Natural Stone roofs have lasted a century, giving excellent long-term value, in contrast to other types of manufactured roofing which must be re-roofed three or four times within this same period.
Slate is a natural, fine-grained, metamorphic rock that is formed under intense heat and pressure underground. That rock is then split into smooth, flat pieces to form slate roof tiles. Slate Roofing Tile colors, sizes and texture afford many architectural effects, contributing to the appearance and beauty of any home or building. If installed correctly, slate can serve as a watertight roofing system that lasts the life of the structure with minimal maintenance. The dense tiles can help regulate the temperature of your home and reduce energy costs. Natural slate tiles are also fire resistant and environmentally friendly. It is a natural and recyclable product, emitting zero toxic substances into the environment.
Disadvantages: As mentioned, natural slate tiles are extremely dense. They can weigh between 800 and 1,500 pounds per square (100 sq. ft.). This can pose a problem for homes that need a new roof, as typically they were not built to withstand this amount of weight. The expense of having a roof structurally inspected, and most likely reinforced, should be taken into account before having a slate roof installed. Another huge disadvantage is the high cost of slate itself, which may make it unattainable for many. Due to budget and weight constraints, emulates and alternatives have been produced, including synthetic slate. This product is lightweight and cheaper to install than natural slate; however, it is typically made of plastic and is relatively new to the market, so durability and longevity have not been proven.