That changes things! Anyone who attempted to level a floor by placing jacks on non-supporting concrete may also have misread what was necessary to level the floor in the first place. In other words, putting the posts in correctly may not solve the problem. You really should have the house looked at by a local expert--engineer, architectural technologist, framing carpenter--before attempting any fix. These "This Old House" segments, part 2 and Part 3 cover the topic in some detail. The fact that the posts have sunk two inches shows they carry a substantial load and are likely at the right place, but not properly supported. But best to get an on-site opinion that can take all factors into consideration. Best of luck! And don't just let it go.

In general, builders will tell customers that nearly any concern is 'normal and not covered by warranty.' If they can keep you unconcerned long enough, and lull you into not keeping good documentation, the warranty runs out, and if you persist they may say they were not notified of the problem during the warranty period. Been there, done that, but in another state. You'll need to find out what your state requires of builders as far as a warranty of their work, plus what the statute of limitations are for construction defects. The two things can be entirely different. You will need to have a competent, unbiased, structural engineer look at suspected foundation failure most likely, because home inspectors do not necessarily have the education and license to advise on engineering issues. Document everything. Hopefully you have a paper trail showing you notified the builder of this concern before any important deadlines ran out. If you have proof you attempted to start a warranty claim or concern, in time, it can be very important. Many lawyers will tell you that there's not enough money in your case, even if it's a valid case, so they won't help. If you find a lawyer who will help, and who's good at his/her job, you're ahead of where we were. We had over 30 lawyers tell us that we'd probably win but never collect, so they would not get involved. We just had to learn for ourselves what to do. Several years later we settled the case. But it was about all I had time or energy to deal with during those years. So it is possible to fight and win and even collect, but if it's not "worth it" to a law firm you will find yourself going it alone as far as legal help. I strongly recommend you use the info available on two consumer organization's sites: HADD.com and HOBB.org. This is really the only kind of place I got the info I needed to help myself. Good luck, I hope that it IS only minor, but you have to be sure, and that will require spending some cash on at least an inspection by someone qualified in foundation failure. Then go from there but be sure to document everything no matter what.

jal, Drylok will not work unless you make the crack wider. This happened to me in a house I used to own. I used a hammer drill and made the crack wider, at least a 1/2" wide. Then I filled the crack with drylok... it worked. Not a clean job though, try to keep the floor wet were your working, it keeps the concrete dust down. There might be an easier way to get the crack wider but this worked. Also, when your all done find out where outside the water is draining to the house and change the grade so it doesn't anymore.... course 9" is a lot of rain.... Thanks Dave

Best way to do this is to chase the crack with a chisel and clean up the edges. Buy 1/4-1/2" closed cell backer rod, you can get it on amazon for $6. Put that inside the crack along entire length about 1/2" deep and in the same place you can order and get Quikcrete Cement Crack Filler (home depot might be cheaper for this item) You can also use Sika or Quikrete self leveling concrete filler it sold in most Home depot stores HD also sells the backer rod, but I'm not sure if they have 1/4" or 1/2" I think they only have 3/4"... just make sure to get the one intended for concrete not windows (frost king brand), it would be Sika brand usually, they would know "hopefully". Good luck