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-   -   Mesh Tape (http://www.diychatroom.com/f101/mesh-tape-135568/)

dustinfox 03-01-2012 11:46 AM

Mesh Tape
 
I just finished taping the drywall in a 12X25 room over our garage. For decades I have always used paper tape for my drywall projects and never had a problem. But on this project I thought it would save time to use mesh tape. I just finished sanding and now I am getting hairline cracks on many of the seams. After doing more research, I am learning that mesh tape will cause problems if not done with special mud or adhesive. I am also hearing that the only solution is to dig out the seams and replace the mesh with paper. :cry:

Does anyone have another repair method? If not, what is the easiest way to remove the old tape? I chiseled out one test joint and it was slow going. The mesh is pretty well embedded into the joint compound and comes out in strands.

Any help would be greatly appreciated.

Thanks

princelake 03-01-2012 12:18 PM

ive never had a problem with mesh tape ever. i use it for all the butts and flats then paper for the corners. i've used mesh in the corner but i cant seems to get a good square corner. if you are having major cracking along the joints there could be a problem with how the drywall was screwed on and the condition of the joists. the only way to fix it really would be running your paper tape over what you have now and skim it out which definitley suckkks

dustinfox 03-01-2012 01:04 PM

Quote:

Originally Posted by princelake (Post 867485)
ive never had a problem with mesh tape ever. i use it for all the butts and flats then paper for the corners. i've used mesh in the corner but i cant seems to get a good square corner. if you are having major cracking along the joints there could be a problem with how the drywall was screwed on and the condition of the joists. the only way to fix it really would be running your paper tape over what you have now and skim it out which definitley suckkks

Ya that sucks but it would be better than chiseling out the mesh and replacing it with paper. I just want to be sure that whatever I do it will hold and not crack again in a few months.

AtlanticWBConst. 03-01-2012 02:34 PM

Mesh tape should only be used with "Hot Mud" (Rapid-Setting bagged-mix) and NOT with ready-mix in buckets.

Read the discussion here: http://www.diychatroom.com/f101/diy-130966/#post831124

The only correction is to attempt to remove and re-tape the seams and to do it properly with the correct mix and tape.

user1007 03-01-2012 03:56 PM

Quote:

Originally Posted by AtlanticWBConst. (Post 867549)
Mesh tape should only be used with "Hot Mud" (Rapid-Setting bagged-mix) and NOT with ready-mix in buckets.

Read the discussion here: http://www.diychatroom.com/f101/diy-130966/#post831124

The only correction is to attempt to remove and re-tape the seams and to do it properly with the correct mix and tape.

:thumbsup:Or if the fissures are not extreme, see if you can mix some hot mud and skim coat your way out of this. Assuming the mesh tape did not fold in on you and you have nothing to repair.

I know drywallers that swear by mesh tape for new joints. Never allowed on my jobs for customary joints. There is a reason mud and paper tape has lasted for decades. It works. Plastic net stuff does not but for the intended purpose of crack repairs.

By the way, my hands were slapped talking in lingo that DIYers might not get. Let me explain hot mud.

Hot mud is sold according to its setting time. You can buy it, for example, in setting times from 5 minutes to 120 minutes in sacks or boxes with plastic liner. Once it senses moisture, hot mud powder starts to cure. It is nice because you can watch this happening, but with 5 minute you do not have time to watch. With the 20-45 minute stuff, for a DIYer, you can feel the material harden in say a nice drywall pan. When it is the consistency you want, grab a glob with a nice wide drywall knife and spread it on like butter.

You mix hot mud powder with water. If you goof and it does not feel right? Toss the mix and mix a new batch. The sack or box of stuff will cost you chimp change.

dustinfox 03-01-2012 04:21 PM

Quote:

Originally Posted by sdsester (Post 867601)
:thumbsup:Or if the fissures are not extreme, see if you can mix some hot mud and skim coat your way out of this. Assuming the mesh tape did not fold in on you and you have nothing to repair.

Thanks... Would it make sense to sand the joint down a bit and embed another strip of mesh under the hot mud?

user1007 03-01-2012 06:48 PM

Quote:

Originally Posted by dustinfox (Post 867623)
Thanks... Would it make sense to sand the joint down a bit and embed another strip of mesh under the hot mud?

I cannot comment without seeing what you have.]
If the tape is doing it's job best it can, you should not put more tape of any kind over it.

princelake 03-01-2012 09:26 PM

i've never heard the term "hot mud" until i came on here. the only brand around here is sheetrook so everyone in this area just calls it sheetrock 20,45,90.

Gary in WA 03-01-2012 10:49 PM

Atlantic, did you see this on tape strength?:
"In the case of paper tape, approximately 30 lb./lin. in. of tensile force (pulling apart) is required to break the
tape with no measurable movement or elongation (no stretching). On the other hand, glass-fiber tape elongates
(stretches like a rubber band) 0.03" before reaching maximum or breaking load of 70 lb./lin. in.
Research investigation has shown that hairline cracks or nail pops are visible at 0.01" of movement with
veneer plaster system joints treated with glass-fiber tape. Actual load at that amount of movement is only
20 lb./lin. in. or about 30% less than the breaking load of paper tape (with no movement). As such, paper tape
provides greater joint strength and is recommended where greater movement and shrinkage is anticipated.
The performance of glass-fiber tape is somewhat improved if the tape is prestressed or stretched slightly during
its application and imbedment with the veneer plaster. The prestressing is accomplished with the presetting
because as the veneer plaster sets, it expands and furnishes the movement necessary to stretch or prestress
the tape, thus increasing its immediate resistance to load (tensile forces). The amount of expansion provided by
the plaster is dependent on the rate at which the plaster sets. With rapid-drying conditions (see graph), the
plaster expansion will be significantly reduced resulting in no tension (prestressing) in the glass-fiber tape,
thus reducing its ability to control cracking.

Paper Tape Application Techniques The Sheetrock joint tape and Durabond or Easy Sand joint compound method is unaffected by rapid- drying conditions and achieves maximum joint strength (about 30 lb.) when dried. The setting-type compound is recommended, because once it is set, it remains stable, even when troweling the wet coat of veneer plaster
over it. If a drying type of joint compound were used, it would be rewetted by the plaster application causing
movement of the tape resulting in distortion of the finish surface and possible loss of joint strength."

Highlighting mine. From: http://www.usg.com/rc/technical-arti...ems-en-PM5.pdf

And, mesh for flats: http://www.usg.com/rc/data-submittal...ata-MH1178.pdf

Gary

bjbatlanta 03-02-2012 04:44 PM

Most if not all manufacturers of "mesh" tape specify that "at least' the first coat of compound is a "setting" type. Another possibility, did you overlap insulation over the studs rather than "tuck" and staple inside the stud bay?? I've seen that cause the problem you're talking about, especially when not using a "setting" compound. Happened to a guy who works for me when he did a job for a friend of his. I suggested he go back and sand down as much as he could (without actually sanding through the mesh) and putting a coat of DuraBond in the brown bag on, then skimming. It did the trick according to him. You may have to find a drywall supply yard to get it.

user1007 03-02-2012 09:53 PM

Quote:

Originally Posted by princelake (Post 867866)
i've never heard the term "hot mud" until i came on here. the only brand around here is sheetrook so everyone in this area just calls it sheetrock 20,45,90.

Vocabulary does get a little strange. "Setting type" is another term for it all that gets used. I used to spit forth 5 minute durabond and people knew what I meant.


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