Many people are divided over whether to apply conditioners or oils to their wood shake/shingle roof systems to help keep them from drying and wearing out prematurely. While some say, “Wood is meant to age naturally, don’t apply anything”, others believe applying a preservative of some sort will prolong the life of the roof system. Down through the years, people have tried combinations of Turpentine and Linseed Oil, ‘roof oil’ (sometimes recycled motor oil), various ‘water sealers’ or chemical products to ‘put life’ back into their wood roofs. Most have real drawbacks but some offer positive results. Cost becomes an issue as it may cost $1000 or higher to apply material to the roof. Depending on the type of material used, reapplication will be necessary within five years. Costs can be substantial over time. That is a decision that ultimately only the homeowner can make. One thing is for certain, upkeep on a wood roof is a MUST if you want to extend its life, such as replacing missing shake-shingles, keeping valleys clear of debris, etc.