2x6 frame walls brick veneered 1

[rittz]

Any tips on this situation? The contractor built a 2x6 stud wall (residential) 22 ft high unsupported except top and bottom, with intention to veneer it with face brick. The stud wall was built in two parts .... a 10 ft high section with double plate at top and then a 12 ft section from there up. use wind load 12 PSF

 

[JAE]

I don't see how this can even begin to work. A double top plate about half-way up is a "pin" in the wall so the wall has no lateral flexural ability to resist the wind at all.

You could try using some Simpson straps to create a through-moment connection from lower stud to upper stud (vertical straps on each face of each stud), but there would still be an increased flexibility in the stud assembly.

Are you sure about the wind load? Components and cladding for a residence in 90 mph wind zone is between 13.5 and 17 psf depending on the zone.

Also, a 2x6 stud spanning 22 feet just really doesn't work for stiffness. A 2x6, under 12 psf wind, will deflect about 1.5 inches (assuming DF No. 2). That is significantly more than L/360 and way more than L/600.

There's some debate as to whether L/360 would apply or L/600 (we use L/600) for brick veneer but your situation is way beyond that.

 

[rittz]

I couldn't agree more .... What about a horizonal WF beam at the hinge

 

[JAE]

Yes, any sort of horizontal "girt" might work - a built-up LVL or large wood beam would work also - presuming the span is manageable.

Just need to be sure to tie it into adjoining walls both for positive and negative wind pressure.

Check the deflection.

 

[csd72]

Dont forget that if you have any axial load on these then there will be second order effects from the deflection.

I had a similar situation once and I made the contractor rebuild it.

Only other option is steel straps front and back to provide full tension capacity past the horizontal plate.

Dont forget that cross grain compression capacity is less than along grain.

 

[enginerding]

How did they actually get this built? Is this a very small wall? If it is only a few feet wide, the double plate at the center can probably act as a beam spanning horizontally. If the wall is significantly wider, I wonder how they lifted a 12' tall wall up 10' to stack it on the lower wall - especially because the lower wall had to have braces extending back to keep it from toppling over...

 

[COEngineeer]

Is this around the stair well or an opening in a great room? If it is, it is a common noobie framer mistake. They should have baloon framed the wall. Also, it might also be part of engineer's fault for not specifying baloon framing at that location. Rut roh!

Never, but never question engineer's judgement

 

[msquared48]

I agree with JAE. This is a ridiculous structural situation. The contractor obviously does not understand structures. Don't put your but on the line here for aqnyone, appearance or otherwise. Do what is safe, particularly if this is a bearing wall too for the roof?

This reeks of c##$.

Mike McCann
MMC Engineering

 

[MiketheEngineer]

This is not acceptable unless you want to put in a floor

 

[DaveAtkins]

I normally try not to be melodramatic, but...

I would tell the contractor to stop work immediately. A wood framed building near where I live collapsed two years ago (during construction), injuring a worker. The reason for the collapse was never revealed, but I talked to someone who saw the wreckage and he suspected it was built the way you describe. One wall on top of another wall. Totally unstable.

DaveAtkins

 

[JAE]

Rut roh!

Heh.

COEngineeer - I love that quote. Seems like we get a bit of that here at ET, eh?

 

[rittz]

I have decided to have them change the wall to 2x8 @12" oc.(balloon framing). The wall is 21 ft high and 32 ft long. and is parallel with the roof trusses.... thus they need lateral support at the top of the wall (level with the bottom chord). (another hinge) We will work out some bracing in the truss systen to achieve the support. THanks for all the comments folks.

 

[COEngineeer]

You might want to specify LVLs. Easier to get straight studs that long, plus they are stronger.

Never, but never question engineer's judgement

 

[bigmig]

A tall wall design reference for those interested:

http://www.ilevel.com/literature/TJ-9004.pdf

 

[lkjh345]

bigmig:

Thanks for the link. Some interesting stuff.

 

[boo1]

dik posted a link at:

http://www.cwc.ca/NR/rdonlyres/5B2929DA-FF5F-4FC4-89D5-6C40CF33D2B6/0/TallWalls07E.pdf