What size are the joists in my 1st and 2nd floor flooring system (8″, 10″, 12″)?
On typical first floor systems the joists are usually 8″ or 10″ but they can be 12″ or 14″ if required.On typical 2nd floor systems they are 8″. The gage of floor joists are to be determined during design based on spans and loads. Remember, the structural frames handle the load transfer so the structure is quite different than a stick built house.
