Stone
- The natural slate is rigid and strong, like a piece of glass.
- The quality, color and longevity vary depending on where the slate was quarried. The main quarries today are in Virginia, Pennsylvania, Vermont and New York.
- Slate roofs are fireproof, strong enough to resist hail storms, aesthetically appealing and can last a century or even longer.
- They are mainly installed on steep roofs.
- The main types of slate in the United States are:
- Sea green slate - a long lasting roof slate that is also known as fading gray-green slate, for its fading color due to weathering. This is a hard slate from Vermont with a life expectancy of about 150 years on average.
- Purple slate – stays a dark purple color throughout its life. This is an excellent slate with a life expectancy of 150+ years and these roofs are highly restorable.
- Unfading green slate – an excellent light green slate that could last 200 years or more.
- Pennsylvania black slate - a softer slate roof material, last up to 70 -125 years.
- Peach Bottom slate - dark black, hard, and long lasting with a life expectancy of 150-200 years.
- Monson slates - also a dark black slate that is quarried in Maine and last about 150 years.
- Buckingham, or Virginia Slate – a gray-black slate with a life expectancy of about 150 years. This slate contains countless tiny silica crystals it hat gleam when viewed in the sun, a unique characteristic of Buckingham slate.
- NY Red Slate - a very high quality slate with a life expectancy of 150-200 years.
