Just recently we were having a conversation with a company that pours our foundations. They had several call backs from another builder and were being told the foundations were cracking. We found this to be very strange, because this same company we are using have never had a cracked foundation on our homes. It all comes down to how a contractor properly versus improperly compacts the soils around the foundation. It was discovered that the other contractor was not waiting a reasonable period of time (5-10 days) in order for the concrete to cure properly as well as the compaction methods used against the newly poured stem wall. After a reasonable period of time, we methodically compact the material against the stem wall by hand, using a powered jumping jack. Probably one of the worst jobs in construction, but vital to making sure the foundation is protected correctly. Short cuts are just another way to create a disastrous outcome.