I am restoring a farmhouse built in 1810. The sills have been repaired along with most of the first floor joists. The exterior is sheathed in American Chestnut planks. I am planing on removing them and sheathing the house in Plywood. We plan an making moldings/shelves... with the chestnut. What thickness and type of plywood should I use. I here conflicting reports on RTD vs CDX. What is the difference. We would like to make the house as strong as possible so it will last another 200 years! I will not use OSB or particle board!!!