I am building a new wall that will tie into an existing popcorn ceiling with a 2x4 top plate and sheetrock. The ceiling is popcorn and the wall will be painted, no texture. I don't want to install crown molding and I absolutely do not want to mess with the ceiling. I can accept a little bit of smudge factor because the wall is between 8' and 12' in the air (vaulted ceiling).
My question is how to mud the top of the wall tight to the ceiling? Just jab the knife into the ceiling with every downstroke? Is this scenario feasible?
Well there's the proper way and there's another way. If your walls are built and the wall rock is not up yet. You could remove an 1/2 of popcorn along the ceiling (1/2" chisel works great), and then slide the drywall between the top plate and the popcorn. This will require a clean cut that butts up to the ceiling the entire distance. This can be done. Nail or screw down a little further than normal into the studs so you will not have to finish directly against the ceiling.
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I think you're going to find it awfully difficult to cut your drywall tight enough to get away with just butting to the ceiling and caulking. You will likely have to carefully flat tape and mud at least parts of the joint. It will not be easy to keep excess mud off of the ceiling, but it can be done.
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