Dry Shrinkage in New House 1

[Melky]

Question/Questions....
New house foundation poured 6 or 7 months ago. House was 90% completed in mid June when construction stopped due to work restrictions during summer months.
Hammer Law in beach association. Everything was perfect at that point. During that time a dehumidifier was left running in the basement to try to keep hardwood flooring (above) from gathering moisture and cupping.When site was visited mid July a couple of small cracks where noticed. One under a window and one near an outside corner. Both small hairline vertical. No big deal. During the last couple of weeks more cracking pretty much all some what vertical. They seem to be popping up all around as a tiny crack at top of wall, some seem to be moving down the wall some don't. The first two cracks have made their way through wall, everything else is just interior surface so far. In June foundation appeared to be crack free. Hardened Dry Shrinkage that was delayed? Could the dehumidifier have caused this by pulling moisture out of the wall to fast? Could they have created an issue trying to resolve another? I know they put an additive in mix for curing and was told it hardened up pretty quick. Could that be the reason it is shrinking now? The dehumidifier has now been shut off. Walls cracking/hardwood cupping. Would epoxy injection of cracks slow them or create more?
House structure is fine, minus hardwood. Should this subside or is there more to come? Any Advice.............

 

[Ron]

Photos and sketches would be helpful; however, what you've described is fairly typical of drying shrinkage. Essentially all cementitious materials (concrete, masonry, mortar, stucco, drywall mud, etc.) exhibit dryinga shrinkage as they give off the excess water that is not needed for hydration (part of the hardening process). As the shrinkage occurs, stresses build up in the material and then get relieved when a crack develops. The most common locations for cracks to initially appear will be at window corners, door corners, wall corners or other wall variations. Floors work similarly, except that there are usually fewer penetrations of the floor so the cracks follow a slightly different pattern.

The dehumidifier, depending on its capacity, would contribute to the overall drying process, but the drying would eventually occur anyway, particularly when the house is finally closed in and the AC is operating.

 

[Melky]

Thanks-Ron
I know dry shrinkage cracks tend to be more of a cosmetic thing, than structural. I was thinking the Dehumidifier wasn't the cause but probably sped up the process.
There are many cracks, most really tiny or just starting. I was also thinking that by speeding up the drying process it could have increase severity of cracks.
Natural drying...the stress would be less. Will all these cracks run down to the floor level and transfer through to the outside of wall or will some stop in there place? Probably repairs should be put off til things stabilize as it could cause more cracking?? Trying to find some info on this type long term shrinkage, not a lot out there.
Could this become wide spread and lead to failure of foundation or will it typically follow the shrinkage of short term shrinkage after hardening. Possibly subside soon
with little impact to structural integrity?

 

[Melky]

I saw a thread start by miketheengineer that seemed to be a similar situation. Wondering what the outcome was???