I love the look of bead board. I think I'd want to get the ceiling checked out just to make sure there isn't a bigger structural issue that needs addressing first. As far as the look, I think if you use a consistent paint finish, you should be able to use the panels on both the ceiling and the walls.

I did beadboard on two bedrooms and one bath to cover water damage on a rental. Still looks great! You can buy it is 4x8 panels and save a ton of $$$ if you're good at caulk and paint to hide joinings.

Thanks so much - much to think about. Since we've purchased a money pit, we are just trying to keep our heads above water.

I agree with Emily's suggestion to first investigate structural issues and address those if needed or at least be aware of what you're dealing with. Deferred maintenance can become a bigger and more costly problem. Once you're making an informed decision, I think beadboard is a wonderful solution!

Yes, I agree - if you are planning on staying there for any amount of time, please have this checked out by a local trusted contractor. If you are going to cover it up with wood anyway (which I think is a WONDERFUL idea) then you are at no loss except for peace at mind. I do have to say (and no one take this personally) I had a structural engineer go over to a 100 year old house and he literally told them to tear it down because it wasn't structurally sound (20 years later it's still standing). Sometimes, well meaning advice can send you (and your wallet) over the edge. Finding a good contractor is one of the best things you can do and move forward from there. Best of luck!

Since you stated the ceiling is wavy and not sagged, what you are most likely looking at is the original joist 2 x that were not crowned properly. As these boards dry they cause a wavy pattern in the ceiling. The solution is to run 1x spruc furring strips perpendicular to the joist and fir out with a string or laser level. This will give you a flat ceiling. The most cost effective ceiling material is 1 x 4 T& G spruce. You will want to use couple coats of semi transparent white stain on the front before sealing the backs and installing. (sealing is to avoid water staining and a 4 mil poly vapor barrier should be used on the level ceiling before the 1 x is installed) Give the existing crown in the room, I would come off the walls about 13" before I start the new level ceiling to allow you to do a reverse tray look. I would also add a continuous strip of led light tape to the inside edge of this tray to light the existing trim.

My advice is to do hire a structural engineer (with a limited scope). It will only cost you a few hundred dollars and you need to know what is going on with the foundation and the walls. If the structural engineer says, "No Worries", then you may have a simple issue of construction defects. Maybe they didn't crown the joists right, maybe they put 1/2 in. drywall, instead of 5/8 in drywall. How many beams do you have? Re-drywalling the ceiling would not be exhorbitantly expensive, you could do the labor yourself.

To answer your question, beadboard on the ceiling would not devalue your house or detract from it in anyway. I think it would look really nice. The real question in my mind is why are there already beadboard panels or tongue and groove on the walls? What else has been covered up? Was the previous owner trying to hide serious structural issues? I would have a contractor and a drywaller in there to bid on the job, they could tell you also why your ceiling is wavy. They might advise a structural engineer as well.

Re-Drywalling the ceiling and correcting the flaws might be cheaper than beadboard and it's not that complicated.