Let’s say you bought a lot and you want to start building on it. Your excavator digs the hole for the foundation. Your cement contractor pours the concrete for the footings.
After that the block are set in the hole.
That weekend it rains. Monday morning you get a phone call saying your footing are destroyed.
What happened? You’ve built your foundation on untested soil. If a core sample (hole bored in the ground 10′-12′ below the surface) were taken before you started you would have found out that;
You’re building above an abandoned septic system, rock pit, buried logs, and or stumps, an old dump site, modeling clay, or even an under ground river. All this can be fixed by at a high price.
Another good reason for a core test is it should tell you the water table of your ground water weather to use damp proofing or water proofing systems on your foundation.
With a area of high water table (example you want to put in a full basement about 8′ below grade and the water table is at 2′ below grade with no proper water proofing your basement shall have 6′ of water in it before the year is up.) Choice the right style and foundation to handle a high water table and the hydrostatic pressure it shall put on your foundation. Remember when water freezes it expands, If you are using block and the water is on the face or even in side the block when it freezes, it will blow off the facing of your block. Each winter it starts over. 3-8 years later your out side face of your block is gone. Don’t worry the block will notify you when the face is gone the water will run in to the block and across your basement floor. The next winter is the worst if not repaired the frost will blow out the webbing in the block than you will now have a structural problem.