floating slab cracks

Hello. I agreed to the purchase of a home but am starting to wonder about some cracks in the basement. They are about a little bigger than hairlines horizontal cracks about 20 ft long. There are about 2 of them from one side of the wall to the other. I noted that it would be nice to know if they have been growing but as a buyer, there is no way for me to know. Any suggestions? How serious should I treat them?

 

blkczar402, Welcome to the DIY Forums.
There are all types of cracks. Some make no difference and some do. Check that your Home Warranty covers the floor. You should have one year to get anything wrong with the house corrected. Good luck.

 

They could be the normal shrinkage cracks that occur as concrete cures. The classic shrickage cracks are near the middle of the slab. These form a control joint breaking a slab that is too large into two (or four) reasonable size "slabs". All too frequently, concrete for basement slabs is too wet and shrinks more than good concrete.

Shrinkage cracks can also start at a corner or abrupt changes in dimensions or thickness which cause stress concentrations.

Crack measurement gages are available through suppliers to the home inspection businees. If your cracks are small it is difficult to tell if they are active or not.

Dick