Moved in 3 years ago. Beach house up on stilts, in Rockport TX. which backs up to Salt Lake, probably help if you google map that area. I do not know the history on the house, but it appears that the downstairs finish out was not part of the original build. That downstairs (+/- 100sq.ft) is climate controled with 2 split air units keep temp around 74.

Yesterday I noticed the ceiling (sheet rock) is sagging, pulled away from nails or screws and has water stains.

I’m guessing condensation between the ceiling of the downstairs and the floor of the upstairs. No bathroom or kitchen directly above affected area.

Any suggestions on what may happing? If it is condensation what is the corrective action.

Thank in advance.