Are there leaks, are there cracks, are you sure it's drywall and not plaster on wood lath?

I am still removing tiles...not really sure what I am getting into but the living room is 800 sq ft. so I have a ways to go.

The homeowner disclosed that about the roof leak.

For example, if it's water damage on the tiles, you should fix the leak before attempting to fix the ceiling.

After that, what you do depends on what exactly is wrong with the old ceiling. If it's just nail holes from the 1x2's, you're talking about a little spackle and some paint.

If the existing ceiling is damaged by something like a leak, but the damaged area is small (about 3" in diameter), remove the old material, and you can construct a patch that is supported by the old material. If you happen to be this lucky, I can explain how to do that in another post.

If there was a leak, it probably damaged a larger area. You'll need to replace the damaged ceiling, and then get out the paint. To fix it, remove the drywall/plaster in the damaged area. Then remove additional drywall/plaster until you have a roughly rectangular area that ends about 1/2 way through the ceiling joists (the wood that forms the structure behind the drywall/plaster). Your goal is to create a seam between the old and new drywall and have both sides of the seam anchored to the structure of the house. If most of the ceiling is damaged, it may be easier to tear down all of it and start over. If the existing ceiling is plaster, consider ripping all of it off if 1/4 to 1/2 of it is damaged - it's harder to repair than drywall.

From there, you need to cut a new piece, or pieces, of drywall to fill the hole. If the existing ceiling is drywall, then it's probably 1/2" drywall and you can just use new 1/2" drywall to end up with a flat surface. If the existing ceiling is plaster, then it will be much thicker - probably 1". Since you need the new material to line up with the old, you'll need to use 1/4" drywall strips on the joists, followed by a sheet of 3/4" drywall to fill the area.

Next, you'll need to tape the joints with drywall tape. For a repair like this, I recommend the fiberglass mesh tape. It's much easier to use than paper tape, especially overhead - it's self-adhesive, while the paper tape is not. Pros like paper tape because it's faster to end up with a smooth final surface, but they have the practice to make it work well.

Then you'll need to smooth over the tape and any other irregularities with drywall compound. There's two kinds - water based or cementitious. Water-based is available already mixed in a tub, or as bags you mix with water. You will have to wait at least overnight for the water-based versions to dry and harden before sanding and applying the next coat.

Cementitious versions will advertise the drying time on the bag, and are only available as powder. You mix the powder with water, spread it on the ceiling, and then wait the time on the bag. Do not get the 5 minute version - that's only good for either very experienced people, or very small areas. You'll need to wait at least double the time on the bag before sanding - the time on the bag is only the working time. It is better to wait longer.

You'll be putting on 2-3 coats of drywall compound. So don't try to fill any gaps in your first application. The compound will be too thick, and not dry properly - it shrinks when it dries, and you'll be left with a more difficult problem to solve in later coats.

So apply a coat. Let it dry. Sand it mostly smooth. Then apply a second coat. Let it dry. Then sand it smooth (note the loss of "mostly" from the previous coat). Repeat until you have a flat-looking ceiling.

Finally, if all that seems like way too much work, you could have an acoustic ceiling sprayed on the old ceiling to cover the damaged stuff. It looks like cottage cheese. It only comes in white. If you paint it another color, it will be very annoying to remove in the future. And it's a really, really, really bad idea to try and apply it yourself - you really want to hire it out if you're going for that solution.

I am still removing the ceiling tile--I honestly had expected a grid and was just going to replace the damaged tile. This was more than I had anticipated...but very helpful!

Try to avoid sanding. Sanding is only needed if you can't apply it well.

I got through college doing remodel jobs and got pretty good with joint compound and plaster, never ever used sandpaper.

Put it on carefully enough and there's no need.

Also, with the tape, put some mud down then the tape then some more mud over the tape and smooth it out.

If the tape doesn't get moist throughout it'll give your trouble.

800 square feet, that's a big room!

That's what you do with paper tape.

If you use the fiberglass tape, you do not want to put any mud under it. You stick it directly to the drywall (which is why it's self-adhesive) and then mud over it.

If using the pre-mixed compound, do the first coat with the green top mix - it's stronger but hard to sand. Then top it with the blue top mix. That blue top isn't tough enough - especially with fiberglass. Use paper tape with the blue top.

The pros do the final top with that pre-mixed yellow stuff that comes in a box. Goes on like butter. Or so my brother/partner has been bitching to me on this ceiling repair we are working on.


I prefer to use the bag mix (hot mud) and mix it myself and go over the mesh tape. 90 minute mud - easy sand. I've had that blue top pre-mix get hairline cracks and had to go back and dig out the joints and re-mud with hot mud.

The hot mud is stronger. I had a pro on JLC (a pro forum) say the fiberglass tape is not needed if you use hot mud. I don't know about that. Seems risky.

Hot mud and fiberglass tape is the way to go for a novice. IMO. Paper tape can be a little tricky for a novice.

Like you said up-thread - many coats. Less is more. Apply a coat and take off the excess. The first 2 or three coats just fills in the gaps (and the shrinkage) as you proceed. I used to do 2 coats and a feather coat but now I do 3 coats and a feather coat - with knocking down any "boogers" with a taping knife in between coats.

The biggest mistake is trying to get it "perfect" on your first coats. The first coats just set up a flat surface. The you can do a final feather coat.

Last edited Wed Apr 10, 2013, 11:46 AM - Edit history (1)

I think you have to look at it through what you don't know before you go into how you will go about
fixing the problem. It comes down to this- if you are going to venture into it, you first remove the drop ceiling -the 1x's 2's carefully and from there see what you got. Even before you remove those 1x's 2's you should have a pretty idea of what you are up against in so far as the damage to the sheet rock .

The first question that comes to mind is why is there so much damage to the drop ceiling tiles ?
One poster mentioned a roof leak- that is possible. And again is there a second story ?

If it were me ,I would want to know why that drop ceiling was installed -to know that removing it will tell the story.

If you find the sheet rock ceiling is warped due to water damage the only way to fix that is to
demo the ceiling and hang new sheet rock.

At this stage in it you cannot be advised until you know what you are up against-,removing the drop ceiling will show you what the underlined problem is'.

After you know what you are up against ,that is when you go into the corrective measure stage in your project.

What it comes down to is you want to know or you don't. The previous owner decided to do the drop ceiling -cover the problem up- easy-cheaper and less of a mess.

It does you no good to be advised on how to apply tape and mud until you know what the extent of the problem is. demo is the first phase of your project. After that you will know what you are up against.

Again if the ceiling is warped badly due to water damage or some such issue,you will have to demo it and hang new sheet rock.

And, bin sober made a point about the application of tape and mud- there are no short cuts-you always sand between applications of the mud. There is a method and done correctly you simply swipe over the areas you apply the mud -pole sanders are good for that job. You can buy a apparatus that attach's to your industrial vac. that way all the sanding debris is sucked up.
On the final sand you must feather it all in. But you are not at that stage in your project.

A lot of contractors like that u mix mud- hot mud.
However there is a mixing technique and experience applies.Ready mix if perfectly ok for the beginner. There is a new product out for the final application of the mud- it is pre mix and a low or no dust . I used the stuff on a job in a office building recently and it did surprise me that the stuff does what it says it does. The dust falls straight down and does not travel.

You get sheet dust,debris traveling through a house and that is a cleaning nightmare.
The new stuff is great for repairs- the debris falls straight down and does not travel. It is amazing.

We did this with my brothers large living room. Get sheets of luan or 1/4" plywood , stain or paint them, brad nail them over 1x2s Cover the abutted seams with contrasting stained/painted 2x4s. We used stain it really looked good.