While slate's popularity as a roofing material peaked around 1900, you can still put in a slate roof today. The United States, Africa, Europe, Australia, China and Brazil all produce roofing-quality slate. Slate is a beautiful and natural roofing material; its composition makes it both fairly brittle and long-lasting.

Composition

Slate roof tiles are made from slate, a naturally occurring stone. Slate comes in gray, green, purple, black or red; you can also find variegated slate that blends these colors. Slate is composed of clay and mud that solidify over time into quartz, mica and chlorite.

Durability
Roofing slates comes with a grade that indicates how long it will last. According to Durable Slate, a grade of S-1 means a life expectancy of 75 years or longer. S-2 slate lasts 45 to 75 years and S-3 slate tile will last up to 45 years. As Durable Slate notes, many slates outlast the time frame on their grade.

Cost
Durable Slate estimates that slate roofs average $10 to $40 per square meter, depending on the grade of slate used.

Installation
During installation, slate shingles traditionally get pounded into your roof with nails. Since slate cannot be bent, most slate roofs have steel or copper flashing that cover these corners and odd angles. Ask the Builder notes that a new technique allows slate roofing to be installed on a track, meaning that you don't need to use nails.

Warning
Slate's downfall is the naturally brittle nature of the stone If you drive the nail to deep (or too shallow) during installation, the slate slab shingle can crack and fall off your roof. While your slate roof won't need much maintenance, shingles can crack when people climb on your roof to clean your gutters or chimney. Freezing cold cycles also may cause slate shingles to crack.