Quarrying & Production

The Slate Valley of Vermont runs north-south in the far western portion of Vermont, along the New York border. This Valley holds some of the highest quality slate in the world, but it takes a number of highly-skilled craftspeople to turn this natural, raw material into the finest slate roofing you can find.

Quarrying

Slate is extracted in open quarries. We use heavy equipment to uncover the slate deposits and then rock drills create vertical holes in the slate, usually along natural joints in the beds. We then place a precise explosive charge into the holes to separate usable blocks of slate. This is where we find the first craftsperson in our process. A good Pit Leader is able to read the beds of slate to know where the best stone is located, work around imperfections in the quarry, and extract the best slate blocks while minimizing the cost and waste.

Milling

From the massive slate blocks, the blocks are further subdivided and then hauled to the slate mill. At the mill, our second craftsperson comes into the mix. Sawyers at the mill examine each block and determine precisely where to cut the stone to best utilize the slate. Diamond-tipped saw blades cut the irregular blocks from the quarry into specifically-sized rectangles.

Sizing & Finishing

After cutting, Splitters—the most skilled craftspeople in the mill—receive the blocks and use a hammer and chisel to split the slate from the ends lengthwise a number of times until the slate “chips” are the desired thickness. Good slate requires a very specific combination of mineral components, pressure, temperature and time to create its natural cleavage planes and not all blocks of stone split uniformly.  Splitters mix art and science to finesse uniform, smooth, ¼” thick pieces of slate from the cut, but still fairly raw, blocks.

Chips—what you might call slate roof pieces—from the Splitters go on to the fourth craftsperson in the process, Trimmers. A trimmer’s job is to remove any imperfections that may adversely affect the appearance or performance of the slate, while maintaining strict controls on the squareness and dimension of each piece.

From the Trimmers, the slates go to the final craftsperson, the Puncher, at a punching and packaging station. Here, nail holes are punched or drilled in each piece and a final quality check is performed before the slate is stacked on a pallet and banded for safe transport to the jobsite. Punchers inspect each piece by “sounding” them—gently striking each piece of slate with their palm to identify and remove any pieces with hairline cracks.

Each step in this process is critical to defining and crafting high quality roofing slate.  At New England Slate, we employ the best craftspeople to ensure our expectation and culture of quality is present in every piece of slate we produce for you. The stone we use comes from nature. The New England Slate difference is in how we handle it—with care and craft—from the quarry to your home.

Contact us to learn more about how we can incorporate this beautiful material into your home or building, today!