Non load bearing walls can run any direction in a house. The thing that makes a wall load bearing is that it supports the weight of the structure and is usually at the endpoint of an upper floor joist. Sometimes these walls will be built out of 2"x6" lumber instead of 2"x4" as in regular walls.
It depends what they are constructed of- if they're to be built of heavy material such as stone or brick, then yes they do. If they're just quite literally partitions made of plasterboard with an internal timber frame, then not necessarily. Although not required, it's good construction practice to stack studs over floor joist. This allows for heating,Plumbing and other trade an opportunity to use the cavities to run floor to floor.
Joist = one of the parallel pieces of timber to which the boards of a ceiling or floor are fastened
Floor joist or ceiling joist? Floor joist have a board on the end all the way along the side of the building called a rim joist. Like the cross bar on the top of a T. Ceiling joist are nailed down into the top plate of the wall and to the rafters where possible.
Joist possibly ? A joist is the boards under the floor and above the ceiling that span the room or building. What the floor or ceiling is attached to.
There are several ways, but probably the easiest way would be to temporarily buck under the afflicted ceiling joist with a 2x6 temporarily, until the joist is in line with the others. Then go into the attic and cut and attach a 2x6 to the joist and vertically to the roof ridge. Remove the buck. The joist should stay in place.
beam transfer loads from the joist to the wall or column where it supports..
Joist
A joist, either floor or ceiling are the boards that go across the building and tie the walls together. A timber joist would be a rough sawn beam. Basically a tree that has been squared up.
600
it depends what your fire codes read. check with your local bldg inspector or code enforcement office. some municipalities wont allow it if theres no fire barrier.if there are no code violations, as long as your top plate is secure, then there shouldn't be a problem.
Depends on what pitch the roof is. Measure the ceiling joist to a point or to center and then plumb to the rafter and do the math. 3, 4, 5, x 12 pitch rises that much per foot of distance on the ceiling joist. 3x12 pitch, 12 feet to center of joist, 3x12=36. 36 inch rise from the edge of the roof to the center.
These are used to secure the ends of ceiling joist etc. used to form hatches /stairwells.
The factors that are involved are the span you are covering, the type of roof and the pitch of it. How you are bracing the rafters. Wider the span, wider the joist. 2x6 is usually enough for most house construction.