Can You Install A Metal Roof Over Asphalt Shingles? People have been installing additional layers on rooftops for decades – in fact, it used to be common practice and likely would have been considered wasteful in terms of time and energy not to do it. This practice is done less and less with asphalt on asphalt shingles, yet many people still find it acceptable to bury a shingle roof under a metal one.
Shingles Looking Worn? A Complete Cost Guide to Replacing Your Roof. You can expect your typical asphalt-shingle roof to last about 20 years, though climate factors like high humidity, heavy winds, and buckets of rain will cut that lifespan short. When you confirm your roof needs replacement — either by its age, an inspection, or signs of wear and tear — don’t delay this project.