I would like to install white pine shingles on my roof and also white pine clapboards ( 4" reveal ) for siding. I have read that flat sawn have a tendency to cup and 1/4 sawn split very easly. The shingles will be nailed on 1x6 spaced 5" to 6" depending on the length and reveal of the shingle.The attic will be unheated. Can shingles be dip treated for water repellant or should I leave plain? Depending on my budget,the siding may be nailed over 4" sips or 2" foam W/ vertical furring strips to provide an air space.Any comments would be appreciated, Thanks, John...