Opening a Kitchen and Living room wall

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Duane

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I am starting to open the wall between my kitchen and my living room. This is a top floor with nothing above the wall in the attic except for 2x6 ceiling rafters running the 25' wide of the two rooms (two lengths of rafters that are nailed together directly above the wall I want to remove). The wall I want to open will be 22' in length between the two rooms.
I can either put a beam up in the attic and attach the rafters to that beam or I can have a beam below the ceiling but I would not want to go more than a 12'' below the ceiling.
Can someone tell me what size of beam I would need to use in this project? Thank you Duane
 

Jadnashua

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This may require some additonal considerations...essentially, instead of spreading the load over all of your floor joists, with a beam, it will be along the outer wall, maybe only one stud...not good. You may need to build up the wall structure at the ends down to the foundation to provide adequat support. To keep it shallow enough to meet your 12" requirement, you may need to go to steel...it WILL be heavy (as would any beam that length), and getting it in there may be one of the biggest problems you have. To keep the house from falling down, this must be engineered properly.
 

GabeS

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Seems like you're in over your head. Get somebody who's done it many times before to do it. As well as get an engineer to write the plans and have it inspected. This is not a project that you should do any guesses with.
 

SeattleSoxFan

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Though I agree with all the comments posted 'til now (especially jadnashua's who realizes you can't solve the problem by only looking "up" at the problem), I also think the answer may not be a beam...

You surely will want an engineer's input regardless, but it could be significantly easier... that is, if I understand the problem without pictures, or sketches.

My assumptions from what you have posted:

  1. The wall you are removing is parallel to the ridge
  2. The rooms have vaulted ceilings on both sides of the wall
  3. This wall's top plate is directly supporting the rafters
  4. The wall you want to remove does not go the entire length of the ridge

OK, so assuming those are all true...

You do not need to support the rafters at the ridge... as long as you have something keeping the rafters from spreading. Basically, the roof load will be balanced quite nicely with the rafters in opposition, but without something holding the walls together they will push the walls apart. A typical house has ceiling joists to hold the walls from spreading, but a vaulted ceiling has no ceiling joists. The wall you want to remove isn't really keeping the walls from spreading (presumably other parts of the house are doing that), but it is keeping the ridge from sagging (and then pushing the walls out).

An engineer is likely going only going to suggest one solution: add rafter ties (or ceiling joists). A beam also would work, but will mean more work unless adding extra posts, hardware, and footings to support the beams doesn't involve opening up several extra finished walls and floors. (Need to worry about everything from squash-blocks in the floor diaphragm(s) to the soil properties below the foundation)

You will have to tell him/her where you want them... You can find prescriptive codes for rafter ties at I believe either 1/3 or 2/3 the rafter span (your "rafter span" is 12' 6" BTW), but I would still have an engineer do it, stamp it, and give you a fastener spec too (i.e. not just a few nails wherever you can squeeze a nail gun in). The lower down the rafter tie, the lower the force required to hold it together. If you want it quite high (i.e. within 12" of the peak), you will end up needing to have metal plates fabricated to sister on the joists.

You can also choose to add them lower down and either drop the ceiling or have the ties exposed.

There's a fine homebuilding or JLC from ~2007 sometime that talked about moving/removing collar ties and the tremendous forces he ended up dealing with.

Anyway, talk to an engineer/architect and have them design the best solution for your desired result. DON'T rely on the lumberyard to spec it. They will get the "correct" beam, but they won't take the whole picture into account and, generally, won't worry about taking a distributed load and making it a point load and cracking your foundation or your gable end wall blowing out during a big snowstorm.

BTW, it's pretty easy to size that beam if you know the designed roof load and the span (22'). It's not a secret for engineer's only (though it's outside of prescriptive codes, so in most parts of the country an engineer would have to spec it). For the reasons others have mentioned the answer to the specific question of what size beam is ignoring the rest of the problem. Specifically, ~14,000 lbs of a problem! (with a 40/10 roof load)

As a contractor (carpenter), I talk with clients about this kind of thing a lot. They usually are interested in getting their envisioned result only until the actual costs start adding up, then we work together to get a good result at a reasonable cost. If everything is torn up, then the beam is simplest, if they just want to play with cabinets and flooring and "open up that wall while you're at it" I'd probably float the idea of putting a flat top on the vaulted ceiling unless cost is not a priority (haven't seen too many of those jobs lately). Of course they usually ask me to price out their original option, which I'm happy to do after they pay for the engineering to tell me what they're asking me to build! :)
 

SeattleSoxFan

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Some good reading on the subject...

These are both articles from JLC, 2007 and hopefully shows how competent pros approach this kind of problem.

This is not quite the same roofing problem, but it is the article I was remembering. The main point is a creative solution to removing collar ties with steel:
http://www.jlconline.com/cgi-local/...e.storefront/49c744a911b9889527170a32100a06b8

I think in that same issue there was a little engineering blurb about loads increasing as collar tie height rises, but that's a bit beyond my memory and my "library" of old issues is not particularly organized or complete. :)

This one talks about using a low-profile beam, but mentions very little of the support lower down. Still might be interesting if you do hope for a "slim" beam:
http://www.jlconline.com/cgi-local/...e.storefront/49c744a911b9889527170a32100a06b8

No charge for the research... this time. ;)
 

Jimbo

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If I read his post correctly, the wall in question is a load bearing wall. He describes ceiling joists crossing the wall. Instead of one long joists, two shorter joists each land on the wall in question and are supported by it. If I am reading this correctly, a serious beam will be in order.

I did not understand his comment about putting the beam in the attic. How do you "hang" the joists from that?

You could using proper temporary supports each side, cut the joists so the beam will slide up into the ceiling, and then use joist hangars on each side.

No matter what, this job requires serious building skills, and engineered beam, and likely will result in some cracked ceiling plaster!
 

hj

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how do you know?

SoxFan, how do you know that the ceiling joists are not lapped at that wall, thus requiring that they BE supported? How would the 25' beam be inserted into the attic above the joists? The weight of the roof will no longer be supported by the bearing wall, but it plus the weight of the beam will shifted to whatever is supporting the ends of the beam, and those points were never designed to hold that load. EVERYTHING about this revision screams, "Call a mechanical engineer or professional contractor who knows how to do this job."
 

SeattleSoxFan

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I assumed he knew the difference between joists and rafters... I guess that that was my mistake -- somehow I missed the "attic" comment.

If it's a standard-framed ceiling, it's a much easier problem... :) But, Duane, if you are having troubles with the basics then you should put down your hammer immediately! ;)
 

Duane

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I assumed he knew the difference between joists and rafters... I guess that that was my mistake -- somehow I missed the "attic" comment.

If it's a standard-framed ceiling, it's a much easier problem... :) But, Duane, if you are having troubles with the basics then you should put down your hammer immediately! ;)


Hi Seattle,
Thanks for you help. Maybe I better clarify. What I am looking to support is a ceiling joist. These are joists 16'' on center that go from outside wall to outside wall and the ceiling sheet rock is hung from this. This is also a flat ceiling. One room width is 13' and the other room is 12' and the joists overlap and are nailed together above the wall I would like to take out. I want to take out a 22' section of wall between the two rooms. There is no other load on top of the wall that I want to remove except the ceiling joists.

The roof rafters sit on the outside wall and angle up to the peak with no other support. I am trying to find out what size of beam I would need to use to support the joists. I went to my ******* and they told me that two 8" LVL would do the trick but I am a little leery. Hope this might explain more of what I would like to do. Duane
 

Scuba_Dave

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I went to my ******* and they told me that two 8" LVL would do the trick but I am a little leery

Who ? :confused:

You need to span 22' 6"
You generally need triple 2x at either end to support the beam
But that is what an engineer will be able to specify
You also need to make sure that the support at each end of the beam will go all the way down to a foundation/support structure
Will either end be supported by the outside wall/foundation of the house?

One reason you will not receive much input as to the exact beam size is that every load is different & most people do not have access to the software that will size a beam this long

I had to go to 2x 12" LVLs' to support a 18x24 floor
That's more then just sheetrock - floor load
But gives an example
 

Duane

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Hey Scuba Dave,
Thanks for your help. I do have solid support under the the supporting studs. I had only planned on going with two 2x4 to mount the beam on but adding a third shouldn't be a problem. I would think two 8" lvl would be enough support but I may try talking with some other lumber yards to see if they can help me out. Duane
 

Jadnashua

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Often, the building inspector is going to want to see an engineer's stamp of approval on the plans, so you'll need to address that issue anyways...might as well do it now and ensure what you have will work. My earlier point is that now, that beam will be supporting the entire roof load along the studs on the outside wall. One stud, and maybe even three may not be enough. And, that support must be mirrored on the lower floor, if the floor of that room doesn't sit directly on the foundation. The ceiling joists are likely also acting like a collar tie holding the opposite walls from bowing out from the roof loads. This could cause both lift or weight on that joint in the middle...somebody that knows must 'run the numbers' for the entire system or you are at risk.
 

SeattleSoxFan

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2x8 LVL's do sound a bit undersized, but the beam is actually not under all that much stress. It's supporting the ends of the beam that will get the brunt of the load.

Any inspector is going to want a stamp unless it is clearly in the code already. LVL's are quite standard in construction, but their loads are not in the codes. You can get that stamp from the LVL manufacturer, but as was pointed out earlier, they're not going to stamp the support system or verify existing conditions. If the support is accessible to the inspector, the mftr's stamp could be enough.

I'm still not an engineer (happily), but I both like numbers and usually have to do some simple-span calcs on projects (though from 99% of the decks I see, that's apparently unusual). But since you've only got simple spans, let's take a stab...

If it is an uninhabitable attic area the load is only figured at 10lbs/sf (the joists themselves, drywall, lights, fans, etc.) In your case the ceiling load is: 550sf * 10lbs/sf = 5500lbs. 1/2 of that is carried on the two side walls, and the wall has the other half (2750lbs). The new beam is getting that load distributed over its length at about 125 lbs/lf. That's not a terribly sizable load, but you have a decent span at 22'.

Just for fun I looked it up at a manufacturer's site: http://www.ilevel.com/literature/TJ-9000.pdf. They don't list things like sistered beams in the documentation, but we'll assume it just doubles it as long as you follow their fastener spec. They don't even give a rating on 2x8 (1-3/4"x7-1/4") LVL's spanning 22' but looking at the charts it looks way undersized as it's only rated for 64plf @ 12' (we're looking for 1/2 of 125plf @ 22'). From what I can tell with that chart (p18 is what I'm looking at), 11-1/4 is what you're looking at (sistered or just 3-1/2") with its 148plf rating.

I'm sure the manufacturer has more details behind their charts and can specify and stamp. For instance, that chart assumes a floor load configuration with live loads that you don't have.

The walls that will support the beam are going to take the load at a point, so they get the new 1375lbs to deal with. That's not astronomical, but it needs to be figured with a continuous load path through the floor system down to the soil. A 4x4 can easily support that load (actually so can a 2x4) and 1sf of soil bearing is all that's required (assuming that's its only load), though I would probably make it 2'x2' if I'm cutting a slab for it.

One last comment... If you do end up with something like a 4x12, you can hang the joists from it, or leave them as is and put the new beam below. You have to support them temporarily in both cases, but you can create a flush beam if you have the attic space to "poke" the beam up into and hang the joists even with the bottom. You also can just leave a column or two (that you pretty up or hide as you wish) which will cut down the span and size requirements significantly... i.e. one center post would only require a single 1-3/4"x9-1/4" LVL! Ironically, the chart suggets sistered 2x8's are still insufficient in that case. :)
 
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