The walls and floors of your house are cracking does your home insurance pay for repair?

No. Unless the cracking is due to a covered cause of loss. Check your policy for a complete list. For example, if you carry Earthquake Insurance and the cracking is due to a recent quake, then YES there would be coverage.

There are also home warranty policies that can be obtained that cover maintenance items such as HVAC, Plumbing and you could look there for wall/floor cracking to see if its excluded, but garden variety Homeowner's Insurance will not cover any construction defect or maintenance issues. The intent of the Homeowners policy is to cover sudden and accidental loss even if the loss is not immediately noticeable, while the Contractor who built your home is responsible for building seaworthy homes and if he/she has failed to do so, inquire with them about a resolution, especially if the home is less than 10 years old. Most states require you to seek assistance and resolution from the builder before taking any legal action. This saves you mountains of time and energy to allow the builder to make repairs if they are willing to do so.