Size of header for opening a load bearing wall.

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  #1  
Old 04-04-05, 03:32 PM
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Size of header for opening a load bearing wall.

I have a wall with a walk through opening appoximately 50" wide. I would like to expand that opening to about 160" wide. The wall is a load bearing wall. I am unsure what size the header should be. Can someone please steer me in the right direction? I live in NH and I know that building codes differ from state to state but suggestions would be greatly appreciated.


thanks,

Dharma
 
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  #2  
Old 04-04-05, 06:42 PM
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Your talking about a 13'4" opening on a bearing wall. You need to get an Architect or Engineer for that.

Joe Carola
 
  #3  
Old 04-04-05, 06:50 PM
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Need more information

What is it supporting - Roof or Second Floor or both?

How much of the floor/roof above is being supported on this wall? IOW, how far to the next bearing wall ( on each side f it's a interior wall )?

If I know this I can give you a rough idea but it will still require a licensed Architect or Engineer in your state to provide engineering calcs for the building department.
 
  #4  
Old 04-04-05, 07:23 PM
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A stamp isn't required for a residence, is it? I was told that by a PE... At any rate, something like this definately exceeds standard dimensional lumber, and would require something more- LVL should easily handle it, and the engineering is done. Just grab a span table and drill down to the right column and you should be set Your local engineered lumber yard can help you out more; I know TrusJoist has span tables up on their website you can check out for reference; other brands of LVL will be similar: http://www.trusjoist.com/
 
  #5  
Old 04-05-05, 05:23 AM
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Big Opening

dharmilism:
One of the answers you received is bad advice. You most definetly need an engineer wheather it is private or with your building permit section to take a look at this. What appears to be easy, is going to require alot of work. Since this is a load bearing wall, special consideration must be given to several aspects of your project. Talk to your permit people first then go from there. Good Luck
 
  #6  
Old 04-05-05, 08:35 AM
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Jack, would the laws of what requires an engineer's stamp vary from state to state? I don't think my PE friend would have said 2-story residences don't neet a stamp if they didn't, and I asked him quite directly on this since my project includes several places where calculations are required. After all, that's what code and span tables are for- to allow for the construction of structures without having to redo the calculations every time you nail up a stud or chose a fastener. It seems absurd to expect a homeowner to hire an engineer just to use an I-joist or LVL beam in construction, especially when the manufacturer publishes tables expressly for that purpose.
 
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Old 04-05-05, 08:51 AM
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span tables

for I-joists and LVL's have already been designed by an engineer no need to redo the calculations. If your not sure of the load on the beam provide the supplier of the beam with a set of prints and they should be able to determine if the load can be carried by their product or not
 
  #8  
Old 04-05-05, 10:51 AM
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Span Tables

Span Tables are fine for joists with standard loading and for LVL's where the load per foot is known. For a Beam such as was requestewd here the load would first need to be determined and it would need to be established that the imposed loads are just "uniform". If there are any point loads they would need to be factored in. In addition, without knowing the tributary area (floor, roof, etc) there is no way to determine exactly what the uniform loads are.

Just because a project is residential doesn't mean that some calculations wouldn't need to be done - at least to the point of determining what loads to use in looking at the tables. In some cases the tables wouldn't apply and some additional calculations would need to be done.

That's why I asked for details........
However, if the configuration looks exactly like one of the examples given for the TJ LVL tables then you could use the tables as shown. But in any event, you will need to do some temporary wall supports in order to install whatever is needed.

BTW, even if a "stamp" isn't required, the building department will want to see calcs for such a long span "header".
 

Last edited by Joe.Carrick; 04-05-05 at 11:09 AM.
  #9  
Old 04-05-05, 12:42 PM
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Header:

Joe C:
You are absolutely correct. By cutting out that much wall, you will not only have live loads to deal with, but dead loads as well. The live loads will be transfered to the floor and adjoining walls. All the tables in the world will not tell you this. I have no doubt that a LTV will be needed, but how many, and what size. For instance on just a 16' garage door opening, the UBC calls for 2 LTV"S 17' long. 2x12's. This is not in any tables. As a civil engineer, I have all the tables of everything. Thanks for your input guys. We want to remember, that we are dealing with another mans house we have never seen. We must always work on the side of caution.
 
  #10  
Old 04-05-05, 06:48 PM
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Smile

Hi Jack,

Of course I'm right - I'm an Architect.
 
  #11  
Old 04-05-05, 07:30 PM
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Header

Joe:

I love it when a plan comes together.

Jack
 
  #12  
Old 04-05-05, 07:39 PM
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Joe,

Just to add my 2 cents worth.

I just installed a garage door header up north and there they would not allow me to use 2x12's as what was once allowed. Now you either use 2 - 1 3/4" x 11 7/8" LVL's or GluLams.

Now up North in Michigan just recently, I was not allowed to use LVL's but rather had to install a 2x6 wall for the garage door opening to support the header. The header had to be 5 1/2" x 14" GluLam. It was a surprise to me but there will be no sagging header.

Hope this helps!
 
  #13  
Old 04-06-05, 03:06 PM
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Talking

First I want to thank you all for the information! Here is some additional information. I figured the wall was load bearing when I noticed it was in line with the loli columns in the basement. The wall is in the center of the house so I figured it had to be. This wall does not span the length of the house though. It does not support any second floor walls directly. There is a wall running parrellel to it on the second floor about 5' away. The wall only spans about 19' in length which is not even half the length of my downstairs. The wall comes off the center of one of the exterior walls @ 90 degrees if that helps with anything. But I will get the blueprints from town hall and then cunsult a expert.

Thank you everyone!
I will still read any post you guys might still put up.

I live in NH if that helps too!

Dharma
 
  #14  
Old 04-06-05, 09:41 PM
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How to tell if it's load bearing

If you remove a section of drywall at the ceiling where the wall and the ceiling meet, You should be able to see if the joists above are actually sitting on the wall or if there's a space between the top of the wall plate(s) and the joists. If there is a space (about 1/2") then the wall is NOT loadbearing and you can take it out with impunity.

If there isn't a space then it might be load bearing. The fact that the wall isn't continuous for the whole length of the house doesn't really tell you because there may be a beam concealed in the ceiling. The fact that there are lally columns below this wall is a possible indicator but nothing is for sure.

How thick is the second floor? What's the distance from the outside wall to this wall? That information will give us a chance to make a better guess.
 
  #15  
Old 04-07-05, 06:33 PM
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The 2 exterior walls running pararell to this wall are approximately 12'3" from the wall (both are the same distance from the wall). The second foor is approximately 12" thick. I hope that helps a little. I will take a look by removing some of the dry walll in the ceiling to have a look to see if there is a gap or not soon.

Thanks,
Dharma
 
  #16  
Old 04-07-05, 07:33 PM
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24' would be too long a span for 2x12's even at 12" o.c. so it's very likely that this is a bearing wall. 2x10's at 16" o.c. would easily span 12' so I am pretty sure that it is a bearing wall.

Most likely there is a beam that runs from the end of this wall to the other end of the house and is concealed in the ceiling.
 
  #17  
Old 04-17-05, 12:36 AM
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Hey everyone thanks for all the imput. My wife just pointed out that half the opening we wanted in the wall was for a breakfast counter top (half wall) where people could sit at. So in the middle of the opening we would have a place for a column to seperate the walk through and counter which could be used to carry some of the load. I think that might help. Would that make enough of a difference? i will hire a carpenter for this but I would still like everyone's imput please.

Thanks everyone,

Dharma
 
  #18  
Old 04-18-05, 02:38 AM
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Oh, it makes a HUGE difference! Length/deflection is an cubic relationship- a small amount of difference in length makes an extremely large change in deflection. Halving the length of your beam decreases the deflection on it by about 8x. Or, you can now use a smaller beam. The other considerations still apply (namely, I don't think you'll find anyone here willing to tell you precisely what beam to use without knowing what else it's supporting) but it's a whole lot easier with the smaller span
 
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