Roofing Materials- Covering the Basics

Talk about one of the most overlooked parts of your home. The only time anyone thinks about their roof is when something happens to it or when start to have mold on it. You may find that yours leaks when it rains, or a storm may have blown off part of your roof. Or, you may be looking over your house and notice that you have curling shingles and others missing or loose. However, you get around to looking at your roof, its good to know what is out there to replace it with when the time comes.

There are several categories of roofing materials, but I think I will use my own today. These are Period (including architectural style), Standard, Alternative, and New Technology materials. Each has its place in the overall look of your home. Some even cross over and you can have New Technology that looks like Period materials. That is the best of both worlds…of course, it will be a bit more expensive, but that is how these things go.

Standard Materials

When you look at the roof of a house, you expect to see this type of material. Standard roofing is most often composition or asphalt shingles. These are made with either a felt core or a longer lasting fiberglass core. Fiberglass core shingles have a Class A fire rating and are good for homes in areas where wildfires can be expected, while felt core are Class C. (Information on fire ratings can be found at the end of this page.) Shingles weigh between 215 and 300 pounds per square, which is 100 square feet, and have an average lifespan of 15 to 30 years. Heavier weight shingles with a fiberglass core last longer. Shingles come in a wide variety of colors, tab sizes (the part that shows), textures and edges (straight, wavey, or rough for instance.)

Other types of standard materials are wood shingles, wood shakes and rolled roofing. Rolled roofing looks like the asphalt shingles, but without the tabs. It doesn’t last as long because there is only one layer of rolled roofing compared to three layers with asphalt’s overlapping tabs. Rolled roofing comes in two basic types…full-width mineral surface and selvage-edge. Full-width mineral surface comes in rolls three feet wide and 36 feet long. One roll will cover one square. Selvage-edge is also three feet wide and 36 feet long, but it takes two rolls to cover a square because you need to overlap it by half its width. Both weigh 90 pounds per roll.

Wood shingles and shakes are usually made from western red cedar. Shingles are smaller, lighter and thinner than shakes and are sawn on both sides. Shakes are split by hand and maybe resawn on one side. Because they are thicker and split by hand, shakes are more expensive. Shakes and shingles are graded by number. The best grade is 1, followed by 2 and 3. Grade 1 is used for roofs because it is cut from heartwood and free of knots. Grade 1 shakes and shingles should last between 20 and 25 years, with shakes lasting longer because of the extra thickness. If you plan to use shakes or shingles, make sure your local fire code allows their use and look into having them treated with a fire resistant treatment.

Period and Style Materials

This category is fairly wide open. It ranges from shakes and shingles to clay tile. We have already covered shakes and shingles, so next is clay tiles. As the name implies, these tiles are made out of clay and are usually seen in homes with a Spanish influence in the Southwest United States. They can also be found in homes of the Prarie style found in the Midwest United States. Clay tiles are very heavy (over 1000 pounds per square, and more when wet) and need extra support. Clay tiles come in two basic styles…S-shaped and barrel-shaped.

Newer technology is coming into wider use for period roofing. Tiles made of cement are gaining popularity. They are lighter than clay tiles (750 to 900 pounds per square), come in a wide range of styles and colors, and can even be found glazed. Again, roofs will need extra support when installing cement tiles

Another type of period roofing material is slate tiles. These are split from larger pieces of slate, just as shakes are split from logs. There are also very heavy, in the area of clay tiles, if not heavier. Slate comes in many different colors and can vary in color from tile to tile.

Alternative Materials

Metal roofing has advanced to the point that you would have a hard time telling it from other types of materials. Steel and aluminum roofing comes in many different colors and styles. Metal roofing is best installed by professionals, as the seams are often welded. There is even a metal roof that is strong enough to span rafters without the need of wood sheathing, which will save time and money.

Tar and Gravel Roof

If you have a flat roof or one of a very little slope, a tar and gravel roof is usually the way to go. Layers of roofing fels and hot tar are applied to your roof and small pea gravel is spread over the final layer of hot tar. These roofs require professional installation and last about 15 years.

This is my favorite type of roofing material. I read about it several years ago and I am waiting for it to become more widespread. Standard asphalt shingles have been joined with photovoltaics (or solar energy collectors). Each shingle is a small solar collector which, when connected to the others on your roof, provide your home with solar powered electricity. While more expensive than regular asphalt shingles, this roof will pay for itself as the years go by. I have not seen much information on this technology lately, but as the cost of solar-generated electricity drops more in line with electricity generated from fossil fuels, we will be seeing more of this.