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I've opened up a lath and plaster of a non bearing wall in my home built in 1924 (had a structural engineer look at it to confirm) but only partially - 5" under the molding (10" height). This molding I would like to keep. Also, due to electrical wires/outlets that are still needed, I would like to keep the wall as a U shape opening with lateral widths of less than 12" (as slim as possible without becoming an eye sore). Studs are 2"x4" at 12" on center.

The structural engineer said that I don't need a header to support the teeth studs that will result from the opening. Is that true ? The opening is rather large, over 10'. To be safe, should I still put a header? If so, what would be the minimum height I would need.

Edit: I remembered I had a photo taken while taking the plaster and lath down.

Wall opened

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  • So you're turning a once solid wall into a 10' wide arch? I'm having a hard time understanding what's going on. What is Teeth Studs?
    – JPhi1618
    Nov 30, 2015 at 16:21
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    I think the reference to teeth studs are the look the cut studs take when they are cut out of the way to make the opening. In other words, cripple studs over the opening.
    – Jack
    Nov 30, 2015 at 16:26
  • Headers are for supporting loads above. If it's a non-load bearing wall, then there is no load above, so no need for a header.
    – DA01
    Nov 30, 2015 at 16:27
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    I agree, just a header as it still would be called, but only heavy enough to carry the dead load of the wall over the opening. I would use 2X6s at the least. The equivalent of the same in 1 3/4" LVLs would be ideal.
    – Jack
    Nov 30, 2015 at 16:32
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    I guess I still don't get it because you're talking about using a 6" LVL to support 5" of wall? I think you guys better be sure you're on the same page - seems like a lot of over engineering in my head.
    – JPhi1618
    Nov 30, 2015 at 16:57

2 Answers 2

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If it were me, I would use 2- 1 3/4'x5 1/2' LVLs. They shrink very little, hold up more than you will ever need for the dead load of the wall. The crown is attached to the wall, but it should be attached to the ceiling as well, at least a 5" crown should be.

Before setting the beam, cut the studs level, and if possible, preload the beam/header by shimming the cripple studs, to insure all are snug/tight to the header.

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  • Thanks @Jack. I did not know they make LVLs that small 51/2". So at each end I need a king stud and a jack stud underneath the header. What kind of bracing is required ?
    – Adrian S
    Nov 30, 2015 at 16:52
  • You can get a 11 1/4" and rip it if availability is an issue. Yes, always a king and jack stud at the ends. If it saves material you can take the header to the existing studs and add jack studs to get the opening you need, they can be spaced apart if needed. That will need only 8' studs instead of trying to cram a 10' stud in place. Make sure there are 2-2x at the opening to nail the trim to. No other bracing needed. I made the assumption the walls are taller than 8'.
    – Jack
    Nov 30, 2015 at 16:56
  • I have to agree with the comments above that this sounds like over-engineering. That said, if cost isn't a concern...sure, why not?
    – DA01
    Dec 1, 2015 at 4:25
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    I consider it a safe guard, an investment in crack proofing. I have seen 2X4s set flat sag under their own weight in a 10 ft run. Yes it is over engineering, but the wall will not divulge how it is constructed unless it is fully removed, something that was clearly stated, and understood since the crown is plaster. In houses built in the 1920s, I have seen top plates that are non existant, studs nailed only to the nailer that the plaster lath is nailed to that is part of the ceiling. That is not a lot of weight, but gravity has nothing better to do than press down on stuff.
    – Jack
    Dec 1, 2015 at 5:01
  • Yea, the shrink proofing is a nice benefit so can't argue against that. I also agree that I wouldn't use a 2x4 flat-side for the span. It could be fine assuming the 'teeth' studs are properly attached to the top plate, but there's no guarantee of that.
    – DA01
    Dec 1, 2015 at 5:13
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I'd suggest making a 'beam' out of the 2x4s you're taking out. This beam will only have to carry a tad more than its own weight. And those studs are likely old grown so pretty solid to begin with. Lay the 2x4s on their edge and glue and nail together (overlapping as needed to reach the 10').

Aesthetically, however, I'd strongly suggest leaving a few (4?) inches below the crown molding to give the impression that there's a structural beam there. Otherwise, the molding wouldn't seem to have a purpose just floating there off of the ceiling.

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  • Using the old material is a good idea to keep the strength up using 2X4s, the old material has already shrunk as much as it is going to. I typically use the cut out studs to use as the jack studs, something I forgot to mention in my post.
    – Jack
    Dec 1, 2015 at 5:08
  • I was definitely contemplating on using the existing studs - at least for the jack studs. You cannot see in the photo but there are 2 entrances on the right side where the header is at the top and covered with nice wood trim just at the molding level. I was thinking on replicating that if I could. So if I go your route - then I would be doing just that. There was another factor I was considering - the above plaster is held by lath which adds works like a header since is connected from end to end and does not allow for a lot of lateral movement.
    – Adrian S
    Dec 1, 2015 at 18:25

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