Q: The red cedar clapboard siding on a house in the Boston area was not backprimed and has typical moisture-related paint failure. It has been painted five times in 25 years. The house has no interior vapor barrier. I am considering removing the siding and installing new backprimed clapboards over a vented rainscreen. Will the rainscreen installation solve the problem of premature paint failure, or must I address the lack of an interior vapor barrier?