Metal
Metal rooftops were once relegated to sheds or barns, but are now available in various sheet and tile options for residential houses as well. Homeowners can choose between aluminum, steel, zinc and other metals. The metal rooftops must usually be placed over a mat to prevent moisture from leaking down into the roof.
Fiberglass
Fiberglass is a synthetic material made of glass strands that are woven together and hardened with an additional coating. Some types of fiberglass roofs are made into sheets or planks, while other kinds can be formed into tiles of various textures and sizes. Some fiberglass roof materials also use asphalt as a coating to help protect them.
Cost
Metal and fiberglass rooftops can have similar costs, but in general fiberglass materials are less expensive, costing between $100 and $350 per square foot. Metal roofing starts higher, at around $150 per square foot, and, depending on quality, goes up to $600 per square foot. Metal roof installation costs also tend to be higher than fiberglass.
Durability
In the short term, fiberglass tends to be more resistant to acidic rain, dirt and heavy impact. Metal rooftops, on the other hand, can be damaged by rust, especially from under the roof where moisture can seep upward. However, if the metal roof is installed correctly, then it will resist rust and can last 50 years or longer, while fiberglass rooftops typically last 20 to 30 years.
Energy Efficiency
Metal rooftops reflect sunlight, keeping houses cooler in the warm summer months. Fiberglass roofs tend to absorb heat, making them more ideal for colder climates where absorbing heat is beneficial. Metal rooftops are often designed to save money in warmer months and may even be a tax-deductible project for their energy conservation. Regulations for metal rooftops depend on state and federal laws for the year they are installed.
Maintenance
Metal rooftops tend to be easier to maintain than fiberglass roofs. The metal can be cleaned more easily and is more resistant to long-term staining. Fiberglass rooftops have more places for leaks to develop and can collect dirt more easily than many types of metal roof materials.