Beams in Wood Stud Wall Volumes 7

[KootK]

I've got an architect wanting to hide some 30' steel beams inside a 2x6 stud wall system. This tends to restrict the pool off off the shelf W-beams that would be workable.

In what can only be described as an egregious tactical blunder, I mouthed off that even a 5.5" beam flange cannot be hidden in a 2x6 stud wall cavity unless one is willing to allow the walls to move to suit the in place beam locations when one considers tolerance issues such as permissible column misplacement and lateral beam sweep.

In response, the architect would now like me to stick to 4" wide beams to allow for the tolerances that I mentioned. So, yeah, that did not go as planned. Many of the beams would wind up having to be custom fabricated sections which would likely wind up having even worse sweep than rolled beams as a result of the welding heat introduced.

My question is this: is the normal thing to do in these situations to allow the beams to be 5.5" wide and just adapt the architectural system locations to suit? Put the walls wherever the beams wind up laterally? I feel that is indeed the case but I'm not positive.

 

[HouseBoy]

All,
Something still seems very much "off" with this post.
Among other things - Perhaps related to the issue of "bottom flange sweep":
I'm trying to sort out how the bottom flange will resist horizontal forces (perpendicular to the wall). We recently had a post asking about a blocking detail that is used to anchor the top of a framed wall that is built parallel to the floor joists. Seems like we have the same issue here.
Two nails might be capable of resisting 100+lbs but... WHAT is restraining WHAT? The top of the wall is dependent on the beam for horizontal restraint. Seems like even if we can restrain the top flange (and we have web stiffeners) the perpendicular force at the top of the wall (creating load on the bottom flange) will have leverage over the beam that will cause torsional type rotation.

Naturally much will depend on the precise details (span, wall height, exposure, etc.)
Gotta wonder what this question is (really) all about.....

 

[JoshPlumSE]

What about HSS? You can get up to an HSS16x4x5/8. With a top and bottom nailer, drywall is still reasonable, tolerances are likely better than a custom fab job, and the price shouldn't be too much worse.

I have to say that I was thinking something along these lines as well.

 

[kissymoose]

It's been 2.5 weeks since Koot's logged on. Is anyone in contact with him off site and can confirm his wellbeing?

 

[jayrod12]

I've spoken with him as recently as today. He's alive and well.

 

[kissymoose]

Alright, thanks.

 

[JLNJ]

He's hanging out with Ja Morant and decided to go dark for a while.

 

[KootK]

I'm jumping back in here for a) closure b) to answer asked questions and c) to let folks now that the rumors of my demise have been greatly exaggerated.

I've been guilty of poorly servicing my own thread on this one. I had what I needed to move forward a few hours in and then was too busy to keep up with the conversation properly. My bad.

 

[KootK]

It will be useful for me to provide some additional context before proceeding as this will be necessary to answer a bunch of the questions asked. I'll also described the end result.

Thanks to all for your assistance with this. I am very grateful that, when I'm in a pinch, I tend to get all of the king's horses and all of the king's men, so to speak. It is a testament to the generosity of spirit that pervades this community.

This is a high low condition at a roof step. The low beam will do all of the work and needs to clear span. The upper beam will be much small and is to be supported on 1/3 point 3x3 HSS posts in the clearstory window system above. Two of the options initially proposed are shown below (welded WF and off the shelf WF). This should illustrate the flavor of the thing.

Initially, the architect chose the welded WF beam solution. Later, in the process of trying to figure out why our models did not match, I discovered that they had made the wall system at the clearstory 2x8, similar to XR250's suggestion. So we went back to an off the shelf WF. In the end, the architect decided that they wanted the 2x8 system for their own, thermal performance issues.

Note to self: always attempt to persuade by speaking to others problems rather than self's own. Sales 101..

 

[KootK]

What about HSS?

It was an option. How do we feel about plate fastening to HSS though? I know that it can be done with some kind of shot in fastener but, in general, we prefer fasteners through predrilled holes in flanges, do we not?

..what precluded you from making the beam multi-span within the 2x6 wall?

As shown above, it's only a wall system above the beam.

Not sure on the situation here but could you get a story deep truss to work instead of the 30" beams?

The thing almost has that form with the high and low beam / clearstorey situation. I'd considered using both beams vierendeel style but the posts need to be very small and the upper beam very shallow. So the truss behavior was dwarfed by the raw stiffness of the lower, large beam.

Is it just the bottom flange that is a restricted width?

I could have done the reverse: a narrow top flange and a wide, off center bottom flange.

Might need a square tube at the bottom flange just to deal with that...

Being a high low condition, which you had no way of knowing a priori:

1) No wind to the bottom flange and;

2) Bottom flange braced if I'd wanted it to be.

It is bike season. I suspect our chatty fella is balancing all his interests.

Correct. Short Canadian summer = dog, bikes, health.

Here's a fun pic of my bestie and his, somewhat cowardly, bestie facing off against a giant, pre-historic mega-doodle.

I've also got a neat new build bike in the stable that was chosen for it's structural steel material significance (Reynolds 853). See, I live. A little.

 

[phamENG]

It was an option. How do we feel about plate fastening to HSS though? I know that it can be done with some kind of shot in fastener but, in general, we prefer fasteners through predrilled holes in flanges, do we not?

Meh. I'm okay with pins as long as they use the right ones. If the walls of the HSS are thing enough, I'm okay with screws like Simpson's wood-to-steel screw that don't require predrilling.

 

[Craig_H]

Your otherwise watertight excuse of riding bikes has a giant leak called "lack of bar tape"
Good point about speaking the architect's language... I too occasionally try the shotgun approach by throwing out buzzwords like "vapour barrier continuity" and hoping something will stick ("stick" = let me avoid revising something for the eighth time).

 

[jerseyshore]

Have to make them think that they are making the decision. We all know how architects want that control. Since NJ changed to the 2021 codes in March and everyone is complaining about insulation. So I slide in on all these jobs now saying "2x4's what are you crazy, how are you going to make it work with the energy code". 60% of the time, works every time.

 

[KootK]

Your otherwise watertight excuse of riding bikes has a giant leak called "lack of bar tape"

Good eye. Presently, that bike is one of eight, with only four being rideable. I've contracted a wicked case of n+1 disease I'm afraid.

 

[dik]

Can you use a 2x8 wall?

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[KootK]

Can you use a 2x8 wall?

Indeed. Can, and have.

Initially, the architect chose the welded WF beam solution. Later, in the process of trying to figure out why our models did not match, I discovered that they had made the wall system at the clearstory 2x8, similar to XR250's suggestion. So we went back to an off the shelf WF. In the end, the architect decided that they wanted the 2x8 system for their own, thermal performance issues.