Residential Roofing Basics
The purpose of a roof is to protect the valuable assets inside a home or business from being damaged by the elements outside. That protection can be provided by a flat roof or a sloped roof. Usually, flat roofs are used on commercial buildings and sloped roofs on residences, although there are exceptions.
Roofing materials are applied to a substrate on the top of a structure. This substrate is usually felt, either 15 or 30 lb., covering the roof decking, typically plywood, which goes over the rafters. Roofing materials are often provided or priced based on a square, which is a 10′ x 10′ square area of roof, or 100 square feet. The types of materials used vary depending on the type of roof and customer choice.
Standard composition shingles or fiberglass/asphalt shingles. The most basic of these is a single strip, three-tab shingle, which comes with a 15-, 20- or 30-year warranty. Upgrades to this basic product are architectural and designer or specialty shingles, which are now the familiar 30-year shingle. 30-year shingles, as of 2011, are limited lifetime warranty shingles, meaning they should last about 50 years. Will they really last that long? Maybe not. Why does the manufacturer guarantee them for a lifetime? Because they assume a hailstorm, windstorm or other disaster will happen within 50 years—and someone else (like an insurance company) will pay to replace the roof.
Metal has become more competitive with composition shingles as the price of oil has continued to rise. (The asphalt in composition shingles is an oil product.) You may see metal roofs without realizing what they’re made of, because they don’t just come in the traditional, long, smooth strips any more. Now you can get specialty metal roofs with shingle shapes formed in the metal and coatings that make them look like expensive composition shingles. These usually have a layer of stone topped with a layer of granules.
Metal makes a very viable roof system and, unlike in the past, neighborhood associations will probably allow specialty metal roofs. Also, the shingle pattern and the granules on these specialty roofs significantly diminish the old problem with noise (from rain or, say, acorns falling on the roof.)
This is the most expensive option for new roofs and it’s not used on much new construction in our area. A specialty product, it can last forever if installed properly and maintained professionally. The stone is quarried about 3/8″ – 1/2″thick then cut down into tiles. Most of the slate used for these tiles comes from Vermont, so it’s much more common in the Northeast.
Terra cotta Tile
Terracotta tile, the kind you see on American Southwest mission-style homes, is man-made, formed clay tile. It’s very expensive in our part of the country, because it’s heavy and costs a lot to ship. That’s why it’s used mostly in the Southwest and West, where most of it is made. Terra cotta isn’t as long lasting as slate but it can last 100 years or more.
You may not realize that gutters are an important part of the roofing and water drainage system of your home. They keep water from falling straight down from the roof and move it as far away as possible from the house. The gutter downspout gets the water to the ground, then a kick out gets the water off the roof and away from the house, preventing damage to your home’s foundation. Improperly installed or maintained gutters can cause damage, not only to your home’s foundation, but also to your roofing system and the exterior of your house.