NH, I use tamrack for sill instead of PT. I belive it holds up well, saw off the sapwood, sapwood is the rotty part. Same goes for pine, I use pine for exterior stuff just don't use the sappy parts on the exterior. As for old growth versus new growth perhaps we should view the sap wood as new growth and the heart as old growth, with the exception of growth ring count what is the difference? And besides there is nothing we can do about it. We are working on 3rd, 4th or 5th cuttings. It may be we have a bad opinion of pine because the mills send the nice clear sapwood to the building supply stores we buy it and than it rotts so therefore pine is crummy and don't use it outside. As I repeat myself I use my sawn pine out side and have no problems, no paint, stain or preservitives. Pine is the king of woods in my opinion, I enjoy working pine over any other. It is like butter, cream of the crop. Tim