I am adding on a second story addition on existing one story house. The floor sits on centrally located I-beam and supported by 4 inch diameter steel posts. The beam is 4 inches wide and 6 inches high and quarter inch thick. The beam will carry 2 floors and a 4 and half by 12 pitch roof in northeast region of New Jersey. The house is 26 feet wide. The spans between supports are: 89 inches-86 inches-8’5″-49″-11′. 11 feet span goes over the garage. Is there a published span chart for such steel beams or should I consult an engineer? Thank you all for any suggestion.
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There's a lot more to worry about when adding a second floor than just the center beam. Headers in exterior walls, Foundation and footing design, and of course local codes. An engineer/architect familiar with your building codes would be a good idea.
One suggestion come to mind - If you use floor trusses and roof trusses, you could clear span the 26' and not add any additional load on the steel beam. But that would still put more weight on the exterior walls/foundation, so you should still probably consult an engineer.
Don't steal. The government hates competition
I agree with Boss Hog. There's much too much going on for a design-it-yourself project. Get an Architect (the State of New Jersey is particularly restrictive about Engineers' involvement in residential building design). Besides, you'll have to file plans and specs with the local building officials anyhow. Oh, by the way, the beam (W6x12 from your description, but don't quote me) sounds light for the application, FWIW.
> (W6x12 from your description, but don't quote me)
Steel beam nomenclature is kinda obscure. What that means is:
W: Shape designation, in this case, wide flange. Very widely used for beams.
6: Height in inches, as you measured. This is the only thing that's easily measurable
x: Just means "by"
12: Weight per foot in pounds.
If you want to dig further into this yourself, go to your library and check out "Simplified Engineering for Architects and Builders" by Parker & Ambrose. See chapter 9 for steel beams. Your building department probably won't let you do your own engineering, but this will make you a better informed customer when you do business with an engineer.
-- J.S.