Spot Repair Water Damage in Ceiling

[sandoran]

June 12, 2021 - I have a house that dates back to 1870s. It was renovated into 4 apartments.
Please see photo of ceiling in one small bedroom
Had a roof leak and part of the ceiling got wet and came down.
I don’t want to take the entire ceiling down. I believe there is plaster and lathe above this.
Can just the panels between the wood slats - that are wet be removed and replaced - and leave all the wood structure that is there now? Then Install new drop ceiling on existing wood slats – or the Styrofoam tiles which you can paint and stick to ceiling? I am not sure what the material is that is wet/stained – seem like paper or paint or cardboard – can’t imagine it cannot be taken down carefully in the one section. Thanks for any help!

[1918ColonialRevival]

Just to make sure I'm understanding the question correctly, you're asking if the remaining acoustic tiles can be taken down, the wood strips they were attached to kept, and new tiles put up?

If that's the case, it shouldn't be a problem as long as the wood didn't warp. If it did, cut out the warped section and replace that length of wood.

If it were me personally, I'd take down the acoustic tile, wood strips, scrape and stabilize the plaster ceiling, and skim coat it.

[Gothichome]

What are your those blobs? Are you restoring the home as a private residence one again? Oh, and welcome to the District. I see no issues with just removing the tiles and letting things dry out. Depending on the condition of the plaster you have two options, if the plaster has lost its keys it will need to come down and replasterd (it will fall down by itself with out strong keys) or I the plaster is still firmly attached to the lath a plaster skim would be a proper fix as Colonial suggests. If the plaster has lost too many keys, you can always drywall using the existing strapping, this an option I chose for two of our ceilings.

[mjt]

Some of the blobs look to be holes in the plaster with fiberglass insulation poking through.

[phil]

I'd take down the acoustic tile. leave the strapping and install new drywall on the ceiling. use the big sheets, less joints to fill all the tiles do is date the place to the early 70's or so. it was a fast way because no filling was required.

I had them in my living room and they were attached to a metal track . I pulled it all out and finished the ceiling flat.
mark where the strapping is on the walls so you know where they are when the drywall is in place. check if it's flat. If not you can cut strips of paneling or something to use as shims. if you want ceiling lights then install the pots before you drywall. I did some extra skimcoating to get it more perfect and that way i could use a shinier paint without dips and sags showing. ( kitchen and bath) so it's more washable. I dont thing they contain asbestos but you could confirm with a lab test. if you run into filler then be careful because a lot of that 70's drywall filler was asbestos and you know this was done during that era so they may have also done other work nearby with asbestos drywall mud.

[phil]

Some of the blobs look to be holes in the plaster with fiberglass insulation poking through.

I thought maybe it was their attempt at blocking / cushioning sound. it could be taken off and that would leave 3/4 or so so you could put some ISO board in there and increase the R value a tiny pit. but it's a dead air space anyway..
you can also use beads of green glue on the strapping to cut down sound. frankly I'd just drywall over the mess and move forward. saving that plaster would be ambitious and then the ceiling would end up flat, same as drywall. you might raise the ceiling 1/2 inch or so or more if you want to demo all that plaster , but you'd work so hard for that little bit of headroom it wouldn't be really worth it. It's an extra day with a hammer smashing it all out and a lot of mess. I wouldn't go there unless the ceiling height is that important. It's a lot of work for little gain. Yea possible to learn to plaster a ceiling with traditional methodology , that is more authentic. even more work though. it would increase the echo. in the end I just dont see the gain being worth the pain going that route myself but of course it is up to the owner to make those decisions.

Id use the green glue for what that's worth. just beads on the strapping. it wont add a lot of cost. this is sound insulation, not glue. it wont bond the drywall to anything, it just helps block sound transfer.
https://www.greengluecompany.com/

the way it's normally used you drywall then put beads of it and more drywall and that helps block sound. some do several sheets or use soundproof drywall. I used the expensinve soundproof drywall in my living room it because i'm near a busy street and I couldnt; hear my TV. I can crank my stereo and barely hear it outside the house. you might want that if you had a kid with a drum set in the attic, if there is a room above there that is usable. the tiles were just a cheapo 70's style upgrade. It was common as it did improve the acoustics but its ugly. you could hang an acoustic ceiling like in an office building, but that's ugly too.

the soundprof stuff is really heavy so I wouldn't use that on the ceiling.

[sandoran]

Thank you! Will post BEFORE / AFTER Photos.

[PaulJohnson]

Suggestion - before any repair work you will want to make sure all of the moisture is gone. Trapped moisture can cause lots of issues in the future if not addressed - deterioration of what plaster is left , as wells, mold are two examples.