Can I use composite piles for a house foundation that is designed for wood piles?
This one is easy. The skin friction of a composite pile is approximately the same as a steel pipe pile and is significantly higher than wood. The total vertical capacity of the composite pile is higher than the wood pile and approximates the steel pile. The lateral capacity of the composite pile equals that of a comparable steel pile and a few times higher than that of a comparable wood pile. I would think that if wood piles are successfully used for house foundations in your area that composite piles driven to the same depth would provide a much higher capacity. If the structural engineer or building inspector has any questions, I would be happy to contact him.