I am building a heavy duty treated wood fence, and many of the posts will be set in concrete. many people have told me that if you set a treated wood post in cement, it will dryrot and break off in less than 10 years. I live in MN, so there is plenty of moisture. This page, http://www.littletongov.org/communit...ncepermits.asp says to wrap the post in tar paper. any one have a better idea?