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engineered beam to replace load bearing wall


dmrlook's Avatar
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Join Date: Sep 2006
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MN

05-17-08, 02:38 PM   #1  
engineered beam to replace load bearing wall

Hello all. I am preparing to move a load bearing wall about 2 foot into my garage (garage gets smaller, interior room gets larger) to expand my laundry room/mud room. Above the garage/laundry rooms is the attic with trusses 24" OC. The trusses were built assuming this wall would remain where it is (I have confirmed this with the company that made the trusses) and so if I want to move the wall, I need a header to carry the load of the trusses/roof above. The wall that I want to move is just under 14 foot and is 2x6 construction. You would be surprised how many lumber yards I had to call before one finally ran the numbers for me on what size engineered beam I would need to span this distance. They came up with 3 ply 2x18" by 14 foot long. I am surprised to see that the header needs to be 18 inches in depth. That would make my finished ceiling just under 6.5' in height, which is obviously not acceptable. Especially for those of you who are tall.

My question is, does the height of this beam make sense to you all. If I wanted to minimize the height of the beam, could I go 4 or 5 ply?

What about going with steel? I don't want to pay a structural engineer all the money to do the analysis which is why I went with a microlam beam (lumber yards don't charge to have their engineers do the work) but maybe I have no choice.

Your thoughts?
Thanks,
Rob

 
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leejosepho's Avatar
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05-17-08, 03:17 PM   #2  
Posted By: dmrlook Hello all. I am preparing to move a load bearing wall about 2 foot into my garage ...
The first problem there is that the new wall will need a foundation stronger than the garage floor.

Posted By: dmrlook ... if I want to move the wall, I need a header to carry the load of the trusses/roof above.
Not necessarily. Blocks and/or plates could possibly be added at the new load point.

Posted By: dmrlook What about going with steel? I don't want to pay a structural engineer all the money ... but maybe I have no choice.
You need someone who understands loads and framing to detail your options, and the expense of that would ultimately be far less than repairing an insufficient modification.

 
dmrlook's Avatar
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05-17-08, 03:51 PM   #3  
Thanks - I know about the foundation. I will be dropping 42 inch footings under the garage slab to support the new wall. Got that once covered and am doing per local codes.

I looked into plates at the new load points, but the truss company was not interested in helping me define what these should be, and I don't want to pay the 2-3 thousand in engineering costs that was quoted to me to do the analysis.

 
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05-17-08, 04:27 PM   #4  
Posted By: dmrlook I looked into plates at the new load points, but the truss company was not interested in helping me define what these should be ...
Try sketching a 14' truss with your roof pitch and a 2' cantilever on one end, then get a quote and hopefully a picture from a lumber yard somewhere. As long as you have the foundation figured out, and if that job was mine, I would simply add some cut-to-fit 2x6 blocks (the width of the new wall, I am guessing) and plate them with 6" strips of 1/2" plywood. The only additional factors might be the matters of any specific load (such as rafter tails or whatever) over the cantilever, or the load of anything else sitting above the existing wall. I have yet to actually visualize your framing, so I do not know everything that wall is presently doing.

 
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