Concrete strength ordered from the plant for each house. Large bell bottom gives solid support. Bell bottom anchors against uplift. Safety factor designed into each pier. No damaging forces on house during installation.
Owner can move heavy items in the house and add new ones without concern for the foundation.
Waiting time required to allow concrete to gain full strength. Improper construction will affect performance. Typically no soil test on site. Piling depth limited by wieght of house, so may not reach stable soil. No steel reinforcement in cylinders or cap.