You need to sink your piers to 'refusal depth" which is from about 12 to 29 feet here. They won't drive deeper than that. There is only a little dif between "Bedrock" and tightly packed sand down there.Most of the load will be carried on the sides of the pier, though intuition doesn't suggest that.Imagine pounding a big nail through a board and balancing the weight on that. Since the nail sticks out the bottom it carries no load, but the nail is in solid anyway.

Last edited by Dane; 03/27/10 12:36 PM.