RC hung ceiling drywall where inside out wall meets.

I looked but did not find a thread or link for this instance. Sorry if this is redundant to anything here. I was wondering how a seal could be formed if walls are made similar to inside out walls (i.e. sheet rock on outside of framing, treatment inside cavity) and ceiling is drywall hung from building joist (by channel or otherwise). At the location where these two surfaces meet I cannot picture where a bead of caulk or other seal can be made. Could the ceiling drywall be sealed up against the top plate stud of the wall with caulk and backer rod? Does using these two types of construction (soft walls and hard ceiling) even make sense? Has anyone done this? Thanks. PS- question for this build http://johnlsayers.com/phpBB2/viewtopic.php?f=10&t=17389 - if I should keep all questions on that thread just moderate me (beraide, ridicule, etc).

At the location where these two surfaces meet I cannot picture where a bead of caulk or other seal can be made.

(John discussed this on a thread here someone, but I don't recall where: But I happened to have a copy of his drawing saved locally.)

- if I should keep all questions on that thread just moderate me (beraide, ridicule, etc).

Consider yourself duly "moderated, berated and ridiculed"! :) Yup, it's better to keep all your posts about your build in one place, on one thread. You'll thank yourself later, a few months down the line, when you go searching all over the forum for the answer to a question that you just KNOW you asked, but don't remember where.... :) - Stuart -

Ok. Thanks on both scores. I saw this detail and there is another showing detail of inside out wall meeting a right side out wall. I was wondering more about resilient channel mounting on ceiling and inside out wall. The drywall on ceiling would need have the first seal at top stud i guess.

"Could the ceiling drywall be sealed up against the top plate stud of the wall with caulk and backer rod?" Yes.