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caulking drywall corner joints

drbgwood's picture

I'm putting up a little drywall on a small project I'm working on...  On the corners, I know they are typically taped, but I've installed it so neatly this time, it's tempting to just caulk a few of them instead of tape and mudding.  Some of the corners I'll still tape and mud the old fasion way, but for the most part I've got the qyp board fitted well enough that it looks like a bead of caulk will work just fine and certainly save some time.  Any reason I shouldn't do this?.. the drywall is well secured and I dont expect enough movement to cause a caulked corner joint to fail.

(post #81675, reply #1 of 42)

I don't think I would try that unless it is in your own house.  We don't expect movement but if the house is built of would and you get seasonal changes in humidy, then your going back to do it right later for free.


Have a good day


Cliffy

(post #81675, reply #2 of 42)

I like the concept.  Unfortunatly, one of the faces the caulk would be adhearing to is gypsum powder.  There is nothing that really keeps gypsum adhearing to itself, so trying to bond to it might work for a little while... but I doubt would hold up.


Just my half azzed thoughts.


Rebuilding my home in Cypress, CA


Also a CRX fanatic!


If your hair looks funny, it's because God likes to scratch his nuts.  You nut, you.

YAY!  I love WYSISYG editing!  And Spellcheck!

____________________________________________________

(post #81675, reply #5 of 42)

I might give it a try on just a few of the corners...  all the sheet rock is installed horizontally so tapers arn't an issue, other than the ceiling, and only on the best areas where the rock is so tight and perfect I could almost paint it with doing nothing at all I might caulk.  If it saves a few minutes per coat of mud....


I follow up and visit with my customers yearly, so I'll keep a close eye on it.

(post #81675, reply #6 of 42)

I wouldn't do it.  Even if your customers are friendly, understanding and not very particular, I wouldn't want to be in a position to answer a question from them as to why it cracked by saying "well, I tried just using caulk instead of the typical tape and mud... I thought it would work, but it didn't".  It's just not very professional.  It's one thing to not know and another thing to know but try and take a shortcut.


I don't think you can get enough caulk in the corner (and still keep it square) to allow it to stretch and resist cracking.  It doesn't take very much movement at all to create a hairline crack and our eyes are very good at picking up these imperfections.


A "shortcut" that I might consider would be self-adhesive drywall tape.  That way you can skip the mud bed and just use 2 topcoats.  A corner tool will let you get it done twice as fast as the common technique of spackling one side at a time.  I haven't used self-adhesive tape on corners, but I often repair damaged drywall this way since there's usually much less chance of cracking when the repair is all in one piece of drywall.

(post #81675, reply #3 of 42)

If you have rocked neatly, you have two paper faces in contact. Caulk it. On occasion (only) I have done this. l5 yrs. later it's still good to go.

(post #81675, reply #4 of 42)

As another poster said, (unless you installed the DW with the tapers into the corner) you're gonna be dealing with a thin layer of paper and then exposed, dusty gypsum. Not a good recipe for sticking caulk. Frankly, most of my corners are close enough to caulk, but I wouldn't do it. DW just isn't made for that. The paper surface is just too lose. Any movement in the underlying structure (e.g., wooden studs expanding/contracting with humidity changes) will stress the joint beyond the ability of the DW and caulk to work as you plan. Remember, for caulk to work properly, you need to leave a 1/8" - 1/4" gap to force the caulk into, or there's not enough caulk to allow flexing, expansion or contraction.


If you did put the tapers into the corners, it'll look like carp unless you level out the tapers.


Frankly, if this was a good plan, DW mfgrs would be all over it. There're good reasons they don't even hint at this as an acceptable practice.


Why do you want to do this anyway? Taping inside corners is about the easiest part of taping. Just bed it, let it dry, and then feather the edge of the tape. You don't even need to cover the tape with mud. Two coats usually does it.


The upside is that, if you do decide to caulk, you can always go back and do it right later after the joint fails. ;-)


Mike Hennessy
Pittsburgh, PA

Mike Hennessy
Pittsburgh, PA
Everything fits, until you put glue on it.

(post #81675, reply #36 of 42)

I'm doing another minor drywall job, this time in my own house.  I was thinking back to what you said about how easy it was to tape corners...   Just bed it, feather the edge, and not even cover the tape with compound...  so your saying that the tape will still be visible when it's ready for painting, but after painting it's all good?

(post #81675, reply #37 of 42)

The tape will take paint, much like the paper face of the drywall.

I tend to cover the tape pretty thoroughly, though.

(post #81675, reply #39 of 42)

It sounds like not to the point where if you mud one side, it's difficult to mud the other side without leaving a corner track in the first side while it's still wet... your'e putting your second coat of mud on both sides of the tape at the same time?

(post #81675, reply #40 of 42)

Right. Trying to cover corner tape like you would for a field seam becomes difficult because there is no good easy way (without expensive tooling) to form a straight corner in mud. You can do it with a corner trowel, but it takes a lot of practice to get good at it.


I tried to find the drywall site for you that I had bookmarked, but it's not on this PC, so I'll just try to explain it a bit better.


You want to bed the tape well. I apply a generous coat of mud on the bare corner, both edges. Then, fold the paper tape and apply it to the mud. Make sure your bedding mud is a bit wet -- it sticks to the paper tape better than if it's too dry. Take your 6" knife and run it down each leg of the angle. Apply enough pressure to bed the tape, but not so much as to squeeze out all the mud. Apply enough pressure on the corner of the knife that's riding on the drywall (as opposed to the corner that's riding on the tape) so the squeeze-out and extra mud is feathered out from the tape. But be sure to apply enough pressure on the corner of the knife that's riding on the tape that you don't leave a ridge of mud on the tape. I use a knife that I've ground the corners a bit round, so it doesn't rip/cut the tape in the corner.


You should end up with bedded tape that has little or no mud on it, slightly elevated from the plane of the surrounding drywall. On the next coat, if I have time, I do one leg, let it dry, and then do the other. That's just to avoid issues created when some mud gets away and onto the adjacent leg. Othewise, I just do both legs at the same time, but am more careful not to get mud into the corner. I use 10" knife and skim the leg. Some mud does get on the tape, but hardly any -- just a skim coat. The idea is to merely feather the joint where the tape meets the drywall out into the field, trying to keep mud out of the very corner. If necessary, you can third coat with thin mud to fill in any pinholes or voids left after the second coat. With care, this is often unnecessary.


You end up with a bit of exposed tape in the corner, but that's no big deal. It's firmly bedded and the mud under it makes it plenty strong. You do have to be a bit more careful when you sand the joint so you don't fuzz the tape. But if you're careful with your trowel, only minimal sanding or wet-sponging will be required.


After painting, it's all good.


In teaching My Lovely Assistant how to finish drywall, I told her to think ballet, not boxing, when using the knife. Long, smooth movements, instead of jabbing at the mud like Rocky Balboa. And voids are no big deal -- you don't need to worry much about them when you're running a joint, because they'll be easy to fill in on the next coat(s). Ridges or bumps are not good, since you'll have to sand them out before you can move on, so they are worth avoiding/smoothing out while they are wet.


Mike Hennessy
Pittsburgh, PA

Mike Hennessy
Pittsburgh, PA
Everything fits, until you put glue on it.

(post #81675, reply #7 of 42)

well i have to break from the pack on this one.first i'm not a good finisher and corners are even more fun.


 i do this alot,i get the joint fitting good and run a bead of caulk. i have never had a problem.when you paint  it no one will ever know.


i read this in a magazine once,under tricks of the trade,beendoing it ever since. larry


if a man speaks in the forest,and there's not a woman to hear him,is he still wrong?

the older i get ,

the more people tick me off

(post #81675, reply #8 of 42)

I whimped out today and went ahead and taped everything.  For the first time today, I used the trick with the bucket with two slits cut into it down at the bottom - tape in one, tape out the other, and filled it with dw mud... the poor man's banjo.  I should had been doing it like that a long time ago.  taping went lightning fast, so I started tapeing everything in sight.  The hands get real messy, so you'll want to make friends with a five gallon bucket of water close by at all times, but other than that, it's the way to tape.

(post #81675, reply #9 of 42)

Poor man's banjo? One of those 'why didn't I think of that' moments. Plain, straight-forward excellent idea.

(post #81675, reply #14 of 42)

"...bucket with two slits cut into it down at the bottom - tape in one, tape out the other, and filled it with dw mud..."

How's that again? Is that slots on opposite sides? Please elaborate for me so I can try it.

I do little drywall jobs - repairs, install a pocket door, etc - and taping in corners is awful for me, bubbles, rumples, the works.

BruceT
BruceT

(post #81675, reply #15 of 42)

I saw it in one of those "tips" sections in FHB a while back.  Yep, cut two horizontal slits in oposite sided of a bucket, just big enough for the drywall tape to pass thru one and out the other... the outfeed side may be just a bit looser around the tape so a thin layer of mud will be sticking to the tape as you pull it out.  Set the roll on a dispenser of whatever you can rig up on the feed side.  I just sat the bucket on my work bench and fixed it so it would stay put as I pulled the tape thru.  Water the mud down just a little, you'll probably need to experiment just a little for this, and as I pulled the tape thru with one hand, it help sometimes to jiggle the mud just a little with a stick or tapeing knife with the other to help it adhere to the tape as it was passing thru.  You end up with a peice of pre-mudded paper tape that you just stick to the wall and set with your tapeing knife.  A lot faster and easier than what I had been doing (and even see the full time guys around here doing as well) by mudding the wall and then bedding the tape in it.  Your hands are going to get messy real fast so keep a bucket of water close by for to deal with that minor problem.


As for the second coat of mud in the corners after the tape has dried, one of the other guys on here said that was the easiest type of joint to mud... I wished I knew his secret...  for me, I had generally stuck to the method of building up the second coat on one side, letting it dry and then mudding the other side... which is the slow way.  After a few hundred hours of occasional drywall jobs over the past few years, I'm just now getting to where I can build it up wet on both sides of the corner at the same time for the second coat and have it turn out right.  I tried one of those corner tools in the begining, but gave up on that quickly... and I have never seen a pro using them.  A 6 inch blade works best for me on the inside corners.


 

(post #81675, reply #16 of 42)

my 2c,


In the process of doing both taping and the controversial "caulk" joints in couple areas. Caulked joints in the past (ie. where meeting other finished surface)...15 years later..OK


Inside taped corners...as was mentioned, I always struggled with these till I invested is a wide corner trowel...yep two coats after tape...mud applied liberally with 6" knife to both sides (not neatly, just somewhat evenly right in to the corner & out  5"-6") then smoothed with the corner trowel (sometimes 2 passes) from top down to close to bottom then up from the bottom to where you stopped. Use 6" knife to feather the "ridge" left by the outside edge corner trowel. Very little sanding required!


Tape banjo...tried the bucket thing and it worked well on this job...just make sure you have enough of mud on back of tape or it will bubble on 2nd coat....and start by trowelling mud thru hair, on face, clothes, site radio and over all non-drywall related  tools near by etc!!!!!   


Good Luck


 

(post #81675, reply #17 of 42)

I've never caulked inside corners, but we started soing something similar about a year ago I wished I had tried when I first thought of it -


Often times when remodeling we add a wall, or resheetrock a wall.  It can be a pain to tape the inside corner between the new wall and the existing (already finished) ceiling or wall it abutts, especially out here in the land of textured drywall. 


We mask the edge of the finished wall or ceiling with wide masking paper.  Then hang the new wallboard, leaving 1/16" or so gap in the corner.  We then use L metal with a bead over the edge of the drywall, tape it tight to the masking paper as if it were one side of a conventional inside corner.  We then cut the masking paper with a knife, prime, caulk the joint, and paint the new surface without ever touching the original ceiling or wall we are abutting to.


Probably something most remodelers have been doing their whole careers, but I'm sure glad we tried it.  I have spent I don't know how much time sanding the abbutting surface, removing and retexturing to match original...what a pain in the neck.  This way is faster, cheaper, better.


 


 


I'll eat your peaches, mam.  I LOVE peaches!

(post #81675, reply #19 of 42)

We mask the edge of the finished wall or ceiling with wide masking paper.  Then hang the new wallboard, leaving 1/16" or so gap in the corner.  We then use L metal with a bead over the edge of the drywall, tape it tight to the masking paper as if it were one side of a conventional inside corner. We then cut the masking paper with a knife, prime, caulk the joint, and paint...


What is "L metal with a bead"?  I'm trying to understand your technique, but I can't.  Do you mean tear-away L-bead?

(post #81675, reply #23 of 42)

It's a tape on corner metal. All the big box stores sell them around here, Don. They have a bead, just like a regular nail on outside corner metal. One side of the metal is wider than the other (I guess for 1/2" or 5/8" board, not sure). 


Anyways, what we do is slice the paper off the thin side and slip it over the egde of the new board, which leaves the bead against the masked surface.  Then we more or less flat tape the piece that is laying against the new board.  The bead along the edge gives a nice sharp edge to mud to, just like on a metal outside corner.


Clear as mud, huh?


I'll eat your peaches, mam.  I LOVE peaches!

(post #81675, reply #25 of 42)

I presume that you don't cut away your masking paper until you have done the final mud coat and texture?

BruceT
BruceT

(post #81675, reply #32 of 42)

Right. 

I'll eat your peaches, mam.  I LOVE peaches!

(post #81675, reply #22 of 42)

Jim,


I was introduced to the technique you mentioned when I worked in a university carpenter shop. I spent summers there just adding partitions all over campus, most of which would butt into a finished wall or T-bar ceiling grid. In those days, we only used the metal L's,  but have you seen the tear away L's that Trim-Tex sells for this purpose?


http://www.trim-tex.com/productsindex.htm


Towards the end of my stay there, we started using the tear away beads up agains the T-bar grid to keep the mud off of it.


Check it out, it might save you some masking time.


 

(post #81675, reply #24 of 42)

Yeah!  That would work great!  Haven't seen those before, thanks (now I just hope I can remember them next time I run into that situation).

I'll eat your peaches, mam.  I LOVE peaches!

(post #81675, reply #28 of 42)

yer talking about the "surface applied" bead, right?


 


just lays on top ... and wraps the edge.


around here it's used / sold for plaster.


but I have used it to make for a nice crisp edge on drywall.


usually set it with durobond or easysand.


 


I usually pull it out when I'm going up against an irregular surface that I'd rather not scribe / caulk against.


Jeff


 


Jeff


 


 


    Buck Construction


 Artistry In Carpentry


     Pittsburgh Pa

    Buck Construction

 Artistry In Carpentry

     Pittsburgh Pa

(post #81675, reply #33 of 42)

Yeah, I guess, Jeff.  Sounds like the same thing.  Same principal at least.

I'll eat your peaches, mam.  I LOVE peaches!

(post #81675, reply #38 of 42)

I'd really like to see an illustration of what you are talking about (or if anyone else can supply one).

Rebuilding my home in Cypress, CA


Also a CRX fanatic!


If your hair looks funny, it's because God likes to scratch his nuts.  You nut, you.

YAY!  I love WYSISYG editing!  And Spellcheck!

____________________________________________________

(post #81675, reply #20 of 42)

I am surprised by the number of people who have had success with caulking inside corners.  I would have thought it would fail every time, but guess if everything is stable and moisture levels are consistent, it actually can work.


Also, it would need full-length nailers.  Otherwise, bumping it would open up a crack.


I still don't think it's a good idea even if only because mud and tape is cheap insurance.

(post #81675, reply #21 of 42)

I too am surprised at the claims of long-term stability of caulked corners. I'm also surprised at the amount of resistance to taping and mudding the corners. I think it's one of the easier parts to tape, though certainly slower because of doing one side at a time. But heck, you've got the knife and mud in your hand already, how hard is it to run a corner really...

Steve

(post #81675, reply #34 of 42)

Think in terms of drying time, and a small job. Say you were going to go into someone's house, throw up a small new wall, install a door in it and go. You get your framing and everything else done , and about three in the after noon it's time to think about taping or caulking. I don't do it alot, never on larger jobs, when I'm going to be around anyway. But on one or two day jobs, I've done it and had good results.

Remodeling Contractor just on the other side of the Glass City

Remodeling Contractor just on the other side of the Glass City

(post #81675, reply #35 of 42)

I can see it for that. I also don't have to work against textured walls much. It's just not something I see around here.

If I'm in a real hurry for things to dry, I just use setting compound. But I don't do many small things like that. I'm usually in a place for months.

Steve