drywall
Just got my drywall up in a room that I will be installing crown moulding in.
Is taping the joints where the ceiling meets the wall necessary if its just going to be covered up? I've heard mixed answers, some including just using a single layer of firetape.
Personally I would not lose a lot of sleep over this. The molding will probably cover it up. If not have the contractor make the necessary adjustments. Tape would still be needed for the seam that is above the door that we can't see in the pictures. Do you feel that part of the seam was properly done? There is also an indentation on the edge of wall board for the tape that might have been easier to fill with tape instead of just joint compound that shrinks and could crack.
Here's a few options I can think of.
If the wood is a bit thicker than the drywall, you could use a router to remove some of the material on the back side of the lowest plank (may require installing an additional plank, or extending the drywall). Then allow the lowest plank to lap over the drywall. Make sure you leave enough of a gap between the two materials, to allow for expansion and contraction.
Another option would be to use a transition strip, like the ones commonly used in flooring. You'd use T-molding if the materials are even with each other, or a reducer if they're not.
A simple 1x4 like the previous owners had, or a more decorative piece of molding could be used.
Best Answer
You can do what you like unless local codes require otherwise.
It does not have to be pretty, since it will be hidden, but two benefits of bothering to tape and mud the joint (at least crudely) are better fire performance and not making life easier for your insect friends crawling around the house. A third would be somewhat less air leakage.