steel post requirement for suspended porch

[spettler]

I am planning to build a porch on the rear of my house. The floor area will be 40 ft. X 10 ft. The 40 being the length of the house. The porch will be 20 ft. pff the ground. I plan to use 4 steel pipes to support the support beam which will support the floor joists @ 8 ft out. How do I determine the steel pipe requirements?

Thank you in advance,
Steven Pettler
spettler@earthlink.net

[bkrahmer]

Your best bet would be to consult a structural engineer. I assume you used one to size the steel beam. If so, he should have also told you what to use for supports. Or, looking at it another way, he should have needed to know the post details to spec the beam.

[spettler]

I have yet to consult an engineer for anything (the bean).

I was planning to use 2x12 for joists and 2x12 three wide for the beam. I made this decision form observing other like structures!!

Shouldn't there be a reference book that I can use to find requirements (like what the engineer will use!)

[bkrahmer]

I would normally give recommendations on something like this, but since it's 20' up, that scares me. I wouldn't feel right saying anything other than to consult an engineer.

[spettler]

thanks for reply.

Would you be familiar with a text I could research?

[bkrahmer]

2x8 at 16" oc will be fine for your floor joists, since your span is only 8' (2' cantilevered.) I would use the Parallam specifier guide to determine my beam based on the floor load and any possible roof loads, and the post spacing. http://www.trusjoist.com/PDFFiles/2060.pdf Doing some simple math will give you what your design load would be for each post. What I don't know is how much, if any, that you need to oversize it since it's pretty far off the ground; and I don't know anything about sizing steel anyway.