Spliced 2x4 Wall near staircase 3

[Brobocop]

Two 10ft tall 2x4 walls with double top plate, non-continuous stud framing adjacent to staircase. Wall span is 8ft wide.

I recognize this framing is a big no no, per the code and it was called out by the city inspector.

Should have probably gone with continuous 2x6 studs.

Is there a retrofit fix here, or is it just “sorry but rip out and reframe.”?
Contractor has completed the exterior.

 

[jayrod12]

Can the two plates act like a wind beam?

 

[jerseyshore]

Easiest thing would probably be to just cut out the plate and add in new full height studs. Run some numbers and see what you would need for that height and add new ones accordingly. May need LSL studs.

 

[SWComposites]

Could you sheath the inside with 3/4 plywood?
Could you cut out the bottoms of the upper wall studs and insert a 4xX beam to span across?

 

[phamENG]

With the seam in the exterior plywood only a foot below the hinge, I'd doubt the ability of it to participate in forming a 'moment couple' and locking the hinge. Worth exploring, though.

You're in Louisiana, correct? So there's a potential for high wind loads. You may be able to do as jerseyshore said (welcome back, by the way). That will be the most robust method if it works. Of course, that's still a long way to go for a 2x4. LSLs will almost certainly be required for a) straightness and b) strength. It also has the advantage of not having to mess with the building paper and/or siding that is undoubtedly already in place.

I wouldn't be surprised if you had to cut out the floor band across the stair wall and put in a double LVL resisting the wind above and below in its weak axis. That's how I usually deal with these when detailing up front.

 

[kipfoot]

I second what phamENG suggested:

 

[HouseBoy]

I "third" what pham and kf wrote.

With the width = 8 ft and the height = 20 ft... I'd expect a wind girt at the location of the floor joists is likely to work better.
In fact, I have done this many many times HOWEVER... 3 1/2" is relatively small for a beam depth. I tend to use LVL material there too to limit shrinkage.
When I lay in something that matches the depth of the floor joists, I want to extend the pieces a few feet to each side of the opening. I also spec added fastening of the pieces together to promote composite behavior of the section (when they are oriented vertically).

I actually have "trained" my architect client (who does this type design fairly often) that we need 2x8 walls in this location.

 

[Brad805]

I have seen some use straps on both sides of the wall, but that ship has sailed since you have cladding on. I have never been a fan of that. The beam ideas seems to be a reasonably easy fix since this is not bearing much.

 

[Eng16080]

A few thoughts:
[ol 1]
[li]Cut-off the bottom of the upper studs and add a steel plate plus another 2x4 on top to make a flitch plate wind girt. Not sure what your wind loads are here but a 1/4" thick plate may well work.[/li]
[li]To gain a little extra capacity, you could brace the lower studs against the stairs and possibly use that to support the wind girt.[/li]
[li]Again, I don't know your loads, but I'd be surprised if a 3.5" LSL can really span 20 ft with an out of plane wind load on it. Like HouseBoy mentioned above, I've often ended up with 2x8 studs to span 20 ft. (BTW, where do you find architects that can be trained?)[/li]
[li]Unrelated to your question, but are the stairs really as steep as they appear in the picture?[/li]
[/ol]

 

[ChorasDen]

If the wall is 20ft, no 2x4 will work, doesn't matter how stiff or strong it is, it fails slenderness checks per NDS 3.7.1.

For a 20ft 2x4 minus plates, I'm getting a slenderness of 67.3 > 50.

You'll have to reframe the wall with 2x6 or 2x8 and move the stairs, or brace the wall somehow to eliminate compression slenderness checks.

 

[jayrod12]

I get that you could use a 5 ply 2x4 wind beam, essentially add 3-2x4 plies to the existing wall plates (assuming there are no splices in the current ones) and it may not work perfectly for deflection, but it gets it damn close, I'm getting L/220 for a 8'-4" span supporting 12 feet of wall wind load at a 20 PSF pressure. Strength works no problem.

 

[DoubleStud]

is there a lower roof outside by any chance? That may be able to help brace the wall. 2x4 stud is already pretty flimsy for a tall wall like this even if it was framed continuously. Not even sure you can get 2x4 that tall.

 

[jerseyshore]

You may be able to do as jerseyshore said (welcome back, by the way). That will be the most robust method if it works. Of course, that's still a long way to go for a 2x4. LSLs will almost certainly be required for a) straightness and b) strength. It also has the advantage of not having to mess with the building paper and/or siding that is undoubtedly already in place.

I wouldn't be surprised if you had to cut out the floor band across the stair wall and put in a double LVL resisting the wind above and below in its weak axis. That's how I usually deal with these when detailing up front.

Thanks pham, been crazy busy the last few months. Need to spend less time playing fantasy football and see what's going on around here.

I feel like in residential construction 90% of it is brainless, any moron can build a house and it could last 100 years. But it's these types of elements or semi-unique conditions that have a much higher probability of failure/ issues. Easily overlooked and simple to diagnose why after the fact. Just the lack of redundancy here always makes me overdesign this. No one likes to see a crack everytime they walk up and down their stairs. Add some new LSL studs or a wind girt, but beef it the hell up.

 

[BridgeSmith]

I like Eng16080's flitch beam idea. If it works, it's an elegant solution. A 4" angle or 3 1/2" channel section are other options, just not as easy to install and finish around.

...and jerseyshore, fantasy football is important, too. Gotta keep up with your team!

 

[wrantler]

Residential construction... Where we pick the lowest bid and then wonder why it is behind schedule and there's all these issues during construction .