# plaster ceiling is sagging



## MarkJames (Nov 25, 2012)

While doing a plumbing repair, I found that the plaster ceiling is coming off the joists and about to fall. It's 1/4" plaster over 1/2" wallboard, and the area that it's "hanging by a thread" is aout 8' x 8'. The gap between the joists and the wallboard base is about an 1" at worst (a lot). These are 9' ceilings and the sag was almost not noticed from the floor level.

What would you advise as a repair? I'm thinking about pre-drilling and countersink, so that some long screws could keep it in place (with the sag), but from falling. Or, as an alternative, pushing it back up against the joists (while existing drywall nails are still in place), and then refastening. Thoughts either way? (Paint crew is on hold for this house.)


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## NickAylett (Mar 12, 2014)

Well cutting out the damaged section and replacing it with new materials is usually the default answer, but I may be able to help you find another solution, If that is not an option. 

Let me ask some questions about your project:
1) to get some things straight, how old is this house? 
2)When you say plaster, do you mean good old fashioned cement or modern drywall compound (mud)? When you say wallboard do you mean modern drywall or something else. 
3) What is the area of the room? 

Provided you don't want to cut out old sagging material, and the area is not too large, I propose you attempt to Jack up the sagging ceiling and hang new drywall over it. The way I would do it is to snap on the ceiling the precise location of each joist, hang 7/16" OSB and screw it on 6" or tighter pattern. This will take care of your sagging problem forever. Carefully consider your screw length. Then simply hang new drywall over the OSB. 

Hope this helps.


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## Big Shoe (Jun 16, 2008)

It sounds like you are/may be opening a big can of worms.

It may have been that way for years. Sometimes the ''sag'' can't be lifted. Trying to hoist it back up may work. Make a couple big ''T's'' out of 1x4's longer than the desired ceiling height. Prop up the ceiling and add new screws. Leave props in as long as needed. (This may cause spider cracks) 

Or you may need to tear out and redo area. Or just leave it alone.

Good luck and keep us posted. :thumbsup:


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## MarkJames (Nov 25, 2012)

NickAylett said:


> Well cutting out the damaged section and replacing it with new materials is usually the default answer, but I may be able to help you find another solution, If that is not an option.
> 
> Let me ask some questions about your project:
> 1) to get some things straight, how old is this house?
> ...


(edit: house built in 1936, sorry). This is in a large foyer, 9' ceiling w/ crown molding, roughly 10' x 12', and the sag extends from the front door to a centered light fixture. I suspect that light fixture is even holding it up somewhat. 

I am calling it plaster, as I understand it. The 3/4" wall material is a two-part "sandwich", comprised of a white finish coat (about 1/4") and a greyer, heavy wallboard material (1/2"), not drywall, more like a heavy mortar material that eats blades. Just guessing dimensions, but these wallboards are roughly 16" x 48" each. Above this ceiling are two bathrooms, so lots of mortar crumble in the ceilings for added pleasure. There are no signs of water damage, so it's just the weight of the ceiling over time that has pulled it away from the joists.

Although a small area, pulling it down is not in the cards this time. If we can at least stabilize it, that's the minimum plan. They are drawing the line on a replacement, due to too many other "surprises" that we are also addressing.


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## MarkJames (Nov 25, 2012)

Big Shoe said:


> It sounds like you are/may be opening a big can of worms.
> 
> It may have been that way for years. Sometimes the ''sag'' can't be lifted. Trying to hoist it back up may work. Make a couple big ''T's'' out of 1x4's longer than the desired ceiling height. Prop up the ceiling and add new screws. Leave props in as long as needed. (This may cause spider cracks)
> 
> ...


Yup, it's a can of worms. So T's, a little nudging, and long screws will probably be the plan. It's just such a big bubble.


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## ranteso (Nov 11, 2010)

I deal with older homes quite often. Here are the three options I give to the homeowner. 

1. Rip it out and install new gypsum board. 2. Install 5/8" gypsum board over the existing ceiling. 3. Walk away.


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## Sir Mixalot (Jan 6, 2008)

I would tear that section down and replace it with drywall and shim as needed to get it flush with the existing plaster ceiling. Next mud new seams and skim out the rest of the ceiling. :thumbup:

If the homeowners don't want to do that and just want you to put a bandaid on this plaster ceiling problem. Definitely explain to them that this is a dangerous situation and it could fall and possibly hurt someone at anytime. Then write a separate change order for this ceiling repair explaining the potential dangers and get them to sign it releasing you of any responsibilities. :thumbsup:


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## MarkJames (Nov 25, 2012)

Rrrrr...sometimes I hate it when I know you're right. Thanks. :thumbsup:

But in a strangely liberating way, since I know it's probably getting ripped down, I can also do a little experiment to see how it goes.


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## Sir Mixalot (Jan 6, 2008)

If you do bandaid that ceiling, definitely use some plaster washers.

Like these:









http://homefixated.com/ceiling-buttons-aka-plaster-washers-help-tame-your-sagging-plaster/


> I wish I had known about these ceiling buttons, also known as plaster washers, a few months ago. That’s about when part of our kitchen ceiling collapsed during some remodeling work. Thankfully no one was under it when it came down, because I am pretty sure 80 square feet of plaster would hurt. Apparently I am not the only one with loose plaster woes. These plaster washers are used to hold up sagging ceilings. They are countersunk in the middle for a drywall screw and have perforations to provide a “key” for your patching compound to hold on to. Plaster washers are available in the standard 1 inch diameter and the new and improved 1-1/4″ Plaster Washers which are stiffer to hold more weight per screw.


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## Xtrememtnbiker (Jun 9, 2013)

You can tell them about the friends of ours who became clients when their FR ceiling fell in on them. Thankfully the wife suffered a broken toe and that was it.

It was about 100 sq ft of plaster ceiling exactly like yours.

We tore down the whole ceiling, furred joists to make everything flat and hung drywall.

Even just when demoing the rest we were talking about the weight of it and it was good no worse injuries. It's not really something to kid yourself about, or them, that someone could get seriously hurt by it.


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## Frankawitz (Jun 17, 2006)

Well I have done plaster for 28 years and you said house was built 1910 -1920's but you say it has wall board so this tells me the ceiling has been repaired, if it was 1910 1920 it would be wood lath wire mesh corners, so this also says water damaged is there a bathroom above or was the roof leaking. As for pulling it back up Good Luck:laughing: that base coat is Portland mix it ain't gonna move with out breaking and cracking. Rip it out put up 5/8 then just base coat skimcoat call it done. Another thing try not to break crown cause it is plaster and if you damage it it will have to be repaired using a number of different ways. Good Luck


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## MarkJames (Nov 25, 2012)

Frankawitz said:


> Well I have done plaster for 28 years and you said house was built 1910 -1920's but you say it has wall board so this tells me the ceiling has been repaired, if it was 1910 1920 it would be wood lath wire mesh corners, so this also says water damaged is there a bathroom above or was the roof leaking. As for pulling it back up Good Luck:laughing: that base coat is Portland mix it ain't gonna move with out breaking and cracking. Rip it out put up 5/8 then just base coat skimcoat call it done. Another thing try not to break crown cause it is plaster and if you damage it it will have to be repaired using a number of different ways. Good Luck


Actually 1936. Sorry about that. Whole house has this stuff, so assuming it's original. Two bathrooms above (original) on mudbeds over lathe. the crown is wood, fortunately. That looks like a later addition.

Many homes built in the late 40's around here have the same stuff (Arlington, VA).


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## Frankawitz (Jun 17, 2006)

Mark OK then you have rock lath it's 3/8 plaster board 16"x 48" then they mixed Portland cement sand lime for scratch coat then plaster for putty coat, I've worked in homes built in the 1930's and crown was plaster, but it is what it is:thumbsup:


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## hdavis (Feb 14, 2012)

If you try to bandaid, skip the plaster washers - you'll have to put about 2 billion in there, and then skim and blend the whole ceiling. Also, don't push it back up with plain Ts, use ~1/2" ply or osb cut to a manageable size. Ts will 100% bust it to bits. There are commercial products for plaster repair - I don't know if they'll work on this. Basically a bunch of holes are drilled, then conditioner is squirted in, and then an adhesive foam is put in and everything is pushed up tight..


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## rogerhattman (Jul 6, 2008)

1" is alot of drop. I would use long drywall screws and anchor plates (https://www.warehousebay.com/catalo...box-/?osCsid=0ef0b460025d7d11d8e720b1f02ebaf1) or large plaster washers to temporarily secure the ceiling. After securing it, if you can tighten the screws and bring it back into place, do so. Permanently attach with countersunk #8 woodscrews and plaster washers (pics posted by Sir Mixalot). I would not rely on glue here, but a little thin acrylic applied in the hole before you insert plaster washer would help the strengthen the base. Make sure the plaster is not water damaged. If it is warped from water, definitely remove.


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## NickAylett (Mar 12, 2014)

Those plastic anchors look pretty wimpy. I have not used them, but they don't look like you could use them to jack up this plaster board & cement. BIG SHOE stated that the material is likely to "Spider Crack". He is absolutely right. The ceiling is likely no longer flat, and forcing it straight in an hour's time is going to break it. A valid question is, would you rather cover yourself in case something goes wrong? 

I go back to my original idea: Find the floor joists and mark them on the wall. Hang OSB with long screws (leaving them barely snug at first and then slowing jack the ceiling up, and ultimately add many screws to make sure it's bulletproof. Hang 5/8" Drywall and finish like new.

Minimal mess, Flattens out the ceiling, Makes for a good solid surface. 

Also consider, if you pull that down will there be any asbestos related products in there. Not just a scare tactic. That's stuff is really bad news and you could have it.


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## overanalyze (Dec 28, 2010)

We have a lot of homes built in the late 60's and 70's with plaster ceilings with ceiling cable heat. The cable heat causes excessive dry out of the lumber causing the nails to loose their hold and ceilings to fall. Very scary if that happens and dangerous. 

You know what to do. Tear it down and replace. Also add some screws to the area around that you leave.


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## EthanB (Sep 28, 2011)

I usually try to rescue plaster walls but ceilings should be demoed and patched. There's way too much risk of chunks falling after a repair and I'm not comfortable leaving a product that may result in chunks of cement falling on people. Even if you attach it with screws and adhesive every 4 inches a half pound piece could still fall. On top of that, demo and patch is probably going to take the same amount of time.


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## Big Shoe (Jun 16, 2008)

Damned if you do.........Damned if you don't.


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## hdavis (Feb 14, 2012)

Big Shoe said:


> Damned if you do.........Damned if you don't.


This seems to be one of those that they don't have money to do something safe with it, so maybe just offer to put OSB or ply up not even tight to the ceiling to catch anything that might fall.


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## MarkJames (Nov 25, 2012)

Well, I did. Demo'd the whole ceiling because we decided to check all the drains anyway. Hardboard on the floors, demo hammer with chisel bit to cut some rectangles as you go, etc. Easy.

Now I have to deal with the mess. Probably I'll try a bagster this time around.

EDIT: Bagster pick-up charge with tax is $163.24...I thought these things were a deal. Maybe only to save time.


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## Big Shoe (Jun 16, 2008)

EDIT: Bagster pick-up charge with tax is $163.24...I thought these things were a deal. Maybe only to save time.

A lot of my customers think that $40 they pay for the bag cover the pick up too. :laughing:

It is cheaper to get a small dumpster dropped than two bagster pickups.


And thanks for the update. :thumbup:


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## D.E.P.S. (Aug 3, 2013)

Sir Mixalot said:


> I would tear that section down and replace it with drywall and shim as needed to get it flush with the existing plaster ceiling. Next mud new seams and skim out the rest of the ceiling. :thumbup:
> 
> If the homeowners don't want to do that and just want you to put a bandaid on this plaster ceiling problem. Definitely explain to them that this is a dangerous situation and it could fall and possibly hurt someone at anytime. Then write a separate change order for this ceiling repair explaining the potential dangers and get them to sign it releasing you of any responsibilities. :thumbsup:


Right on. I'll use some buttons on ceilings where there is a little localized sagging near a crack, but they cannot be trusted to pull in a large area. The plaster will keep failing and end up landing on sombody's supper table.


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## Sir Mixalot (Jan 6, 2008)

D.E.P.S. said:


> Right on. I'll use some buttons on ceilings where there is a little localized sagging near a crack, but they cannot be trusted to pull in a large area. The plaster will keep failing and end up landing on sombody's supper table.


Agreed. That's what I told the OP.
But he said replacement wasn't going to happen. So, I was just trying to help the best I could with that plaster washer suggestion. :thumbsup:


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## MarkJames (Nov 25, 2012)

Sir Mixalot said:


> Agreed. That's what I told the OP.
> But he said replacement wasn't going to happen. So, I was just trying to help the best I could with that plaster washer suggestion. :thumbsup:


We eventually came to our senses.  First it was about cost, but then it became more about peace of mind, in that we could also get a better look at the plumbing work before it got closed up. 

I even thought of replacing just the bad part, but figured who wants to feather all that? So I took down the crown (temporarily), pulled it all down, cleaned up the edges, and we'll go from there. A good feeling to do it right.


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## D.E.P.S. (Aug 3, 2013)

Sir Mixalot said:


> Agreed. That's what I told the OP.
> But he said replacement wasn't going to happen. So, I was just trying to help the best I could with that plaster washer suggestion. :thumbsup:



Nice website by the way.


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