Construction/Drywall Guys Question

jsnake

I had a professional mud, tape, and texture my sub basement. It looks great and no shortcuts were taken. After a few days of drying I noticed hairline crack in every corner. Every single corner in the room. He came back and sanded the corners which seemed to fix it for the moment. A few days later they were back. So he tells me to prime it and see what happens. I prime the room and at first it seems to have done the trick. A day or two after drying no cracks. But after a few more days hairline cracks are back in every corner and now I have one in the ceiling and it isn't even where a seam was.

He told me he will be back but he is at a loss because in his 18 years of doing this he has never had this happen. Does anyone have any ideas. One thing is it is very cold in my sub basement. I touched up my priming and hit the corners again. It seemed to help again but now a few days later they are all back again. This time I ran a heater down there but it didn't seem to help. Would like to hear your ideas for what might be causing this and what the fix might be. Thanks

bearb

Not sure what is meant by the 'sub-basement', but perhaps it is what we call a crawlspace? Also, wIthout pics it is certainly harder, but the hairlines cracks could be the result of a few things...improper pre-filling, floating corners, or use of improper mud, based upon his speed:

-the hairline crasks often indicate the use of 'dry' mud upon application....ie mixed durarock 45 and was still using it 50 minutes later..yes it makes a difference, as it has started to set;
-the pre-filling stage (before tape) is also critical, esp in corners so that the mud isnt drawn into the crack excessively...again, this stage CANNOT be rushed, especially if the corners have not been fully locked
-also the number of mud coats (MIN. 3 coats) AND adequate drying time between (use of heater to speed up process will guarantee harilines) as it cures @ uneven rates;
use of paper tape vs fibreglass (esp. important due to the 'basement' location...not meaning to insult, but sadly i have seen 'professional' jobs where no tape was used @ all)....was he a professional carpenter or drywaller?...sadly, no drywall skills are taught in carpentry school;
-Could also be the temp difference between inside and outside of drywall, ie vapour and moisture barrier, isulation, etc.

Solutions? Figure out he cause, or it will continue to happen. If you think it is the improper setting/curing of the mud..then you must scrape it out...do it more slowly, then widen the mud job
Another option, not as recommended is using a HIGH quality paintable latex caulk applied with a scrapper to 'push' the caulk into the crack. Depending upon the paint finish, this might be visible to YOU, as you know it is there...but not likely to any others, even upon close inspection.

Anyway, pics would be best, along with the details of the wall construction, temps in sub-basement, but that gives you some ideas to start. It really takes the wind out of your sails when stuff like this happens...so stay strong Jake. Hope the expanded family is doing well.

jsnake

Sub basement is my lower basement. We have two basements. This one is completely underground.

He used paper tape in all corners and I have no idea what kind of mud. He was going to use fast drying stuff but went with something else instead. Said it would be better that way. It had plenty of dry time between coats and I know he did three. He is a union drywaller and that is all he does -drywall, mud, tape. He did it over a 7 day period so it was not rushed.

The temps down there were probably in the 50's and much colder from the rest of the house.

He initially though it was because when he textured the mud got thick in the corners. We initially did not try to scrap the corners out. He used a sponge to sand and it looked like it fixed it but they cam back. Like I said he says he has neevr had this happen on any job.

Primed and they disappeared only to come back. Primed again and same result. This time I used a space heater and they came back in certain areas but not all. A few areas seem ok now but a large majority have come back.

I am not against using a caulk. I will be using a nice quality eggshell paint and I am sure it will cover well. These cracks are tiny and most people would probably not see them but I am OCD perfectionist. I will try to take a pic and post it after he looks at it again.

Thanks

camgfs

I used to be a drywall guy for quite a few years. This sounds like a temperature problem right from the start. We did a lot of houses in the winter (and damn it gets cold in the north). Without the proper heat the compound can take up to several days longer than expected to fully dry. It will look dry on the outside, but not dry inside. The slow drying can cause cracks to show up much later.
Sorry that I don't have a fix, except to say BE PATIENT. I'd say wait a couple weeks before attempting any other sanding/priming or fixing. Let all of the cracks settle and dry properly, or it will just happen over and over like you are experiencing.
Best of luck.

jsnake

The more I think about it the more I think it is the extreme cold down there. There is no vent. I tried to get several HVAC companies to bid on adding a vent to the room but they all said it was too difficult to do.

At this point I am just trying to figure out a fix that will be quick, easy, and last.

pross

I have encountered the re appearing crack. Likely it is the temp swings you are dealing with.
Believe it or not I had a good experience with a spray on product called "Goodbye Cracks" I think it is made by the folks who make Goof Off.

It is basically an elastomeric spray to bridge the gap during expansion and contraction.

I couldn't believe it actually worked, but it did, and has lasted a long time.

Amos_Umwhat

I've done this kind of work part-time and for myself and agree with everything Bearb said. The caulk is the easiest solution, and done carefully will be un-noticable for several years, at which time, it will probably develop again, but you'll be about ready to paint anyway.

kingjk729

Barry is spot on and I will just add this .... If he used premixed mud the stuff that you can pick up at lowes or the home crepot those products will last a very long time in a sealed container because they put an additive in there ...... The downfall is they take a very long time to completely dry and cure. If you have a few fans put them down there and let them run..... Otherwise after they cracks stop growing caulk and repaint and you'll be all good.

MVW67

Use a urethane silicone paintable caulk, the elasticity will be the best. Take a sharp crayon and run down crack. Won't allow caulk to stick there and help the movement, then caulk will stop three sided adhesion when you do this, which is the reason most caulk fails.

jsnake

thanks guys. he came over to fix things today. will update you on solution

jsnake

Ok, so he came over and took an ice pick like tool and ran it down all the corners. That seemed to be the fix. No more hairline cracks. Seems the cold temps and the thickness of the mud in the corners was not allowing it to dry at the same rate. He asked some other drywall guys and my dad said the same thing.

The hairline crack in the ceiling was apparently caused by the primer. Easy fix.

I will post some more pics soon. Time for paint!