I don't recall where I saw it, but there is a product (similar to door & window flash, but wider) that goes on the plywood, along with a primer. You would need to start the application down at the ... read more
Dan, Both Hardie Plank and a 3/4" and 1.5" insulating foam board are good options. There is also the choice of using Insulated Siding that is a custom contoured foam backer. It fits to the specificati ... read more