# repair of drywall hairline cracks



## racebum (Mar 8, 2010)

re hung the entire ceiling in my house this year due to moisture, well more like heavy rain and a tarp blowing up in the middle of a rainstorm but that counts as moisture right? :whistling2:

anyway there are a few hairline cracks that came out after the temperature dropped, insulation was blown in and general settling took place. i should also note the 3 rooms i finished in paper tape are perfect but the others done in glass are where the cracks are. yes it was done in setting compound and yes it was dried out before paint. 

i was considering pushing caulk, something really sticky and flexible like that $7 tube 1hr stuff from GE in the cracks then doing touch up texture and repainting.

any better ideas?


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## Polywanna (Oct 22, 2010)

Can you post a picture please?


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## bjbatlanta (Jul 16, 2008)

Even with setting type compound, mesh tape is more prone to cracking. Moisture, drying lumber, etc. causes "movement" that will make cracks. I only recommend mesh for small repairs where using setting compound saves time, and repairs can be done in a few hours as opposed to days. Your idea is a temporary fix at best....


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## epson (Jul 28, 2010)

Just do it the right way: :whistling2:

1) Apply drywall mud to the hairline crack with a 6'' taping knife by smoothing the mud into the crack filling the crack entirely.

2) Cut a strip of mesh drywall tape to cover the crack and press it into the crack while the drywall mud is still wet. Smooth out the mesh tape to eliminate any wrinkles.

3) Apply a top coat of fresh drywall mud over the mesh tape by using gentle pressure to push the mud into the small holes of the mesh tape.

4) Now use a 12'' taping trowel, and gently smooth the mud along the tape. Using this wider taping knife pushes the edge of the mud outwards to reduce the appearance of a bulge over the tape.

5) Remove any excess, and allow the wall to dry completely.

6) Repeat the application of drywall mud with the 12'' trowel, adding a little more to the taped cracks and smoothing them out as flat as possible because drywall mud shrinks slightly as it dries. Allow the wall to dry completely.

7) Sand the wall with a drywall sanding pad after your mud is completely dry and run your hand over the repaired seam to check for rough spots.

8) Once all your sanding is done, apply a good oil base primer.


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## bjbatlanta (Jul 16, 2008)

If mesh tape caused the original problem, I don't think I'd use it for the repair. Use paper tape....


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## racebum (Mar 8, 2010)

bjbatlanta said:


> If mesh tape caused the original problem, I don't think I'd use it for the repair. Use paper tape....


exactly, the post above yours is a great way to spend 40hrs to accomplish the same thing i already have. the only issue is that i have a nice flat finish i spent quite awhile on and texture everywhere. to sand down and retape will take a lot of time, make a mess and i hope won't be needed. so far this caulk idea is holding fine and blended perfect. the cracks were so small...bout the same size as the cardboard used in cereal boxes to the edge of a piece of paper that i didn't want to retape the entire job doing so would turn the ceiling into a mass of butt joints and require going out at least 8-12" on each side of the tape line to blend it.


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## bjbatlanta (Jul 16, 2008)

Understood. Just saying the caulk will eventually crack again. I've done this too for one small, recurring crack in my kitchen ceiling (maybe 12" long) and have to re-do it every couple of years. Re-taped it the first time and it came back anyway. It's just not a permanent solution....


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## racebum (Mar 8, 2010)

just had a thought last night when i was staring at the ceiling waiting for water to boil. when i finished the kitchen the lines were perfectly flat but not appear to have shrank up just a touch. the kitchen and living room were where i used a watered down topping compound for the top coat which coincidently are where the hairline cracks are. another room i also glass taped is fine but that room used straight out of the box for the top coat. all rooms were set in hot mud. anyway, since i only caulked one line so far i started wondering if a combination of new drywall settling and shrinking top coat could be the issue. if it is would crack filling with hot mud possibly be a better plan for the rest? the cracks don't appear to be very deep and may just be in that top mud.


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## 595287 (Jan 4, 2010)

You might be on to something racebum. What about sanding what appear to be surface cracks, wiping dust, and then mudding with setting type compound?


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## lrobertstoner (Mar 18, 2011)

bjbatlanta said:


> Even with setting type compound, mesh tape is more prone to cracking. Moisture, drying lumber, etc. causes "movement" that will make cracks. I only recommend mesh for small repairs where using setting compound saves time, and repairs can be done in a few hours as opposed to days. Your idea is a temporary fix at best....


 i so agree with you on mesh and its usage i wonder if maybe he froze the mud and it finally thawed on him just a thought:thumbsup:


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## lrobertstoner (Mar 18, 2011)

i just say this about the hot coat and regular mud
i prefer the regular used it all my life and never had problems with it
the hot coat i always had some type of problem lap mark not sanding out cracks in corner bead and this sounds a lot like that
take your 5" knife and scar the cracks making a valley 
aply your topping mud that you textured with into the scars pulling tight
repeat until scar is coverd and hidden 
if this isnt like a road map you can use your hand to blend in texture
if so sand smooth and retexture
note if this was frozen eventually the tape will bust out or bubble out 
and here is another note for all dyi we use the usg green lid for tapeing because it has more glue in it then any other joint compound


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