I own and operate a small roofing company, Stewardship Slate, that specializes in the restoration and repair of slate roofs. We work primarily in the downtown area of Burlington, Vt., where more than half of the houses are roofed with slate—slate that was most likely quarried from a nearby region known as the Slate Valley. Running approximately 24 miles along the Vermont-New York border, this area has been and continues to be one of the largest sources of roofing slate in the U.S. (see map, below).

Ryan Catania of Stewardship Slate finishes up restoring a 120-year-old slate roof in Burlington, Vermont. Photo by Michael Dillon
Ryan Catania of Stewardship Slate finishes up restoring a 120-year-old slate roof in Burlington, Vermont. Photo by Michael Dillon

What makes the Slate Valley distinct is that slate found there comes in a variety of colors, shades, and textures. Green, sea green, gray, red, purple, and black slate come from this area, as well as slate in variegated mixes of these colors. Also, this slate has a reputation of being among the best in the world and is highly durable, lasting as long as 200 years. For our restoration work, we typically use salvaged slate from a couple of family-run slate companies located in the heart of the valley. The weathered salvage slates are a better color match and thickness (they are thinner than today’s standard) for the roofs we work on, which are almost all at least a century old. See author’s JLC July-August/21 article, “Slate Roof Restoration” for information about slating tools and techniques.

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The Slate Valley is one of the five major slate regions that produced slate in the U.S. (Monson, Maine and Peach Bottom, Pennsylvania-Maryland no longer produce roofing slate). Straddling the Vermont-New York border, this area has been and continues to be one of the largest sources of roofing slate in the U.S (left). The chemical and mineral composition of the slate in this region produces a variety of colors, which is unique in the world (right). According to the Slate Association, “Chlorite produces green slate, hematite the purples, carbon the grays and blacks, and hematite and iron oxide the reds. Slate can be known as ‘weathering’ and ‘non-weathering’, or ‘fading’ and ‘non-fading’ … the terms are often used interchangeably. Unfading slates more or less maintain their original color on the roof. Weathering is used to describe slates that would show various percentages of color change slowly as the slates were exposed to the elements.” Illustration (left) by Tim Healey, adapted from The Slate Roof Bible by Joseph Jenkins. Photo (right) by Tim Healey with permission from the Slate Valley Museum.
The Slate Valley is one of the five major slate regions that produced slate in the U.S. (Monson, Maine and Peach Bottom, Pennsylvania-Maryland no longer produce roofing slate). Straddling the Vermont-New York border, this area has been and continues to be one of the largest sources of roofing slate in the U.S (left). The chemical and mineral composition of the slate in this region produces a variety of colors, which is unique in the world (right). According to the Slate Association, “Chlorite produces green slate, hematite the purples, carbon the grays and blacks, and hematite and iron oxide the reds. Slate can be known as ‘weathering’ and ‘non-weathering’, or ‘fading’ and ‘non-fading’ … the terms are often used interchangeably. Unfading slates more or less maintain their original color on the roof. Weathering is used to describe slates that would show various percentages of color change slowly as the slates were exposed to the elements.” Illustration (left) by Tim Healey, adapted from The Slate Roof Bible by Joseph Jenkins. Photo (right) by Tim Healey with permission from the Slate Valley Museum.

Becoming a slater. I grew up in a town just north of Slate Valley and always had a passing awareness of it—my closest exposure came from playing high school soccer against the Fair Haven, Vt., “Slaters” and traveling through the area to visit family. Little did I know that this region would factor heavily into my professional life so many years later.

After college, I worked as a carpenter and then a construction project manager for 12 years before I got into the slate roofing business in 2010. I was always interested in historic preservation and there was a demand for slaters in the Burlington area. Although it’s somewhat dangerous work and requires a lot of patience, I’ve come to really enjoy the pace of slating.

A connection to the old country. A few years into running my business, I found out that my great, great grandfather was a slater in Scotland and I have family from the old country still in the business (Scotland, Ireland, England, and more famously Wales have pockets where slate is still the predominant roofing material). I now stay in touch with that side of the family via a fellow Gen-X-er Scotsman cousin who is a fifth-generation slater.

The roof slate industry along the Vermont-New York border began in earnest in the mid-1800s. According to the Slate Valley Museum in Granville, N.Y., “In 1839, slate deposits were discovered near Fair Haven, but quarrying was found impractical and uses for slate were limited. By the mid-1840s, things began to change, and a strong future for the industry looked promising. The roof of a barn one mile south of Fair Haven was the first to be covered with slate in 1848. It was feared the barn would not withstand the weight of the stone. The barn is still standing today and the same slate roof is intact.”

All labor was done by hand in the early days. Workers armed with hand shovels filled large, oak-plank boxes to move material. Steam power came to the valley a couple of decades later, then electric power in 1913 (both power sources helped ferry cut slate and waste pieces around the quarries with less toil). Eventually, air-powered tools such as jackhammers arrived and increased production many times over that of the early, punishing days of slate quarrying.

Today, the industry employs modern heavy equipment and adheres to strict safety protocols, though slate blocks are still split into roof slates with hammer and chisel, the one remaining task done by hand.