Warped ceiling

Firsthomemaryland · Aug 14, 2024

Over a year ago our contractor installed this 1/2" lightweight gyp ceiling on joists 24" o.c. The insulation wasn't installed prior so they had to go into the attic to do it after the ceiling was up. They then placed foil backed insulation wrong side up so had to go in a second time to flip every piece. This is what the ceiling looked like afterwards. Given that the lines are not 4' apart I assume that the ceiling was warped by deflecting joists and it's not just visible seams. I didn't even think that could happen. Seems a reasonable expectation that someone could go in an attic without destroying the ceiling.

Is there anything that can be done to improve it short of replacing? I'm afraid that any sanding and refinishing will just further weaken the drywall making it worse the next time someone walks on the joists.

Snoonyb · Aug 15, 2024

An interesting regional or trade methodology.

In my practice, both residential and commercial, 24" framing members, always, were addressed with 5/8" material, and insulation was always installed first.

Firsthomemaryland · Aug 15, 2024

I called that out and the contractor told me he would only use 5/8" for commercial. Hard lesson. I hired a crappy contractor and here we are.

Do you agree that the board has been "bent" or is it just coming loose around the joists? It is sort of hard to tell if the lines run along what would be the edges of board.

Do you think any can be done for it or do I just ride it out until it falls on us while we're watching TV one day?

Snoonyb · Aug 15, 2024

Although the timing is unpredictable, there's a thrill to be had...................

Were it I, I'd take it down and reinstall. 5/8" lightweight is about 20lbs lighter than standard.

Here's some discussion; https://www.thespruce.com/ultra-light-drywall-1821478#:~:text=A 4 x 8-foot sheet of standard 5/8,by ultralight can be significant.

DFBonnett · Aug 15, 2024

Rule #1... 24" centers requires 5/8". Rule #2... See rule #1. Over many years as a decorating contractor I ran into many instances when some hack "contractor" used 1/2" when 5/8" was required and sag between joists or trusses on 24" centers was visible.

PJB12 · Aug 16, 2024

It's hard to see from the photos, FirstHomeMaryland, but it it possible that the contractor used nails and they are coming loose? Maybe gently push up on a sag and learn if the sheet moves up. If so, your repair will be easy by lifting while screwing in with coarse thread drywall screws.

If you do remove the ceiling and want to use 1/2" lightweight, you could put "strapping" on 16" centers. Strapping is made of 1 x 3 strips screwed to the joists, but perpendicular.

You'll put them on either 16" or 12" centers. It is the common practice in the New England area. This also helps prevent cracks if the joists above flex a bit.

Paul

Firsthomemaryland · Sep 1, 2024

Thanks for the suggestion, Paul. I was looking back at the progress photos and it does look like the bends line up with the edges of the boards, so it seems plausible that is what is occurring.

PJB12 said:
It's hard to see from the photos, FirstHomeMaryland, but it it possible that the contractor used nails and they are coming loose? Maybe gently push up on a sag and learn if the sheet moves up. If so, your repair will be easy by lifting while screwing in with coarse thread drywall screws.

If you do remove the ceiling and want to use 1/2" lightweight, you could put "strapping" on 16" centers. Strapping is made of 1 x 3 strips screwed to the joists, but perpendicular.

You'll put them on either 16" or 12" centers. It is the common practice in the New England area. This also helps prevent cracks if the joists above flex a bit.

Paul

Ron Van · Sep 5, 2024

Wow! I know from experience that imperfections in ceilings look worse under certain lighting conditions and angles. The light in your photo is highlighting the bulges. But, to me, the imperfections look more like bulges rather than sags. Is this true? It's like the sheetrock was screwed to joists that weren't level or smooth?

Firsthomemaryland · Sep 5, 2024

Ron Van said:
Wow! I know from experience that imperfections in ceilings look worse under certain lighting conditions and angles. The light in your photo is highlighting the bulges. But, to me, the imperfections look more like bulges rather than sags. Is this true? It's like the sheetrock was screwed to joists that weren't level or smooth?

To be fair, this is true. When it's cloudy in a certain light it's not too noticeable. I think you're right that these are bulges because I went back to photos I took during construction and the bulges kine up with the seems. I'd also bet the joists weren't level. We've found some pretty sketchy work the previous owner did all around and this was an addition they put on the original house. Unfortunately, until they went back up there (and especially the second time) it was pretty smooth. So evem though I can't feel any flex when I push on then there may be something to them having only nailed in the panels and screwing them in more firmly could help. Really don't want to take down the ceiling...

PJB12 · Sep 6, 2024

Firsthomemaryland said:
To be fair, this is true. When it's cloudy in a certain light it's not too noticeable. I think you're right that these are bulges because I went back to photos I took during construction and the bulges kine up with the seems. I'd also bet the joists weren't level. We've found some pretty sketchy work the previous owner did all around and this was an addition they put on the original house. Unfortunately, until they went back up there (and especially the second time) it was pretty smooth. So evem though I can't feel any flex when I push on then there may be something to them having only nailed in the panels and screwing them in more firmly could help. Really don't want to take down the ceiling...

Your idea of sending new screws in, even though there's no flex, sounds like a very good plan.
Perhaps make a Tee from wood to try to push an area up while screwing. Make it a little longer than the ceiling is tall so you can wedge it in. The Tee is a piece of 2 x 4 (or preferably wider) wood screwed to the end of a 2 x 4.

I had a plaster ceiling that was wavy, but didn't flex when pushed on as hard as I could push. Using the Tee pushed it back up while I screwed. (I expected that it wouldn't because plaster keys surely would have been broken and in the way.)

Paul

PJB12 · Sep 6, 2024

Ron Van said:
Wow! I know from experience that imperfections in ceilings look worse under certain lighting conditions and angles. The light in your photo is highlighting the bulges. But, to me, the imperfections look more like bulges rather than sags. Is this true? It's like the sheetrock was screwed to joists that weren't level or smooth?

If it turns out that the bad areas are bulges instead of sags, as Ron Van mentioned, maybe the finisher just did a poor job of mudding. Or, maybe (as you mentioned) the joists aren't in plane.

Maybe scuff sand any glossy paint, then re-mud really, really wide. All drywall butt joints have bulges, but we don't notice them because the mud is wide.

I'd mud one side of each bulge at a time and let the compound firm up. Setting mud is ideal for this. It comes in 5, 15, 20, 45 and 60 minute working times. For butt joints, I sometimes end up using up to 24" trowel (instead of a knife) if the joist or stud is way out of plane with its neighbors.

For painting, ceiling paint is super flat so imperfections aren't noticed as readily.

I may be wrong, but that's how I'd attack it if they are mud humps.

PJB12 · Sep 6, 2024

I apologize for not thinking of this earlier:
An easy way to 99% confirm if the drywall is loose from the joists or the warps are simply bulges, is with a small diameter drill bit or a piece of stiff wire- or even an ice pick or awl.

Poke the tool slowly through a bulge.

If it has resistance all the way until it stops, the waves are the bulges that Ron Van mentioned.

If the bit all of a sudden goes is easily for a short distance and stops, there is a gap between drywall and the joist.

If the bit suddenly goes in easily and keeps going easily, the bulge isn't under a joist.

Warped ceiling

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