A slate roof is a gift from one generation to the next – a roof crafted with excellence

I write this post as the President of the National Slate Association, whose mission is to promote the use of natural slate in North America. I am biased. Photo credit to David Armstrong of Rudd Builderz.

Slate tools have been part of the Stortz tool line for over a hundred years, so the material holds a place in our hearts. Spreading awareness that natural slate is the finest roofing material worldwide helps continue this historical tradition in the USA. The industry faces hurdles year after year and this post will outline issues to give a better understanding of what to expect moving forward. Where to begin?

The Issues

• Qualified Contractors – Poor slate roof installations destroy the reputation of the material. If a slate roof leaks, it’s not the time tested material, but most likely reasons that range from improper headlap, under or over driven nails, or poor flashing to name a few. The NRCA, National Roofer’s Contractor Association has developed a course that tests a slater’s skills. If they can become “ProCertified”, which involves passing an installation test, they prove they are qualified installers. The idea being that specifiers may eventually require that slate roofs be installed using “ProCertified” installers. This should enhance the quality of installs and avoid damaging slate’s esteemed reputation.

• Training – How does a newcomer learn how to install a slate roof properly? Commonly this information is passed down generation to generation, learned on the job, or through the roofing contractor’s in house training. Fortunately, the Slate Roofing Contractor’s Association has developed training to prepare slaters for proper installs. They have a curriculum that spans from basic to advanced levels. This training ties into the ProCertification as roofers can learn the skills necessary to pass the NRCA exam. It’s important to know that this type of education is available.

• Supply – Understanding that slate is still being quarried dispels any production myths. There has been some manufacturing consolidation over the years, but there are still producers investing in roofing slate. These are the main areas of supply:
  • Vermont/New York region known as the slate valley and produces varying colors of slate
  • The PA quarries in Slatington & Pen Argyl produce “Penn Black”
  • Arvonia region in Virginia make a hard, long lasting, black slate
  • Glendyne quarry is a few hours north of Quebec which produces a very workable black slate
  • Spain is the worldwide leader of production, and creates a thinner, black slate
  • The NSA has published this bulletin on historical slate production

• Slate the Material
  • Sizing – Bigger sizes are harder to produce because of what specific stone yields. Most slaters want bigger sizes because of a quicker install.
  • Lead Times – If you need a certain thickness or size, and it’s not in stock, you’ll encounter a lead time. This can range from days to weeks. The advice is to prepare for this possibility.
  • Weight – Not all the building projects are suited for the weight of slate as a material. Synthetic has used this as a competitive advantage.
  • Colors – The Slate Valley is one of the only areas in the world that produces colored slates. Due to the limited quantity, you can expect longer lead times and to pay a premium for varying colors.
• Competition
  • Synthetic – Hijacking the premium name “slate” is not a mistake. Slate is stone, not plastic. Most homeowners will not make this distinction. They’ll be conned into thinking their plastic “slate” roof is a long lasting/cheaper alternative than the natural alternative. Synthetics marketing/influencing dollars are hard to resist. There is no substitute for slate.
  • Shingles – When an inexperienced slate contractor encounters a damaged slate roof, it’s commonplace they recommend replacing with shingles to an unsuspecting homeowner. This practice continues to reduce slate on roofs and will eventually lead to a sustained decline in the material. It’s a quick buck for the contractor and one less slate roof.
  • The video below is a perfect example of a roofer who is gearing to synthetic. Lighter, faster install, even a “better product”. He’s not considering the longevity of the product. Will it curl? Will it weather with discoloration? Will the manufacturer be around until the warranty ends? Yet, you’ll get many comments like “If you can’t tell the difference from ground, it’s not worth spending 2x – 3x on it.”

• Price – Slate is an expensive material at first glance. However, the price of material is in line with competing products like synthetic and tile, but each piece must be individually installed, thus labor costs are on the higher side. Price can be a deterrent to the thrifty consumer. They don’t realize it’s less expensive to install the roof once during their lifetime for a bit more cost…than once every 10-20 years.
• Preservation – Many historical societies and communities go out of their way to maintain the history of slate on their homes. This keeps home values high. The uneducated can be persuaded that synthetic slate is a perfectly -“un”- natural substitute. It’s important historical societies understand the history of slate, the craftsmanship, the regal nature, and prestige that having a slate roof promotes. Education is key.
• Architects & Design Professionals
  • What compels them to choose synthetic? A prior bad experience? Too costly? Being uneducated on the material? Not aware it’s still available? Marketing dollars that have convinced them? The more design professionals who spec slate, the better our future will be with regard to our country’s history and building stature. NSA Slate Spec Guide

How to Boost the Industry?

Which issue to address first? Training contractors? Producing more stone from the ground at a workable price point? Convince design professionals to specify more slate? Explaining to historical societies that they should keep slate on homes? Marketing the material to the next generation through social media?

There’s a lot of work to be done. The people in the industry know the product works based on centuries of evidence. We know there is no substitute. We know that owners of slate roofs have superior protection on their home or building that will be passed on to the next generation. It’s a roof of achievement and longevity. My friends laugh at me when I point out all the slate roofs I encounter. Once you know, you know.

The material only goes as far the people who want to work with it. Until they watch the stone being quarried, understanding what the people who are involved in the production go through, knowing the grit of the installers, and what it takes to install a roof piece by piece, it’s just another roofing material. To the insiders, they see the natural beauty combined with craftsmanship to produce art. It’s a true accomplishment.

Email any comments to improve what you’re seeing out there to [email protected]