Homes have many components. Basements or crawl spaces, siding, windows and doors, kitchens, electrical systems, security systems, flooring and floor covering, closet space, plumbing, bathrooms, landscaping, and more.

But there’s one part of a home that stands out, literally and figuratively, as exemplified by a common phrase parents often employ with teenagers and young adults. “As long as you live under my roof …” Parents don’t say, “as long as you’re using my bathroom.”

A roof is a home’s capstone. It is exposed to all sorts of weather – pouring rains, heavy snows, a beating sun, ferocious winds. Not for nothing after a hurricane or tornado do news crews typically focus on shots of homes that have lost their roofs.

It is rather amazing that the rule-of-thumb for a roof’s life expectancy is 20 to 30 years, considering the beating…