News

The Nature and Characteristics of Slate

Slate is a microcrystalline, fine grained metamorphic rock formed 400 million to 550 million years ago. Sediments accumulated on the sea floor were exposed to extreme pressures which lead to the chemical and mineralogical transformations you see today.

read more

6 Basic Principals of Slate Roofing

Generally the steeper the roof, the better with regard to service life of slate. Anything above a 8:12 is preferred, and slopes in the 12:12 to 18:12 range are probably ideal. Not only will slate shingles last longer on these steeper slopes, but they will be more visible from grade and show off their natural beauty.

read more

The Manufacturing of Slate

Slate manufacturing begins with the stone. Close to the surface or hundreds of feet deep, the metamorphic deposit must be excavated. A combination of blasting and the use of enormous quarrying machinery is used to prize the rock from the ground. ...

read more
NSA Mission
National Slate Association’s Mobile Field Guide
Subscribe to our Newsletter