When i draw plans i locate joists under bearing walls only for parallel walls off layout but i do it with two joists spaced apart the depth of wallplates above.
Floor framing support wall above parallel to joists.
Score 1 for being non load bearing.
Thus for a 2x4 bearing wall two joists are below spaced 3 1 2 apart directly under.
The blocking provides a nailing surface for walls that fall between joists and serves as an evenly spaced fastening surface for finish materials such as drywall.
Floor joists and ceiling joists serve similar purposes.
Score 1 for being load bearing.
Unless you have a finished attic the ceiling joists are typically exposed.
In some circumstances the wall s top plate aligns with a parallel joist which provides an anchorage surface but still requires blocking to accommodate ceiling drywall.
Nonetheless this does not ensure good floor performance.
If the joists are parallel to the new wall adjust the layout so that the wall is directly under a joist.
This wall is running parallel to the floor joists above see picture 4.
This verification can be achieved with our forte software.
If the joists run perpendicular to the wall an adjustment should not be necessary.
Makes the plumbers and electricians smile.
However the floor joists must also be adequate to support the additional load from the wall.
For better performance the designer may wish to add a joist or blocking panels below the non bearing wall.
However there is a large double 2x10 header above the entry way see picture 4 in this wall supported by a jack stud on either end see picture 5.
You may need to lift insulation or plywood to see the joists.
The recommended detail for.