I live in a log home built 25 years ago and it has a pier and beam foundation. The under pinning is currently of treated plywood which has "bowed" in many places. The bowing has caused the joint where the two pieces of plywood meet horizontally to be out of alignment and now frogs, snakes and other critters can squeeze between there and get under the house. The underpinning is attached to the outside frame of the foundation at the top and dirt pushed up against the bottom of the plywood to hold it in place.
How do I properly put in a correct underpinning? I was thinking about using a concrete board made my James hardie. I can attach the concrete board at the top of the foundation, but how do I handle the bottom of the board at the ground? Do I have to build some sort of frame? Do I try just burying the new board, or do I need to put some sort of footing down that the board will but up to at the ground? I don't want it to bow like the other underpinning did and more importantly I don't want anything to get under the house.
It is really important that I do this right. I was bit by a copperhead snake that lived under the house by day and came out at night when it was cool and bit me on the foot.
Can anyone help me with this project plan?