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StructuralEng
StructuralEng, Consultant
Category: Structural Engineering
Satisfied Customers: 7319
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: 1 year ago.
Category: Structural Engineering
Expert:  StructuralEng replied 1 year ago.

Hello

Expert:  StructuralEng replied 1 year ago.

I can help.

Customer: replied 1 year ago.
I'm not sure, can you?
Expert:  StructuralEng replied 1 year ago.

You're not sure if I can help?

Expert:  StructuralEng replied 1 year ago.

What future load on the roof?

Customer: replied 1 year ago.
Not sure at this time, it a flat roof and I could potentially build a deck on it.
Customer: replied 1 year ago.
it's a flat roof
Customer: replied 1 year ago.
Would a picture of the building help?
Expert:  StructuralEng replied 1 year 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 1 year ago.
16' span . I would like to work with wood but the load might be too much.
Expert:  StructuralEng replied 1 year ago.

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

Customer: replied 1 year ago.
oh sorry, the joists are 16" oc 2x6.
Expert:  StructuralEng replied 1 year ago.

What length are the joists?

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

Customer: replied 1 year ago.
Sorry for the delay I spilled a cup of coffee.
Customer: replied 1 year 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 1 year ago.

16' x 12'?

Expert:  StructuralEng replied 1 year ago.

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

Customer: replied 1 year ago.
Ok, forget the part about the deck and just advise on the replacement beam.
Expert:  StructuralEng replied 1 year ago.

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

Customer: replied 1 year ago.
Debuque, IA
Expert:  StructuralEng replied 1 year ago.

three 2x12 doug-fir no. 2.

Customer: replied 1 year ago.
12" is too much. how about a paralam?
Expert:  StructuralEng replied 1 year 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 1 year ago.
That is ok it is an interior support.
Expert:  StructuralEng replied 1 year ago.

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

Customer: replied 1 year 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 1 year ago.
the 2x6 span 12"
Expert:  StructuralEng replied 1 year ago.

12', not 12", correct?

Expert:  StructuralEng replied 1 year ago.

12 feet, not 12 inches, correct?

Expert:  StructuralEng replied 1 year ago.

Do you still need help with this?