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Cracks in seams of new drywall - help - why?

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40K views 21 replies 13 participants last post by  bajafx4  
#1 · (Edited)
I just had drywall installed on the entire main floor of my house that was previously 3/4" T&G knotty pine. The home was built in 1992 and all walls, interior and exterior, are 2x6 16"OC and floor joists for both 1st and 2nd story are 2x12 lumber 16"OC.

My contractor used lightweight "anti-sag" USG 1/2" drywall on walls and ceiling, fiberglass mesh tape (FibaTape brand), and USG Dust Control joint compound for all tape/mud coats (including setting the fiberglass tape).

The sanding of the drywall had been complete for approximately two days (climate controlled house ~68ÂşF) before they primed all the walls and ceilings. After they primed, I noticed hairline cracks in nearly every drywall seam. Quite honestly, you could make out the size of the drywall sheet, be it 4x8, 4x12, etc. based on the perimeter cracks at the seams. After pointing it out to my contractor, he skimmed over the cracks and re-primed the walls and ceiling. Almost as the primer was drying, nearly 50% of the cracks returned and a few more since then which was two days ago.

My first thought in regard to the cause of the cracks was movement, but please see the attached photo of an example of one of the cracks. This is a crack at a butt seam over a 3-ply 12" LVL. I could see cracks happening if the house was moving/settling, but even if the house fell in to a sink hole, I would expect the drywall seams to remian in-tact and crack free over a 12" LVL. I also have cracks at two other seams that are butted up over a 3-ply 2x12 header... again, no movement should be happening here. Additionally, I drywalled two of the rooms in the house several years ago and have no cracks, but the new drywall my contractor installed on the opposite side of the wall that I drywalled has cracks.

I'm not sure how to proceed. I believe the cause of the cracks is a combination of mesh tape and lightweight premixed joint compound. I spoke with my contractor this morning and he said they could go over my seams with "SuperTape," a product I've never heard of and couldn't find any info about online, but is supposedly a plastic joint tape with adhesive paper edges. My opinion of this product is that I'm going to have essentially thicker than butt-joint build up on all my seams with this product, especially because they'll be applying it over the top of already taped and feathered seams and butt joints. Additionally, I think the cracks will probably just return at the edges of the plastic that's bridging the seams instead of where they currently are in the center of the seam.

What do you guys think?

Is there any real alternative to cutting out the original tape and setting mud and/or replacing the drywall all together and then taping/mudding with the proper products?
 

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#3 ·
Most drywallers I know DO NOT use mesh tape for new drywall installs. Paper tape, paper tape, paper tape. Sure, it could be some sort of movement, but, I would think that after, what, 24 years, your house isn't moving too much.
 
#4 ·
Mesh can do that --especially when coated with the soft mud that was used--

I don't use mesh tape--paper ,set in all purpose--then covered with powdered easy sand--

Last coat is the 'light weight' for easy final sanding.

I don't have a solution for you---I think they were not experienced drywall finishers.
 
#18 ·
I think they were not experienced drywall finishers.
No pro sheetrocker I've seen in 40 plus years of doing this stuff would have used webbed tape
I have to disagree with you guys a little - unfortunately they well might have been experienced drywallers, and I see a lot of guys doing this. They have experience - they learned one way to do it (the wrong way) and therefore that's the way they've always done it. They either get away with it (get lucky and it works fine, or the customer doesn't notice in time or doesn't care, or else they weasel out of fixing it or paying for it.) I've seen lots of "pros" make bush mistakes.

To answer the OP and add another voice - mudding over the cracks is pointless and waste of time. The fact that the contractor was willing to even try this proves he's incompetent. If he knew what he was doing but just cutting corners, he'd man up and fix it now. He should know you can't fix a crack with more mud.

IMO you don't need to take the drywall down. But all joints must be ripped out. Mesh tape and drying compound don't go together, including the regular all purpose, let alone the lightweight stuff. You need to get your money back. I would not even bother trying to get him to do it right. If you have to force it down his throat, then he isn't bought in, and you'll get bad results in some other form. Hopefully you haven't even paid him yet, but if so get your money back.

Mesh tape can be used with setting compound, but what's the point? Anyone who's going to mess with setting compound is going to know how to embed with standard paper or even FibaFuse.
 
#5 ·
I have been using mesh tape since it came out. Use the ultra thin since it came out. I have not had any issues with it, HOWEVER, I always use Easysand for the first and second coat. Then I do use the Dust Control for the third coat. Dust control is much too soft for setting tape, especially the mesh. Nothing wrong with mesh but it has to be done right.
Mike Hawkins:smile:
 
#7 ·
Make him come back, about everything he did was wrong. The lightweight weight drywall is absolute junk. The problems you are having is just one of the many problems that's becoming known to this material. In the area where I live there are 3 different drywall companies and all 3 have stopped selling the lightweight because of the problems installers were having.

Mesh tape should only be used with setting mud not drying mud. It even says so on the roll. And dust control is drying mud. Multi purpose mud is the least that should be used to set real tape (paper). That dust control should only be used for the final coat. It doesn't have enough glue in it. The glue is what gives mud it's strength, but it makes it harder to sand. That is why topping which is very easy to sand can only be used for final coat. For anything else it will crack.

The drywall is not the best but since it's up I would just leave it. All the tape needs to be removed or the cracking will probably continue into the future. Tell him to just add more mud on top will not fix the problem.
 
#10 ·
Make him come back, about everything he did was wrong. The lightweight weight drywall is absolute junk. The problems you are having is just one of the many problems that's becoming known to this material. In the area where I live there are 3 different drywall companies and all 3 have stopped selling the lightweight because of the problems installers were having.

Hey TS,
I've been using the lightweight drywall since it came out about 4 years ago and haven't had any issues with it. I find it cuts the same, snaps clean, and screws the same. The only difference I notice is in the weight. I can carry double sheets where before I couldn't. Not sure what brand we're getting up here in Ohio, maybe it's something different than you guys are getting in Florida.
Mike Hawkins:smile:
 
#8 ·
Baja, The advice being given is unfortunately what may have happened, wrong materials. If this is the case then the problem now comes down to, will the contractor fix it properly, which may be expensive and he may seek a cheaper way out. Here's where the certificate of insurance comes in and you should have that in hand. With the list of his insurance coverage you can get them involved to see what they recommend for a solution.

If he has insurance coverage, that takes the bite out of the cost issue as it will be the insurance company paying. His choice will be to either absorb the cost to keep his insurance co out of the loop, or let them pay.

Removing ALL of the tape, and not just where you can currently see cracking, is a major job and a big delay in your project. And, the results will be less than the quality you were expecting. Removing all of the drywall and starting over would be my expectation or you will be obsessed with watching every seam and nail as long as you live there.

Good luck
Bud
 
#9 ·
I think the term Easy Sand is being confused here.

Easy Sand is a setting mud it comes in a white bag and mixes with water and has a setting time on the bag such as 90 minute, 45 minute, or 20 minute. This is the time it takes to set (not to dry). This is a very strong product and can be used with mesh tape. The term Easy Sand means it's easier to sand than the Dura Bond in the brown bag that is almost unsandable. But in truth the Easy Sand is not really easy to sand, just easier than the brown bag. So first and possibly second coat is all it should be used on. Then it should be finished with a topping or drying joint compound.

Joint compound comes in several different mixes. The most common of these (because these are what the box stores carry)

Multi purpose This comes in a bucket with a bright dark green lid. And as the name implies can be used for everything from setting the tape (paper) to the finish coat. To use for the finish coat it has the most glue in it so that makes it harder to sand and get a really smooth finish. But it can be accomplished. Trim Tex makes a product called Mud Max which is basically a glue that when added makes this as strong as the setting mud.

Lightweight #3 This is in a bucket with a bright dark blue lid. This product has less glue than the Multi purpose which makes it softer and easier to sand, but more prone to cracking. And can be used for anything except to set the tape. I worked at one time for a guy that used it for all coats because it was easier to use. But we got a lot of callbacks for cracks especially in corners.

Ultra light weight this comes in a bucket with a light green lid. This mud contains very little glue so dries soft and easy to sand this makes it good for final coat and skim coating for walls, but not good at all for taping.

Topping this is in a bucket with a light blue lid and it says topping on the bucket. This product is not available in all areas. Where I live you can't find it and have to order it. When I asked why they said too many were using it as multi purpose and since it contains no glue it would crack so much and they would try to blame the product so the suppliers stopped carrying it. As the name implies it is only used for the final coat and is very easy to sand.

The dust control mentioned is a product I have worked with a few times and personally didn't care for. By duct control when you sand it the dust is supposed to fall straight down and not become as airborne. This does work to some degree. But I found the finish qualities not to be to my liking. As a finish mud I found it to be harder to work with to get the finish I wanted.

Hope this helps.
 
#17 ·
The term Easy Sand means it's easier to sand than the Dura Bond in the brown bag that is almost unsandable. But in truth the Easy Sand is not really easy to sand, just easier than the brown bag. So first and possibly second coat is all it should be used on. Then it should be finished with a topping or drying joint compound.
Which raises a new issue - when you have 2 different compounds on your wall and your sandpaper contacts both of them, it's going to sand the softer one faster. Meaning, you can't get really flat joints using both compounds unless you can guarantee your sandpaper only contacts the softer material of the third coat, and that rarely happens.

This is not always a problem, but it can be.
 
#13 ·
I'm following along and I agree that the products have and are being used. But why the cracking? I'm retired but strangely, I like drywall and don't want to run into this same issue.

Good thread and thanks,
Bud
 
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#15 ·
Thanks for all the replies guys.

They ground out all the mesh tape and mud at the seams with a carbide/diamond type sanding attachment for an oscillating tool (similar to the one below) and redid all the seams with hot mud and paper tape. They're going to prime the walls tomorrow, so we'll see what happens.

Image


Thanks again for the help.
 
#20 ·
Thanks for all the replies guys.

They ground out all the mesh tape and mud at the seams with a carbide/diamond type sanding attachment for an oscillating tool (similar to the one below) and redid all the seams with hot mud and paper tape. They're going to prime the walls tomorrow, so we'll see what happens.

Image


Thanks again for the help.
Just curious, did they damage the paper?
 
#19 ·
I think this thread sums up exactly what just happened to my living room ceiling install. I admit I am an "inexperienced" drywaller, but I like to tackle these projects on my own. Unfortunately for me, I didn't do enough research on the topic before tackling this project (totally my fault). I installed 1/2" drywall on my living room ceiling and finished the joints with mesh tape and bedded with the same exact "dust control" mud you used. Same exact results with it as you too. Painted on primer this past Saturday and on Sunday noticed every seam with hairline cracks. Yesterday was spent removing and cleaning up all of my joints and re-taping with mesh and "hot" mud (Durabond brown bag). Oh what fun....