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StructuralEng
StructuralEng, Consultant
Category: Structural Engineering
Satisfied Customers: 7077
Experience:  Structural Engineer
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I'm replacing a 16.5' span that held up a enclosed porch

Customer Question

I'm replacing a 16.5' span that held up a enclosed porch extension 4x6. it is currently braced at 8 feet with a 4x4 post. I want to eliminate the middle post and have an open span of 16'.
I need this over-engineered to handle future load on the roof.
Please provided your guidance and maybe a simple formula to calc stress load capabilities.
Submitted: 9 months ago.
Category: Structural Engineering
Expert:  StructuralEng replied 9 months ago.

Hello

Expert:  StructuralEng replied 9 months ago.

I can help.

Customer: replied 9 months ago.
I'm not sure, can you?
Expert:  StructuralEng replied 9 months ago.

You're not sure if I can help?

Expert:  StructuralEng replied 9 months ago.

What future load on the roof?

Customer: replied 9 months ago.
Not sure at this time, it a flat roof and I could potentially build a deck on it.
Customer: replied 9 months ago.
it's a flat roof
Customer: replied 9 months ago.
Would a picture of the building help?
Expert:  StructuralEng replied 9 months ago.

I will assume it's supporting a deck then. What is the joist length supported by the beam?

Do you want wood or steel?

I can provide the size as this question. If you need detailed calculations, I can provide that as a premium service.

Customer: replied 9 months ago.
16' span . I would like to work with wood but the load might be too much.
Expert:  StructuralEng replied 9 months ago.

The beam spans 16.5' and the joists span 16'?

Customer: replied 9 months ago.
oh sorry, the joists are 16" oc 2x6.
Expert:  StructuralEng replied 9 months ago.

What length are the joists?

They are on one side of the beam only, correct?

Customer: replied 9 months ago.
Sorry for the delay I spilled a cup of coffee.
Customer: replied 9 months ago.
All potental deck supports are centered on vertical walls on 3 sides except where this beam is. The entire deck will be no more than 16' X 12"
Expert:  StructuralEng replied 9 months ago.

16' x 12'?

Expert:  StructuralEng replied 9 months ago.

You will need four 2x12 doug-fir no. 1 or five 2x12 doug-fir no. 2.

Customer: replied 9 months ago.
Ok, forget the part about the deck and just advise on the replacement beam.
Expert:  StructuralEng replied 9 months ago.

What is the city and state so I can look at snow loading?

Customer: replied 9 months ago.
Debuque, IA
Expert:  StructuralEng replied 9 months ago.

three 2x12 doug-fir no. 2.

Customer: replied 9 months ago.
12" is too much. how about a paralam?
Expert:  StructuralEng replied 9 months ago.

7" x 9.5" 2.0E LVL, but you will need to be VERY careful to keep it protected. LVL are not for exterior use.

Customer: replied 9 months ago.
That is ok it is an interior support.
Expert:  StructuralEng replied 9 months ago.

Great. Just to be clear, this beam will support nothing more than the 12' joists, correct?

Customer: replied 9 months ago.
in this case, the roof is made up of 6" joists on 16" oc. perpendicular to the spanning beam. flat roof.I'm sorry if I'm not using the correct eng. terms, I'm not a engineer.
Customer: replied 9 months ago.
the 2x6 span 12"
Expert:  StructuralEng replied 9 months ago.

12', not 12", correct?

Expert:  StructuralEng replied 9 months ago.

12 feet, not 12 inches, correct?

Expert:  StructuralEng replied 9 months ago.

Do you still need help with this?

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