View Full Version : Drywall seam cracks in ceiling

05-02-2011, 07:17 PM
Someone please tell me if I am wasting my time or if this is a good solution....

Garage is 42' wide, with rafters 24"OC. I used 5/8 4x12 drywall on the ceiling run the long way, so each 12' piece spans 6 rafters. The long seams have cracks in them. The tape and mud cracked. I used paper tape and the bucket pre-mixed mud.

My proposed solution, which I have already done about 12' of, is to take 2x4 blocks 22" long and go up into the attic space and glue them over the seam laps that are exposed between the rafters. Then remove the cracked tape and mud from the garage side. Once the tape i removed, I get the screw-gun out and run screws down the joint, screwing down the 2x4x22" block. Then retape and paint.

When screwing down the pieces I have done so far, I am seeing the seams move a little, and draw up tight. Once finished with the screws, pushing on the seams shows no movement between the sheets of drywall.

Will this work to keep the cracks from coming back, or am I wasting my time and effort? My thought is that I am tying the seams together into a solid piece and thereby preventing movement between the pieces, which I figure is leading to the cracks.

Thoughts, criticisms, complaints, (even silly jokes...) would all be welcome. I dont want ugly cracks going across the ceiling of my garage!

05-02-2011, 07:32 PM
Sounds like it might work. Did you use ceiling drywall? It is more dense then the stuff for walls and thus less movements and cracks.

05-02-2011, 08:22 PM
Do you maintain the tempature in your garage or does it fluctuate with the weather ?

05-02-2011, 09:11 PM
My 24x30 ft. garage is also dry walled and has some ceiling cracks - I don't thing they can be avoided, unless you put in some load bearing walls (then it becomes a stiff house).
- 30 or 40 feet is a long open span, and high wind can stress the 4 outside walls / and the interior
My ceiling has full 5/8" T&G plywood, on top of the wood-I beams, so mine ceiling dry wall had a tight substructure and it still cracked some.

Beaumont { :>))
1965 Malibu S/S, 1966 Beaumont Custom original paint, 1967 Beaumont Custom, 1967 Beaumont Custom original paint, 1967 Beaumont 396-350HP Sport Deluxe M21-411's - SOLD 1970 Judge

05-02-2011, 09:38 PM
ceiling cracks are like concrete cracks--EVERYBODY GETS THEM SOONER OR LATER :beer:

JUST DO YOUR BEST WORK and enjoy your finished job :thumbup:

05-02-2011, 09:39 PM
First of all,stop useing that premix crap and get some hot mud. I always tape with 210,and finish with 90. Fill the seams with mud BEFORE you tape with paper tape,no mesh. Mesh is for imbedding in repairs,not seams. If you want to skim coat with pail mud,dont use the HD or Lowes stuff,get some real topping from a drywall supply store. I would put a couple 3 1/2" screws in the blocks as well.

05-02-2011, 10:04 PM
Yes,it known as hot mud because it contains plaster of paris that causes it to "set" as opposed to "dry" like the latex base pail mud. Almost no shrinkage either. You can go back over it in 4 - 5 hrs too.

05-02-2011, 10:28 PM
Some good suggestions above. Only question I have is did you paint it with good exterior primer and paint. Dry wall tape and mud doesn't do well when left bare.


05-02-2011, 11:11 PM
Your system will work for sure . I used to work with a home renovator when I went to college and we used to use a similar system all the time to compensate for drywall spanning too large an opening .You don't need to glue the blocks in place . Just screw them into the sheets that butt together .You also might not have to remove all the tape . Just cut out the really bad sections . My $ .02 ...

05-03-2011, 05:04 AM
My drywall guy was explaining to me about the cracks in my garage ceiling. He stated that the ceiling was never painted for one. With moisture the raw compound will attract moisture. When the temps fluctuate and get down below freezing once in a great while, the moisture will expand and cracks will form. Additionally, not enough insulation in the garage attic but we never heat it anyways in the winter. Also along with this, one may experience truss rise on certain portions. This usually happens within the first year and any moisture in the trusses. Heating and cooling will cause thermal expansion and the truss will actually rise causing cracks. With that, we have lived i our house since '93. The house was built in '88. In the winter we still get it for some reason. We have two doors in the house that one will shut fine in the winter and the other will bind in the winter. Summer months....just the opposite on both doors. Go figure!!!

05-03-2011, 05:34 AM
Kevin, my understanding of truss rise is it, is caused by temperature differentials. All of the trusses I have seen use kiln dried lumber.

Had same issue with my garage ceiling with cracking. My garage is heated (to about 45F) and I used 5/8 Fire Code 12' sheets The garage is 26 x 32ft. I re-taped with mesh, cause in my experience the mesh does better with any kind of movement. Also used the "depot Cheapo" USG ready mix. Almost no cracking the last two years. If I thought of the hot mix I might have used it.

05-03-2011, 07:47 AM
I also had the seams pop on my ceiling after I retaped/mudded them. I figured it was going to happen, so I thought about a good fix to lessen it. I ran surface conduit off the center ceiling outlet for the garage door opener, and routed the piping over the seams.

I now have 4 outlets for drop lights and extension cords, and the seams are not that noticable. (and yes, I still need to do something with the floor!)

05-03-2011, 07:51 AM
I always glue drywall backers on the joints.....everywhere...scraps are great for this..

05-03-2011, 08:14 PM
I always glue drywall backers on the joints.....everywhere...scraps are great for this..

^^^ This is the answer. Roofs move as they are loaded with snow, expand, contract, etc. (This would give you hairline cracks that may grow/shrink at different times a year.)

Screwing and - more importantly - gluing backers across the crack with construction adhesive will make the whole surface behave as one continual unit.

05-04-2011, 10:23 AM
What to use as backers, 1x4's?

05-04-2011, 10:38 AM
I used hot mud and paper tape. Mine stays heated. It cracked too. I was a bit bothered at first but I got used to it. Some day when I'm doing a repaint I'll fix it then. I know in some houses when there is a really large expanse of drywall they will sometimes put an expansion joint in. I've only seen it a couple of times but I can't see how drywall would be any different than concrete. It's going to expand and contract.

05-04-2011, 10:48 AM
Hot mud is not always the answer. Pro tapers use 2 kinds of mud, taping and finishing. Taping mud has more binder, or glue, in it. It generally comes in a box, not a bucket. The bucket stuff is generally an "all purpose" mud which, to me, has always seemed like a compromise. When I do buy the bucket stuff, I add glue to the mud for the first embedding coat.

The glue can be anything from carpenter's glue to the thin, milky bonder stuff.

I also concur with several above that drywall in a garage can suffer from weather not seen in a house. So each and every suggestion deserves consideration.

05-04-2011, 07:26 PM
What to use as backers, 1x4's?

Anything that you can glue solidly. Pieces of cheap plywood are probably most cost effective.

05-04-2011, 08:00 PM
I have been using the construction glue because the ceiling is already finished and my arms were not long enough to reach up into the attic and hold the 2x4 while also screwing it in from the underside!:)

I have all of the scraps glued in place...thankfully it was about 50F outside yesterday so the attic was actually quite cool and pleasant! But then again, since I am in east TN, I am just glad I HAVE a roof after the tornados last week.

I have scraped the old tape off two of the seams (42' long each) and screwed it about every 6 inches. I noticed that there was no noticable movement between the drywall sheets near the joists, but between the joists I saw some movement as the screws tightened the 2x4 backer down against the drywall.

As others have also stated, my thinking was to draw the seams tight so the entire ceiling would move and act as one large piece of drywall. Time will tell.

I spent a lot of time making sure my original seams were smooth and as near to perfect as a novice (and perfectionist) could make is killing me to tear out these seams and start over. I had originally thought about putting some backers against these seams when I put the drywall up last year but talked myself out of it.

Thanks for the ideas...I will let everyone know how it turns out...probably take me a couple of weeks to get it all done, remudded-and-taped, and primed.

05-05-2011, 01:28 AM
What was used as drywall tape? I've seen the fiberglass tape crack in the joints. My experience with the old style paper tape has been better.

05-05-2011, 08:59 AM
I used paper-tape and premixed general-purpose low-dust mud.

05-05-2011, 10:14 AM
I've used mesh tape and Durabond on my garage wall joints and they cracked. I think the backer may be the solution to many of these issues (although it can't be done on walls).

05-05-2011, 11:15 AM
The best and final way to address this is to have drywall professional come and put an expansion joint in.

05-05-2011, 12:48 PM
Same issue in my garage. What i did is run a bead of white paintable silicone caulk in the crack used my finger to smooth it out flush, and have never had a problem since (2+yrs). Probably not the "best" approch but you can't tell I fixed it and it flexes with the rest of the drywall.

05-27-2011, 08:00 PM
I finished up repainting the ceiling this afternoon. I put in the backer-studs and screwed them down. It really does look good. It was a fair bit of work to redo the seams...roughly 200 feet all totaled, but I am really glad I did it.

Time will tell if it will crack again, but I think that since it is all tied together along the entire length of each seam, there is no way I can get any relative movement between the sheets of drywall.

05-27-2011, 08:33 PM
First of all,stop useing that premix crap and get some hot mud. I always tape with 210,and finish with 90. Fill the seams with mud BEFORE you tape with paper tape,no mesh. Mesh is for imbedding in repairs,not seams. If you want to skim coat with pail mud,dont use the HD or Lowes stuff,get some real topping from a drywall supply store. I would put a couple 3 1/2" screws in the blocks as well.

I agree with turbomax and would suggest that at least 2 - 3 1/2" screws in each end of the 2X4's from the outside of the truss.
Just my $ .02