Sheetrock gone bad….what did I do????
Alright, I posted a week or so ago about taping the sheetrock in my garage. The garage is 24 x 28, r-25 ceilings r-13 walls all covered in 6 mil poly. I hung 12′ sheets on the ceiling (5/8) and 12′ sheets (1/2) on the walls.
I used a mesh style tape that had adhesive on the back. I was told to simply stick it onto the joints then mud over it. I gave everything two coats of mud, on separate days and after the first coat was dry. The garage temp did vary anywhere from 35 degrees to 80 degrees but I made sure it didn’t go below freezing. I’m simply heating with a torpedo style propane heater. There was A LOT of moisture in the air, on the windows, and on the floor.
I was sanding tonight and noticed that almost all of the joints had hairline cracks in them. Then, upon further inspection, I noticed some cracks were actually a 3/4″ wide piece of mud that was loose. As I would sand, the sheet would flex in-between the bottom chord of the truss and this loose piece of mud very visable. One piece roughly 3/4″ wide and 12″ long fell out exposing the tape and bare drywall behind it. The mud joints are at most 1/8″ thick in the middle after two coats.
What did I do wrong????? How do I fix it now???
upnorthframer
“If you think education is expensive, try ignorance!!!”
Replies
What did you bed that tape with?
A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
What kind of mud did you use? (all-purpose green lid, lightweight blue lid? medium weight purple lid? setting?)
That propane heater is putting out a lot of moisture. Could have caused movement and swelling that led to the cracks and interfered with the bond. You might have needed to press harder on the first coat to get it to squeeze through the mesh to make good contact with the board. Or you may have been pressing too hard on the second coat, flexing the joint and breaking the bond, when it might not have been fully set.
I'm no drywall pro, but I get very consistent results with the following method:
I only use paper tape, as I found the FG mesh telegraphs movement and cracks much more easily. I do a first fill of the joints with setting compound just to fill the deep cracks. Then when that sets. I bed the paper tape. I only use green-top mud for bedding as it's harder and seems to stick far better. I let the bedded tape dry completely before puttting any topcoat on. I used to top-coat with blue or purple, but have since gone to using green for everything, because it's harder. But harder to sand too. But once you get a feel for the knives, the sanding gets pretty minimal anyway.
Steve
I'm not absolutely sure if this was the reason for your problem, but........ mesh tape is designed to used ONLY with 'hot mud', setting type compound.
Also, your temperature swings seem a bit extreme.
But, hey, whadda I know? I'm not a drywaller.
Edited 3/19/2008 10:54 pm by kenhill3
There is an article in the just-out JLC on using setting compound. Mentions that mesh tape works better with setting compound, but doesn't seem to go so far as to say only with setting compound. I avoid the stuff (mesh), because I always seem to get hairline cracks in it.Steve
Edited 3/19/2008 10:59 pm by mmoogie
I'm just guessing here. Not actually seeing the job it's hard to tell. Cracks on the second coat of mud tell me the first coat either wasn't completely dry or the mud is two thick. Which doesn't seem to be the case with the latter. If the cement floor is new it would be pretty difficult to get the room warm enough to have mud dry effectively. The new concrete gives off a tremendous amount of moisture.
How dry was your lumber? Can't see it shrinking that quickly thou. Ceiling strapped well? 12" OC is the norm when using 5/8". Shouldn't put screws around the permitter of the ceiling either. Leave 12" all around the ceiling to allow for truss lift without cracking the top corners.
My money is on too much moisture. You should maintain a constant temp. Nothing will dry in a reasonable time frame with such fluctuations.
Good luck
Gary
I used Lafarge quick coat. It said on the box it was meant to be used as a first and second coat application.
I have no other means of heating the garage. Is that amount of moisture the cause of it not setting up fast enough? I was sanding it tonight, got almost 2/3 of it finished. None of it was sticky so I thought it was dry enough.
How do I fix this problem? Could i pick out all of the chucks of loose/cracked mud (which are right down the middle of each joint) the place another layer of the mesh tape, which would span over ther open void, then fill again with another coat of mud? Would this hold up? I'm at a loss as what to do now??? I just want it to look presentable. Any help would be appreciated!!!!!
upnorthframer
"If you think education is expensive, try ignorance!!!"
My guess is too much moisture and maybe too much heat at the ceiling - baked the compound instead of drying.
No, don't add more mesh tape.
I always bed my tape, mesh or paper, in Durabond 90, second coat with Easy Sand 90 and top coat with green top compound.
I would recommend filling those voids with Durabond 90. It's much harder than premixed compound and sets by hydration rather than by dehydration.
Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
Some people will disagree, but I was taught mesh tape only with hot mud and only when you are in a hurry. Paper tape is always prefered.
As a fix I would cut out loose areas and prefill with hot mud. Might consider cutting out cracks by runing a rock knife on them and prefilling if needed, then tape over with paper tape w/ all purpose. Then two more coats.
Another option if the mud is still pretty fresh, cut in and find the mesh tape and pull it off the wall. That should leave a nice 2" recess to bed the paper tape into
I am not familiar with freezing temps out here. When we want our mud to dry we are more concerned about air circulation than heat. I believe propane heaters can introduce more moisture into the air. We prefer just fans.
20 years in commercial/ residential drywall.
Mike
Trust in God, but row away from the rocks.
Another option if the mud is still pretty fresh, cut in and find the mesh tape and pull it off the wall. That should leave a nice 2" recess to bed the paper tape into
That is exactly what I did when I had the same thing occure in my shop.
Where I retaped with paper and setting compound- no more cracks. Where there is still mesh tape, cracks are still showing up. They will get fixed someday.
I do the same... Bedding coat is Durabond, then depending on how much of a hurry I'm in bucket or Easy Sand compound.
I just had to redo the DW work my brother had done about 9 years ago in his kitchen. He used mesh tape and bucket compound (probably a lightweight compound)... EVERY joint was cracked. Ceiling, walls, corners... And no, structural movement was not an issue, and most of the work was done over old (i.e. dry) studs. Now I still have two bathrooms and part of a bedroom to redo, same problem. What a pain!!
As far as I'm concerned, from what I've seen, fiberglass tape and bucket compound just don't mix. And personally, I'll never use fiberglass tape again (stopped using it about 8 yrs ago).
That light weight compound should not be used for tapeing.
Made that mistake once because I had a piece of a bucket from another job. Even with paper tape, cracks appear about two months later.
This is not the first time this topic has come up for discussion. I'm thinking that it first came up about 5-6 years ago, and has recurred on a fairly regular bases.
Makes me think that maybe something changed in the maufacturing of joint compound. I have been doing drywall work for nearly 35 years, and never had this problem untill the last 5 or 6 years. I have done everything from beginning as a DIY to runnin with the big dogs, i.e. professional finish crews on commercial work.
Something has change, me thinks!
Yup, I've been reluctant to go near lightweight stuff. I tend to stick with the regular (green cap) compound and Durabond.
Here's a question I think the OP asked, and I've been wondering... what really is the best way to fix the problem?
In my case, the ceiling had to be torn out for another reason, so I only had to redo the wall joints, (and remember this is a kitchen, so the majority of the joints were covered by cabinets). For the exposed cracked joints, I took a carbide scraper, knocked the paint and thick JC off (carefully, trying not to gouge the DW), then sanded back down to the tape... got rid of the culprit mesh tape, and pretended I was starting from scratch. One area I had problems with the paper being damaged, had to hit with spray-bomb Kilz to seal the DW from moisture before retaping (the paper was bubbling under the paper tape... made a nice mess). Anyway, this process is tedious at best, but comes out looking great. And I would NOT recommend it to the OP.
I notice "The Drywall Man" Ferguson has mentioned in one of his articles using mesh tape and bucket mud for fixing cracked joints. My thought is, "What, so I can redo this a 3rd time???". Seems to me this is one of those cases of "Do it right the first time, or spend 4x the original time redoing it."
Those propane heaters are a terrible thing on residential jobs. They introduce a huge amount of moisture into the building. Get an electric heater and get your electrician to set up a 240V outlet for it. Use fans.
I agree with whoever said to pull out the mesh wherever possible and start over with paper. I never see pro finishers using mesh, mostly they use bazookas with paper tape, but even when doing a small area they use paper.
I'm with David... I have never seen a pro drywall guy use mesh tape for anything...
I have never seen a pro drywall guy use mesh tape for anything...
Sure, it doesn't work in their banjo boxes and, anyway, it's for DIYers so it's beneath their dignity.
I've used mesh tape for years on tapered joints and paper tape in corners and possibly in butt joints (though I try to avoid any butt joints - there were none on the last house I did).
I always bed with Durabond, second coat with Easy Sand, and finish with the bucket. Never a crack.
Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
Maybe it's a cost thing too?
I agree with the others about using paper vs. mesh, but...
its a garage. Don't get so carried away with it. Once you get it stuffed with everything, you won't notice the cracks.
OK, you'll notice.
But no one else will.
It's not the tape that did you in, it's the mud and environmental conditions.
Contrary to the majority opinion in this thread, I have stopped using paper completely due to endless bubble wars. (Once had a pro drywaller tell me paper was used because it worked nicely in the banjo where mesh would not.) Haven't had any cracking issues, but don't do 1000's of feet of DW either, so YMMV.
I use mesh in the tapered and butt joints, and StraitFlex in/on the corners (glue it in with DW Spray adhesive).
Durabond 90 is a great recommendation for setting whatever tape you use, but is not always required. I use it in spots I think will get bumped or subjected to lots of vibration. Keep in mind with setting type mud (hot) like Durabond 90, you're essentially using plaster. Sanding it later is not really an option and the 90 stands for the setting time. Move fast.
3 coats, not 2 is the norm. For a rookie DIY, 4 coats may be needed.
I agree with the advice to not sweat the details in a garage. It's a great place to perfect your technique though.
I found this out the hard way myself but tape does not stick well unless joints are prefilled (no matter the size of the gap) with durabond. The bond part of that word is what most people including myself fail to realize, this is a very important step in a quality finish.
Jeremey Nichols (remodeler NW Ohio)
I told you bucket mud wouldn't work....
Edited 3/20/2008 7:02 pm ET by sledgehammer
Edited 3/20/2008 7:03 pm ET by sledgehammer
Yes you did, but his question at the time was about the temperature. It sounds like the failure was related to too much humidity and the wrong compound.
I don't have any experience with taping/mudding in very low temperatures, but I certainly wouldn't even think about it below freezing. Once dry, I would expect any kind of compound to stand up to the cold.
Can you expound on why you thought it wouldn't work?
Expound on why it wouldn't work????
Because I used bucket mud in a garage... and it did exactly what he describes.
Called USG they told me the correct materials to use.... Which I do now and never have a problem. Just trying to help a brother out.
Edited 3/21/2008 7:04 pm ET by sledgehammer
You have to use setting compound with mesh not the bucket stuff. Bucket is okay for topping but you need the setting compound to bed it in.
As far as a fix, you're not supposed to cover bucket with setting so you may need to pull back the tape and start over.
ask Myron
IMHO the FG mesh tape is the wrong tape for that application.
When drywalling ventilating (air movement) is more important than actual heat. Propane heaters are bad for drywalling, they also yellow the walls later on.
Next time use electric heaters with a big fan (dia) and slow rpm, open windows a little bit.