How far can we span with an I-beam when removing a supporting wall?

The answer is that you will have to get a professional opinion based on the local codes. You will also need a permit to perform structural changes. I would contact your local building department. They will be able to answer your question and recommend a structural engineer who can properly specify the beam column and footing configuration you require.

Once you know the load, look at the available engineered wood I beams. They are stiffer than steel. There would be less vibration under dynamic load ( like people walking around causing long term stress on plastered joints upstairs. I can think of one brand called Silent Floor that is regularly used in new home construction to span up to 24 feet. Space might be an issue because they are taller than steel for a given span. But you can easily drill through the web to pass cables and pipes, and it is as easy to attach dividing wall studs and headers using traditional woodworking technology. They are much easier to handle, being significantly lighter than steel.

Six inch sounds okay, the web thickness is very close to 1/2 inch, that is quite thick for only a 14 foot span. If you feel safer with 8" go for it. I am running 22 foot spans in my shop with only 1/8 inch web thickness. I pull engines in the center of it. What ever you feel safest with is what you want.

Frozen's answer sounds correct. I know my daughter's house used the new engineered I-beams. You may want to look into those. They are totally straight, and support quite a bit of load. Ask your structural engineer about them.

Im not a framer but i have been in alot of basments doing new floors and 6" for a 14' span seems way too small to me. try this site.

http://www.martindalecenter.com/Calculators4_6_Civ...