Slate Roofing: Will History Repeat Itself?

A reprint of an article published by Brian Stearns, the president & founder of Alpine SnowGuards, in Slate Roof Quarterly.

Will History Repeat Itself?

Back during the early 1970’s a sharp rise in oil prices sent a wave of fear and frustration through the U.S. consumer base. That “Oil Crisis” had a huge impact on the roofing industry. We Americans were swimming in a world of asphalt-based roofing products. Not only were we using hot tar for flat roofing and asphalt shingles for “steep slope” roofing, “trowel consistency” tar had become the preferred method for most roofers to repair slate, tile, metal, and any other roof surface that might show signs of wear. If you didn’t have a tar kettle in your storage yard and a half full, 5-gallon bucket of trowel consistency waterproofing in the back of you truck (lid bent and spread open to allow for the application stick), how could you possibly consider yourself a roofer? Ask any roofer who was in business back in the early 70’s if they remember the effect that the oil shortage had on their business. I’ll bet they will say that it taught them to qualify their bids based upon unanticipated increases in material costs and to consider all roofing materials.

The sharp increase in material cost for petroleum-based products caused both planners and consumers to investigate alternative roofing materials. Not only had the cost of asphalt-based roofing products increased significantly, it was understood that within 30 years (for the most part) the roof would need to be replaced. To put things into a relative perspective, most of the asphalt-based roofs that were being installed during the last “Oil Crisis” are now in need of replacement.

Slate was known to be the most cost-effective roofing material when considering life cycle. In fact, except for the fire-resistant qualities of slate, life cycle costs were about the only positive sales point for slate prior to the “Oil Crisis”. An “S-1” quality slate when properly installed is thought to be a 100-year or “life time” roof. Prior to the “Energy Crisis” most people didn’t seem to spend a lot of time considering life cycles of roofing materials. It was accepted that asphaltic products would wear out in 20-30 years but it didn’t matter. Replacement cost was cheap compared to the cost of a new slate roof and almost anyone could install asphalt shingles. Not true with slate. Due to our dependence on oil and the belief that it would never run out, the construction industry had developed a throwaway mentality when it came to roofing products.

The slate roofing industry is an extremely difficult industry to keep track of. Based solely on bits and pieces of information, it is estimated that during the early 1970’s, somewhere in the neighborhood of 15,000 squares or less of roofing slate were quarried and shipped out of the New York/Vermont slate region annually. At that time the area had the depressed feeling of a bygone era. But as oil prices began to rise all of the petroleum-based roofing products began to increase in cost. The cost of slate did not rise. Building owners and architects began to reconsider slate as a long term, cost-effective roofing alternative. Throughout the 70’s and into the 80’s slate roofing experienced a revival. As a “best guess,” by the year 2000, the New York/Vermont slate region was shipping in excess of 100,000 squares of roofing slate annually. Add to this the number of squares of slate being produced and shipped from Canada, Spain, China, Wales, Etc. to the U.S., who knows how much is being sold and installed in the U.S. market today. Maybe 150,000 squares annually? The “Oil Crisis” of the early 70’s was truly a boom to the slate roofing industry.

Today the slate roofing industry is thriving when compared to the state of the industry in the early 70’s. The New York/Vermont slate region has the feeling of a thriving area. Production is up and production techniques are modernizing. Like most industries, this has an interesting effect on prices. When I started installing slate roofs back in the late 70’s roofing slate was selling for approximately $300.00/ square for standard thickness weathering gray or green slate. Today the price is almost the same. How many construction-related products cost the same today as they did 25 years ago?

Is it possible that the latest oil crisis will create the next boom in the slate roofing industry? We as consumers will want to watch this roofing material market very closely. Several other factors this time around may make slate even more appealing:

There are slate roofing installers available today who know what they’re doing

In the early 70’s very few roofers were still installing slate. As a result, very few new and young roofers knew anything about proper installation technique. Most of the installers who really knew this trade had either retired or passed away. If you were interested in having a slate roof installed, lots of luck! Sure, you could buy the material, but finding a good installer was, at best, difficult and even the bad ones were expensive. The good news is that this is no longer a major issue. Good installers are usually busy, but they are out there.

The material cost has not risen since the 80’s. This is due in part to the economy of scale and advanced production techniques. However, it may also be the result of pressure from imported materials. Roofing slate is produced all over the world. There are concerns about quality and accountability related to imported materials. Assuming that these issues are addressed and dealt with before the material is installed, some of the imported material may be a good alternative.

Synthetic slate is another factor that is likely to be have a significant impact of the cost of natural slate. Throughout the 80’s and 90’s some very clever entrepreneurs saw the opportunity to create synthetic slate roofing materials that were less expensive than natural slate. To their credit, some (not all) of these synthetic materials were excellent in appearance and quality. It is my opinion that these synthetics began to put a real pinch on slate roofing producers through the late 90’s and into 2000 as the consumer took a step up from conventional composition shingles. I believe that over the past 30 years (but especially the past 10), consumers, specifiers, and roofers have become better educated and enlightened as to the use of these higher quality roofing products.

Like most things, the construction industry has changed a great deal since the early 70’s. There are more strict safety precautions that must be adhered to, expensive and escalating insurance cost, more expensive and often high tech underlayments, and the addition of ventilation systems that for the most part didn’t exist prior to the 70’s oil crisis. The point is that when you consider all of the factors related to the proper installation of any “Steep Slope” roofing material today, the actual material cost is not as big a part of the overall equation as it was back in the 70’s.

This time around, there is another interesting factor that could benefit the slate roofing producers. The metals market is high at the same time that oil prices are high. Building owners who may otherwise have considered metal as a roofing alternative are also begin to consider other alternatives.

Remember the statement that “slate was known to be the most cost-effective roofing materials when considering life cycle”. This was known to be true back in the 70’s. Today, when considering all of the factors that go into the cost of a “Steep Slope” roof, not the least of which is the increased cost of petroleum-based shingle products, natural slate may again be the most cost-effective roofing material available.

Think twice as you plan your next roofing project. Consider all alternatives. The cost of a slate roof may no longer be out of reach.

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Alpine SnowGuards designs, engineers, and manufactures snow management systems from our facilities in Morrisville, VT. We work closely with leading roofing contractors, engineering firms, developers, solar installers and roofing manufacturers to ensure we deliver quality products that do what we say they’ll do. Alpine SnowGuards can help a building qualify for LEED® credits

(Images from:, Shutterstock and Traditional Roofing Magazine)