Originally Posted by blucher
Then once all joists were beams of wood but commonly replaced by synthetic beams called joists?
Since a great many houses were blown off their foundations in the recent tornadoes would this joist install time also be used to further anchor frame & foundation?
The definition of "joist" doesn't depend on its composition, but its purpose. Whether the subfloor sits on 2x10 wooden boards, or one of these engineered structural members, the thing the subfloor sits on is called a joist.
Got a full basement? In most basements, there are posts, vertical members that support a big chunk of wood. That big chunk of wood can be a 10x10 tree trunk, several 2x12 boards, a solid steel I-beam, etc. That big chunk of wood typically runs the full length of the basement, and it's usually the lowest horizontal, structural member in the ceiling of the basement. If you have to duck when you walk across your basement, the beam is the thing you're most likely to hit your head on. (If you have a crawlspace, the construction is similar.
The top of the basement walls is called the "sill". The top of the beam is the same height as the sill. The Joists sit on top of the beam and the sill. On top of the joists is the subfloor, usually a sturdy plywood.
I've never seen a renovation go so far as to replace more than one or two joists, and then only in extraordinary circumstances. Once they go into new construction, they typically stay put until demolition.