I have an old barn with a up stairs and down stairs. Im looking to replace the floor joists that are broke. The joists are actual trees that are trimed to fit. They are probably 10" diameter with no post support between the span. The span is 25 feet.. The joist between eachother is about 3 feet. What would be the best replacement and what would carry 1 to 2 ton. Thanks.
While you do not have enough loading information to give a more exact answer, you could typically use taller and/or larger flange I-joist or 4x2 floor trusses. The key is height to whatever you put in.
I-joist can easily give you the span you need, its just a matter of loading.
For comparable cost at longer spans and higher loadings, floor trusses can pretty much do what ever you want if you give them enough height. Just locate a truss company and meet with them and they should be able to guide you on a proper truss design and get you a quote.
For a barn, I would probably go with I-joist but if you need to run any mechanical or plumbing, I would recommend floor trusses.