Depending on the thickness and quality of the product, climate and maintenance, a cedar shake roof should last up to 30 years. Thicker, premium shakes tend to last the longest. Keep in mind that the primary waterproofing is from the strips of roofing felt that alternate between each course of shakes or shingles. Assume that water, especially wind-driven rain and snow, will get between and under the shakes. Their primary job is to protect the felt from wind, impact and the sun damaging UV rays. If felt “keyways” are left exposed between the shakes, they will deteriorate and leak.