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What do you think about this girder installation?

  • The hanger is inadequate support for the ceiling joists

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  • The beam is insufficient for the span and supported ceiling joists

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  • Your design seems sound

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Discussion Starter #1
I'm removing a section of an interior bearing wall, and I intend to install a blind header type girder to replace this wall, which supports nothing but the ceiling joists and attic storage.

I intend to use a 5 ply 2x12 #2 Douglas Fir built-up header to span 14'.

The ceiling joists supported by the beam will be 2"x6"x10'.

I will be using double 2x16 joist hangers (http://www.amazon.com/Simpson-Strong-Tie-HU216-2/dp/B004283G0M) to suspend these joists from the beam (one hanger on each side, supporting both joists where they overlap). The joist hangers will extend 8-3/8" above the top of the joist to attach to the beam, and they appear to give me 6-8 nails per hanger on the face of the beam and 4 nails per hanger in the joists.

Has anyone done this sort of work?
 

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I've done it a few times----I don't have a span chart so I'll leave that for someone else.--

How are you going to get a 14 foot beam up into your attic?
 

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Discussion Starter #3
I was thinking the gable vent might be a good way to go. I'm residing the house at some point, so I can always cut a hole in the old clapboard if necessary. To save myself a little trouble, I may do the assembly in the attic.
 

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The process is fairly simple---Let's see if someone with a spam and load chart can check the saddle beam size for you.
 

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I am guessing that you are doing this on the fly. Not too many times have I seen a 5 ply beam using dimensional lumber. I think engineers refer to this type of install as a sky hook.
 

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Discussion Starter #6
The process is fairly simple---Let's see if someone with a spam and load chart can check the saddle beam size for you.
I am guessing that you are doing this on the fly. Not too many times have I seen a 5 ply beam using dimensional lumber. I think engineers refer to this type of install as a sky hook.

I found some Canadian charts that make reference to 5-2x12 built-up headers. Here's a calculator:

http://www.hsh.k12.nf.ca/technology/cmhc/english/features/tables/table_11/index.htm

By "on the fly" do you mean "under the radar?" Well, I have a buddy at work with a brand new PE seal, but he hasn't done much structural engineering and he's not really familiar with framing best practices. He'll be stamping my sketches if I can't find prescriptive guidance to show the building inspector.
 

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I think you may have this over built----you are only holding up ceiling joists and drywall,right?

That span chart was for a girder holding up one floor of a house.
 

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Framing Contractor
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I agree that it is overbuilt. The hangers are probably overkill as well. I would imagine that some strapping would carry a 2x6x10 ceiling joist just fine.
 

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Civil Engineer
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Your buddy should rethink his willingness to stamp drawings. It is considered unprofessional (this means you can lose your license) in all states to stamp work which you did not have substantial control over, and for which you are not competent to perform. By your own statement, your buddy has a brand new PE stamp, and certainly should be aware of regulations regarding use of his stamp in an unprofessional manner, i.e. allowing you to pull a permit when he did not supervise the design. Unless he did supervise the design, but you did not state that.

In Massachusetts, you can perform your own design work without a PE stamp, and the building inspector MAY accept your work for purposes of giving you a permit, or he may reject it. Submitting paper with a bogus stamp is totally bad news, and you should not put your buddy in such a difficult position.

As to the design, well there are standard span tables that may cover your work. The trick will be proper installation.
 

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Discussion Starter #10
I think you may have this over built----you are only holding up ceiling joists and drywall,right?

That span chart was for a girder holding up one floor of a house.
Just the ceiling joists, drywall, and potentially storage. I think I at least a 4 ply header would make sense, just to leave options open.

I agree that it is overbuilt. The hangers are probably overkill as well. I would imagine that some strapping would carry a 2x6x10 ceiling joist just fine.
What sort of strapping do mean? Are you talking a 90 degree hurricane tie sort of thing, or do you mean strapping like I would use to suspend DWV or ductwork?

Your buddy should rethink his willingness to stamp drawings. It is considered unprofessional (this means you can lose your license) in all states to stamp work which you did not have substantial control over, and for which you are not competent to perform. By your own statement, your buddy has a brand new PE stamp, and certainly should be aware of regulations regarding use of his stamp in an unprofessional manner, i.e. allowing you to pull a permit when he did not supervise the design. Unless he did supervise the design, but you did not state that.

In Massachusetts, you can perform your own design work without a PE stamp, and the building inspector MAY accept your work for purposes of giving you a permit, or he may reject it. Submitting paper with a bogus stamp is totally bad news, and you should not put your buddy in such a difficult position.

As to the design, well there are standard span tables that may cover your work. The trick will be proper installation.
If I can deal directly with the building department, all the better, but, so far, I haven't found anything in the IRC (or any other domestic publication) that prescribes a built-up beam for the span I need.

As far as the installation is concerned, the ability to install the beam on top of the joists with the existing bearing wall in place will greatly facilitate precision work.

I'm not sure I would call my buddy incompetent to assist me. He's just going to be pretty slow with this sort of work. He has extensive experience as a mechanical engineer, but he takes the long route to some of the solutions he provides when I've asked him questions related to structural engineering. He definitely has a degree of control over the work I'm performing, but I'd like to facilitate his work by proposing a solution.
 

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It took me a while but I think I understand what your trying to do. (pictures and drawings make my poor little brain function better)

That is a pretty wild scenario, way over-sized-laminated lumber beam in the attic above the ceiling joists it is to carry, then to top it off the hangers will each carry two over-lapping C.J.s from opposite directions.

Mighty odd, I must say. I think you will save yourself money by getting an engineer to design something better for you, really.

I am not being an ass either, just good sense on this one I think.

Would it look something like this?

Andy.
 

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sounds pretty hefty (not to mention freaking heavy) for the load, however if you are following the span charts and/or overbuilt no worries.

Only thing to keep in mind is your point loads, at each end of the beam.
 

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Discussion Starter #13
It took me a while but I think I understand what your trying to do. (pictures and drawings make my poor little brain function better)

That is a pretty wild scenario, way over-sized-laminated lumber beam in the attic above the ceiling joists it is to carry, then to top it off the hangers will each carry two over-lapping C.J.s from opposite directions.

Mighty odd, I must say. I think you will save yourself money by getting an engineer to design something better for you, really.

I am not being an ass either, just good sense on this one I think.

Would it look something like this?

Andy.
That's exactly what I'm talking about. I was under the impression this type of installation was not that unusual. An engineer would have to come up with something pretty extraordinary to make up for the $200 fee.

sounds pretty hefty (not to mention freaking heavy) for the load, however if you are following the span charts and/or overbuilt no worries.

Only thing to keep in mind is your point loads, at each end of the beam.
I'll be sure to place blocking under the supporting studs to transfer the load to the block wall.
 
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