We have torn down a 75 year old two story porch and now plan to reuse the 5/4 fir T&G boards in our new addition. The old boards appear straight with no deterioration.  Although the new porch deck will be protected with a 2 foot overhang and will pitch for drainage, I have been warned that T&G porches are notorious for rot. We would like the best method to attach screen panels to the edge of the porch. Is there a  product or technique to create a curb under the screen panels to allow water to drain off and prevent insects from infiltrating through? Thanks.