Floor Joices

Standard is 16 inches from the center of one to the center of the next one. Certain building codes and load requirements can change that dimension.

Well, usually. It will end up being one of 12", 16", possibly 19.2", and rarely, 24". If you use either of the latter two, you end up having to be careful about what you use for a subfloor. Look up "span tables", online.

I submit that the way this question was asked implies that you're awfully far behind the curve for what you need to know before tackling a DIY building project of this magnitude.

I think you should spend a couple days with a book like "wood frame house construction" by L. O. Anderson, William Oberschulte

--Goedjn

Andy comments:

Good advice. Also, when you look up the subject, try using "floor joists", and you will get more hits.....

:>))) Andy

For a low attic, it probably is.

Mayhaps he thought this was a different kind of newsgroup entirely and he meant "Joyces."

-Frank

You mean JOISTS. Most are 16" centers (leaving about 14 1/2" between) but it is possible to do other methods in certain cases. The only time I've heard 12" OC is for a deck using the Trex or other hybrid materials.