Yes you can typically cut through joists but you must make some additions known as trimmers and headers to the framing as well.
Cutting joists in attic without damaging drywall.
Jacking them up too fast may cause cracks in the walls and floors overhead.
These problems must be addressed firsthand prior to implementing any restoration steps.
The answer is maybe.
If you are removing only one joist make a mark on each end 1 1 2 inches wider than the rough opening.
Most often floor joists need to be sistered because of two problems either water damage which leads to rot or termite damage that crumbled the joist.
In order to maintain the support integrity of the ceiling or floor joist or rafter system it is important that if joists are cut that the load that was bearing on those joists be transferred to a modified support system.
Measure the old joists.
If you were to remove all the insulation you would see the drywall or plaster of the ceiling below nothing more.
A day until they re level.
If there was water damage make sure that whatever leaky pipe or condensation issue caused the rot is fixed.
Ceiling joists are typically 2 8 lumber floor joists are usually 2 10 or 2x 12 lumber.
Note that the trimmers run the whole length of the joists in place.
Cutting and or removing joists to provide an entry or access can be the most difficult part of the overall project.
This is best done from the attic.
Measure the length of the old joists and note how much they overhang any supporting walls or beams and the exterior walls.
Tack a beam under the sagging joists.
It is held in place by the ceiling joists which inside the attic become the floor joists.
If the attic were designed as living space those ceiling joists would become floor joists and be much bigger.
Without knowing anything about the readers house framing it s hard to say.
Both pieces should come out without damaging the painted surface.
That s a big size and strength difference between the two types of attic joists even if the joist spacing is the same.
Make pencil marks on the joists you will be removing.
The easiest way to do this is by building a rafter system from inside the attic in the area to be modified.
Score an entire box the shape you want keeping it inside the edge of the joist.
Set a hydraulic jack and post under the beam and jack up the joists about 1 8 in.
If you are not going to remove the insulation you.
The ceiling joists will not hold much weight being only 2x4 s.
Cut both ends perpendicular to the joists and then down the middle.
Nailing two 2x4s together will work to span about three joists unless the sag is under a weight bearing wall.
Robert from winnipeg manitoba asks about the safety of walking around in his attic first let s be sure not to fall into the room below.
Can truss members be cut.