Drywall seams question

[KurtB]

I'm wondering if anyone can help with this. I've removed popcorn from several the ceilings in our house. Once removed, it appears the tape job most likely wasn't up to fully finished standards for painting. I guess because of the popcorn being sprayed on. So I've gone over the joints between the seams and the ceiling/wall junction with USG Plus 3 compound prior to painting the ceilings. Two coats with sanding in between and after.

This has worked very well everywhere but the kitchen ceiling. In that location after about 1 year I'm noticing a slight bulge in the tape lines between the joints running the width of the ceiling. It's not really visible because the Ultra White ceiling paint hides it very well. I'm just concerned that I may have done something to cause it and don't want to repeat any mistake I may have made. I also don't know if eventually it's going to crack.

I'm wondering if you folks might have the answer to this? Thanks very much for any help you can give me.

 

[flycubs]

Honestly it looks like the tape was bedded with the seam out instead of down. If there's enough mud under it (does it press in?, if not, it's ok), I'd fair it out with additional compound, paint and let the flat white paint do its magic!

 

[Graywolf]

That just needs to be cut out and re-taped.

 

[JimD]

My entire house had popcorn ceilings when I bought it. I took them down by spraying with water and scraping. I usually had to fix up the seams afterward. I think the seams opened up because of at least a couple reasons. The popcorn was helping to hold the tape in place and the water may have seeped through the tape and softened the mud under it. Mostly I could just retape as you have. Sometimes I had to pull the paper tape and reinstall. I use a woven fiberglass tape instead of paper.

I cannot see your crack well but I suspect you will need to remove the tape and reapply if you want the crack to go away entirely.

The premixed mud is drying compound, it sets up when the water goes away as it dries. It is the easiest to apply and sand. But it softens if it gets wet. I like to use setting compound which has paster of paris in it for at least the first coat. It is stronger and water resistant. In a wet area I may use it for all the coats. It is harder so it sands slower but not like wood. It is also easy to store for future use since it comes dry in a bag but usage is less convenient because you have to mix it up right before use. You can apply two coats in a day but you have to wait for it to dry completely before sanding it.

 

[KurtB]

Thanks very much guys. It does feel as if it pushes in. Hard to tell. I attached a more close up picture. i was hoping to avoid re-taping it, but I guess I may have to bite the bullet and get it done. Still trying to figure out why it happened here and not any place else.?

 

[Rwe2156]

Yeah, what I know about it, is if you don't have enough mud under the tape it bubbles.

 

[Oka]

Old Popcorn ceiling usually had Level 2 finish - fire tape and one top coat, pretty rough.

Like Phil mention it could be cut out and retaped if it is failing. To test run a 6" taping blade flat , against the edge especially if there is a little curling and then, if it separates then, chase it until it adheres and cut out the failing section and retape.
Another way to check is to skim over with thinned tape mud (almost like pancake batter) over the seam and watch if it bubbles. Then address those areas.
If you are unfamiliar with sheet rock compound- Joint compound is used for base and 1st topping because it stronger/harder. Topping is less strong, but sands easier so, it is used for the 2nd topping or skim coating. Finally, remember to thin the joint compound with water,especially when it is hot like now. a General rule is add 8 oz water to a new bucket or box to start and then mix thoroughly. then check how stiff or loose and then go from there. A 5 gal bucket can handle up to a qt of water per the manufacturer's recommendation. If it is hot the wall will suck the water out of the mud making it hard to work and, on retaping like this it may not adhere the tape and will bubble requiring rework. Hope that helps

 

[Gotcha6]

When you rework the seams you may also want to use mesh tape instead of paper.

 

[pop-pop]

When you rework the seams you may also want to use mesh tape instead of paper.

Curious as to when is mesh tape is more appropriate than the paper tape?

 

[Rick Mainhart]

Curious as to when is mesh tape is more appropriate than the paper tape?

All old work benefits from the mesh tape. When you apply joint compound to any drywall, the water is sucked out of the compound and into the drywall ... thus the poor bonding between the tape and the drywall. The overcoat of compound hides this lack of adhesion ... for a while.

Paper tape is less expensive, and the pros often use a "banjo" ... a machine loaded with joint compound AND a roll of paper tape to quickly apply both in one motion to the surface ... speeding up the process.

Unless you prewet the drywall (and how much to prewet is not an easy answer), you will have adhesion issues. With the mesh tape, you are pushing joint compound (and water) through the mesh (where it can, that is), and if you push sufficient joint compound into the gaps in the drywall, you are keying the entire joint to the two pieces of drywall. When you see additional water added to joint compound, you are seeing experience being applied to add just enough extra water to wet the joint, but not thin the compound down enough to slump, drip, or simply fall off.

I figure the additional expense of a roll of mesh tape well worth the expense when you look at the hours you will spend applying tape and mud to a wall, letting it dry, and reapplying (in thin coats, thank you very much) to make a nice smooth seam. Oh yes ... and the repair and repainting time you'll save.

The professional drywall finishers may not agree to this, unless you phrase the question "for the casual, untrained DIY homeowner" ... and after the eye-rolling, they'll probably (and reluctantly) agree.

 

[KurtB]

Old Popcorn ceiling usually had Level 2 finish - fire tape and one top coat, pretty rough.

Like Phil mention it could be cut out and retaped if it is failing. To test run a 6" taping blade flat , against the edge especially if there is a little curling and then, if it separates then, chase it until it adheres and cut out the failing section and retape.
Another way to check is to skim over with thinned tape mud (almost like pancake batter) over the seam and watch if it bubbles. Then address those areas.
If you are unfamiliar with sheet rock compound- Joint compound is used for base and 1st topping because it stronger/harder. Topping is less strong, but sands easier so, it is used for the 2nd topping or skim coating. Finally, remember to thin the joint compound with water,especially when it is hot like now. a General rule is add 8 oz water to a new bucket or box to start and then mix thoroughly. then check how stiff or loose and then go from there. A 5 gal bucket can handle up to a qt of water per the manufacturer's recommendation. If it is hot the wall will suck the water out of the mud making it hard to work and, on retaping like this it may not adhere the tape and will bubble requiring rework. Hope that helps

Thanks Casey. That's a big help. I was using the "USG Plus 3" for 2 coats or so because it's easier to sand. I wondered if I should I be using their Green "All Purpose Joint Compound" instead for the first coat over the tape? I think that may be what I was doing in the areas that didn't bulge. Plus the other seams I've covered haven't been as long, hallways and bathrooms instead of full kitchen.

Any advice on choice of tape? I've seen it done with mesh and with paper as I've researched a bit.

 

[KurtB]

All old work benefits from the mesh tape. When you apply joint compound to any drywall, the water is sucked out of the compound and into the drywall ... thus the poor bonding between the tape and the drywall. The overcoat of compound hides this lack of adhesion ... for a while.

Paper tape is less expensive, and the pros often use a "banjo" ... a machine loaded with joint compound AND a roll of paper tape to quickly apply both in one motion to the surface ... speeding up the process.

Unless you prewet the drywall (and how much to prewet is not an easy answer), you will have adhesion issues. With the mesh tape, you are pushing joint compound (and water) through the mesh (where it can, that is), and if you push sufficient joint compound into the gaps in the drywall, you are keying the entire joint to the two pieces of drywall. When you see additional water added to joint compound, you are seeing experience being applied to add just enough extra water to wet the joint, but not thin the compound down enough to slump, drip, or simply fall off.

I figure the additional expense of a roll of mesh tape well worth the expense when you look at the hours you will spend applying tape and mud to a wall, letting it dry, and reapplying (in thin coats, thank you very much) to make a nice smooth seam. Oh yes ... and the repair and repainting time you'll save.

The professional drywall finishers may not agree to this, unless you phrase the question "for the casual, untrained DIY homeowner" ... and after the eye-rolling, they'll probably (and reluctantly) agree.

Thanks Rick. The rationale behind the mesh tape being more fully embedded in the mud made sense to me when I saw it used, especially like you said, for a novice.

 

[KurtB]

I'm wondering now when it comes to the next room I do, if I should go ahead and remove the old tape on the seams and redo it or if maybe using the harder joint compound may solve the problem? Guess I could run some checks on it like Casey mentioned first.

 

[pop-pop]

All old work benefits from the mesh tape…

Thanks for the explanation. Makes sense.

 

[Oka]

TBH- I have found often after scraping the acoustic ceiling if the sheetrock ceiling looks too rough, I'll just re-rock the ceiling with 1/2 making sure I do not match the existing seams. Then, I can start fresh. If I am going top shoot texture on the ceiling then even if the existing is rough I can hide it with the texture.
The main reason taking this kind of approach is, if you want to smooth wall the ceiling, then, the work to do that is just way too much over just re-rocking and starting anew.

I'm wondering now when it comes to the next room I do, if I should go ahead and remove the old tape on the seams and redo it or if maybe using the harder joint compound may solve the problem? Guess I could run some checks on it like Casey mentioned first.

 

[JimD]

Looks like FibaTape is available at the home centers and is similar to what I've been using. Regular mesh tape is very strong but is also kind of thick and I often seem to sand into it getting a seam smooth. FibaTape is thinner so this is less likely to happen.

It is easy to recognize the two types of drywall compound. Anything pre-mixed and sold in buckets is a relatively weak and easy to sand drying type compound that will not be at all water resistant. This material is also sold dry in cubic shaped boxes bought by some professionals, presumably to save weight. The compound sold in bags that look like concrete bags is the setting compound that has plaster of paris. It is stronger and at least somewhat water resistant. It is recommended for at least the first coat over fiberglass tape. You have to put water into the container first and then the powder when mixing.

The problem with my use of paper tape is it hard to get just the right amount of mud under it. Too little and it does not adhere. Too much and I sand into it.

 

[Echd]

As a casual DIY type I learned to embrace fiber tape. Pros may eschew it but for non corner work it does well in my experience and practically speaking is quite easy to do well.

 

[Gotcha6]

As a casual DIY type I learned to embrace fiber tape. Pros may eschew it but for non corner work it does well in my experience and practically speaking is quite easy to do well.

I have never seen mesh used on a corner either. With regards to drywall mud, for smaller jobs the finishers we use will use a quick setting (Durabond) mud for base and bed coats, then apply a skim coat with regular compound. The quick setting compound will cause the paint to flash as they are more porous upon setting so it is not used for the skim, or finish coat. Also, a rookie mistake I've seen (and done) is to over apply mud and then have to sand it back off. With some patience and practice, you will learn to put on just enough mud to make the seam disappear upon final coating.
JMTCW

 

[Echd]

After a few failures I fell into a bad habit of over mudding like you state... I will add that the WEN brand drywall sander is a fine investment, a well made tool, and it will quickly make a room look like a Tony montana booger sugar party just took place in it.

 

[JimD]

My first Festool was a little hand sanding block you can attach a vacuum to. I use it for drywall sanding. I do not do enough drywall to get good at mudding so I need to sand.