Chevron Shingle Oil on Cedar Roof
Do you think it is valuable to apply Chevron shingle oil on a cedar shingle roof?
A guy who repairs roofs in our neighborhood full of cedar shingles wants to charge me $500 for spraying Chevron Shingle Oil on my roof every 3 years. I see a neighbor's rood that he just did which looks awesome. Another neighbor had it done a year ago and I can't tell at all. It looks very gray. Our roofs are 21 years old in this subdivision. I have read various cedar shingle industry brochures as well as reputable state university sources which state that shingle oil is not necessary for maintenance of cedar shingles. So I took a pass on this service and hired the guy to perform repairs on the dozens of cracked and missing shingles for $300. This is worth it to me because I can't find cedar materials at Home Depot and don't want to spend hours hunting them down at the specialty forestry products wholesalers (plentiful here in Boise, ID). Plus I would have to borrow belay equipment from my climbing friends and all that jazz to give me protection on top of a 2 story house.
I think I am doing the right thing with fixing the broken things instead of paying for cosmetic shingle oil application. But am I making a mistake? Will the oil hold of the inevitable roof replacement?