Roofing Materials: Taking It From the Top
When selecting a roof for new construction, or replacing an existing roof, there is a wide variety of roofing material to choose from. All have unique advantages and strong points. Some also have drawbacks. Here are some examples of roof materials and their attributes.
Clay roofing tile is among the oldest and most durable of roofing materials. It gains its weather resistant, fireproof and insect-proof qualities from being made of kiln-fired clay. Most people think these tiles are limited to the barrel-shaped type. But they can be flat, and they may have a glossy surface. They are also available in blue and green, aside from reddish brown.
Metal roofing is available in the widest range of materials, combination of materials and configurations. It is fastened in a variety of ways and comes factory-finished with various coating systems.
The most common types of metal roofing: steel panels with exposed fasteners, steel panels in which the fasteners are hidden, and rust-resistant aluminum panels that look like shakes, shingles or tiles.
Regarding rust, steel panels achieve corrosion resistance with a coating of zinc (galvanized) or a mixture of zinc and aluminum (known as galvalume or galvan). Top-quality steel panels have both zinc and a factory-applied coating.
Wood roofing in the old days was essentially the same product as it came from the tree. Today’s is more sophisticated.
Cedar roofing can be factory-treated with chemicals to boost its fire rating from Class C to Class B. Southern yellow pine shakes are pressure-treated to help them resist rot and decay, and although these shakes have been on the market for five years, their manufacturers expect the product to have a 30-year life span. Likewise, a composite wood shingle has been on the market for 15 years, and its manufacturer says it has substantial weather resistance.
Shingles are smooth and uniformly shaped; most shakes have a rough, uneven texture. Shingles are one-half-inch thick; shakes can be one-half-inch or three-quarters-inches thick.
To get maximum durability out of a cedar roof, roofing contractors recommend cleaning it with a pressure washer once or twice a year to remove moisture-holding debris and apply preservatives.
Slate roofing is available in two types--premium clear pieces and ribbon slate. Ribbon slate is not as durable as the clear premium product. It is distinguished by the ribbons of light color that run across its surface. The ribbons are weaker than the surrounding dark areas.
Slate comes in gray, purple, green and red. Properly installed, it has incredible durability.
