Some of your considerations should include lifespan, maintenance, and how green a roofing material is.
The expected lifespan of the roof is important because, while initial cost is an important consideration, if you could pay 30% more for a premium roofing material that would last, say twice as long, the end cost is less for the better product.
Next is maintenance – do you want a roof that will require periodic maintenance, or are you looking for a roofing material that won’t need to be touched until it needs to be replaced again?
Finally, green is an important consideration for many people today, and you’ll find that some materials are fairly green, while others are anything but.
So, with those considerations in mind, let’s cover the most popular materials:
Composition (asphalt) shingles – Composition shingles are widely used as a roofing material. They are inexpensive, fire resistant, and easy to install and repair (which saves on labor). Styles and colors are available to suit almost any home type, from the least expensive 3-tab shingle which you see frequently, to a premium architectural shingle featuring shapes and dimensions that might make them hard to identify as asphalt shingles. The downsides include a shorter lifespan (10-30 years) and a very low green score.
Metal roofing – Metal was once a very popular roofing material, with zinc, copper, and lead roofs being common. Today, we’re seeing a resurgence of metal, this time with steel, aluminum, copper, and tin being used instead, and in either standing seam or shingles. Metal is one of the sturdiest materials you could choose for your roof, it’s fire retardant, and mostly maintenance free. It’s also a great green choice, as it absorbs far less heat than an asphalt roof, heat which then transfers into your attic and drives up your energy bills. Metal roofing also gets green points for being 60-65% recycled material. The biggest downside is the cost, which is substantially higher, though this can be offset by the long life of metal (50+ years).
Wood shakes – Wood certainly has a lot of character, and it weathers nicely. Wood roofing also has energy benefits, as they allow the home to breathe while insulating the attic. The downsides include fire danger, shorter lifespan, and high maintenance. Green points are neutral – while natural, they have short lives and are not reusable.
Clay tiles – Clay tiles are a beautiful roofing option for homes where the style would fit (Mediterranean, Italian, Spanish, etc.). They are fireproof, long lasting, and low maintenance (plus green if clay is local). The downside is their specific style, the high cost, and their weight (some roofs need added support).
Slate – Slate roofs are beautiful and have a very distinctive look. They are fireproof, long lasting, low maintenance, green, and their style has wider applications than clay. The downsides are that slate is expensive and heavy, which may call for added roofing support.
Concrete – Concrete has been getting more and more applications recently. It can be made into almost any shape, style, and color. It’s recyclable (green), relatively light, fire resistant, low maintenance, highly durable, and long lasting. The primary downside is a higher cost.