Staying Covered with a Good Roof

Most of us don't think much about our roof unless something goes wrong. But under the surface, there's a lot more going on that you might think--and some of those details can spell dollars for you.

Anatomy of a Roof

These days, residential roofs generally consist of three layers:

1. The decking or roof sheathing, which is a flat layer that goes over the framed portion of your roof and supports the weight of the rest of the roof. These days, it's often made of OSB (oriented strand board) or plywood sheathing, although older homes might use boards instead.
2. The underlayment, which is a layer that goes over the decking and helps keep water away from the decking below it. There's a wide range of underlayment types, including synthetic, self-adhered, and felt.
3. The covering, which is an outer layer that acts as a first line of defense against the elements. This is what people tend to think of as 'roofing materials,' such as asphalt shingles, tile, or metal.

In addition to these layers, roofs need vents to allow air to escape from inside, so heat and humidity don't build up within the attic and damage the roof. And finally, they need gutters and downspouts to allow water to escape the roof and return to the ground.

Replacing your Roof

It's obvious if you have water leaking into your home, but what about more subtle signs of roofs reaching the end of their life? We talked to Bill Ferrie with Minnesota Building Contractors to learn more. "If your shingles are cracked or curling or you see a lot of granular loss, if it's sagging, the roof's probably at the end of its expected life span."

Building materials have changed significantly even in the last twenty years. Twenty years ago, Ferrie shared that the industry mostly used 15-pound felt, whereas these days, there are more durable synthetic products available. There are even impact-resistant products that can help protect your roof from hail damage—and get you a discount on your homeowner's insurance.

Housing insulation has also gotten much better, and when it comes to your roof, that can matter a lot. Ferrie explained that on average, the air in your attic is 50 to 60 degrees warmer than the air outside—heat rises from the inside and your roof absorbs a lot of energy from the sun from the outside. Proper ventilation and proper insulation help keep your house warmer in the winter and cooler in the summer.

However, when you replace your roof, it's vital that you find a reputable, licensed roofing contractor. While a residential roof should last 20 to 30 years, Ferrie shared that he's seen many roofs that were wearing out at 10 years because it wasn't done right. "There's Mother Nature, but there's also improper installation. Every home has its own dynamics. A home that's 20 years old is a lot different than one that's 80 years old," he explained. Because of this, all roofers in Minnesota must be licensed. (See our post about contractor licensing for more information.)

Maintaining your Roof

A roof is a significant investment, so you'll want to make sure you maintain it. Gutters should be cleaned twice per year. If left long enough, water or ice can seep through the covering and underlayment and damage the decking beneath, which is a costly repair. You should also have your roof inspected every three to four years, or after a severe weather event.

Need help finding a roofing contractor? You can find a list of Rochester Area Builders members here.