Early in 2014, the NSA met in Florida to discuss and define who we are and what we stand for. The last time this happened was in 2002, in Saratoga, New York. Before that, in Bomoseen, Vermont, 1922.

Like all the best ideas, the answer was ultimately very simple: to promote slate in North America, and to promote the highest standards of materials and installation.

This Purpose Statement was achieved after much discussion, a dialectic that reflected a deep respect for the tradition and history of slate, while looking to ignite a new fervor for a national heritage that has value and relevance to the future.

The National Slate Association is the place where Quarriers, Suppliers, Consultants and Slaters meet. Technical information is shared, and business connections are made. Camaraderie is found as we celebrate our achievements, but most important of all it is our opportunity to give back to the industry. It is our efforts in this industry that have enabled us to make livings and raise families. Now is our chance to tend to the industry; to ensure it is vibrant and strong for our successors to enjoy; to ensure that standards are kept and raised, that the trade we love is held high and respected in North America.

Visit our website.

UK Slate Conference

The National Slate Association & Slate Roofing Contractors Association recently traveled to the United Kingdom for an immersive slate industry tour and unforgettable experience. The trip included visits to the Admiralty Arch rooftop, Burlington Stone Quarry, the NFRC award show, and sightseeing tours throughout London and Edinburgh. 

Missed out? Read about the experience and make sure you sign up for the next one!

Why Join National Slate Association?

The National Slate Association appreciates the history, beauty, and proven nature of natural slate while dedicating it to the mission of supporting it as a material. Other materials feel wasteful and inferior compared to the longevity and eco-friendly nature of slate. The National Slate Association has come together to promote and educate how to use natural slate as a roofing material. By joining, you’re engaging in a community of like-minded people who respect the centuries-long tradition of slate installation. Learn installation specifics from the brightest minds the industry has to offer or shake hands with suppliers who will keep you competitive in the trade. Be listed in the NSA Member Directory as a qualified business in the industry. These are all benefits of joining this prestigious association.

Learn more about our membership.

UK Slate Trip Report

The NSA Board visited the NFRC show in London, England, Ffestiniog & Penrhyn Quarry in Wales, and historic slate roofs and landmarks in Dublin, Ireland. 

UK Trip Report w/ Pictures

Become NRCA PROCertified®

The NRCA PROCertified® Slate Systems Installer certification verifies the knowledge and skill of an experienced roof systems installer. It is intended for experienced members of the field and helps to keep the workforce to a high standard of competency, sustainability and  performance. This certification can prove your knowledge of industry best practices for roof system installation.

To become NRCA PROCertified, you must meet all eligibility requirements and pass a hands-on performance exam. If you're interested, the NRCA Slate ProCertification Exam has been finalized and is looking for installers to test their skills. Reach out for more information on becoming ProCertified!

Slate colors & characteristics 

Natural slate is a microcrystalline, fine grained metamorphic rock formed 400 million to 550 million years ago, with its beginnings as sedimentary silt washed into ancient seas. These sediments accumulated on the sea floor for 150 million years, forming a bed of clay and shale several thousand feet thick. During later geological upheaval, these sedimentary shale beds were lifted from the ocean floor, folded, and buried on the North American continent. Sediments accumulated on the sea floor were exposed to extreme pressures which lead to the chemical and mineralogical transformations you see today. As a result, the sedimentary bedding plains of the original clay and shale are totally independent of the metamorphic grain of the resultant slate bed. Natural slate has many uses which include roofing material, floor tile, countertops, wall cladding, blackboards, and even tub and shower enclosures.

Weathering designations

The color of a natural slate is derived from its chemical and mineral composition. Chlorite produces green slate, hematite the purples, carbon the grays and blacks, and hematite and iron oxide the reds.

Descriptions of color can vary widely from supplier to supplier, but generally, roofing slate produced in North America falls under the general color descriptions of black, gray/black, gray, green, gray/green, purple, variegated purple, mottled purple/green, and red.

One of the unique and aesthetic advantages of natural roofing slate is the subtle variation in color, shade, veining, and grain of each individual slate shingle on a roof. These color variations should be expected.

Learn more.

Who we serve

• Contractors: Join a community of contractors across the USA that is supports by the National Slate Association!
• Architects: Learn more about how the National Slate Association supports architects across the USA!
• Homeowners: The National Slate Association helps homeowners across the USA maintain their homes quality!

See what we are all about!

The Roman Catholic Church of the Archdiocese of New Orleans, Notre Dame Seminary

Complete roof restoration of Roman Catholic Church of the Archdiocese of New Orleans, Notre Dame Seminary, including 840 sq. slate roof restoration/replacement; custom copper gutters & hangers – 3,000 linear feet; custom copper hip & ridge to match originals – 2,000 linear feet; gypsum deck repairs – 10,000 sq. ft.; new standing seam copper dormer tops to match originals – 26 units; new copper flashings; new custom copper finials to match originals; new 16′ tall copper cupola to match originals; carpentry/paint-work on dormers; clay tile roof repair; and built up roofing systems on flat roofs.

Learn more.

San Francisco Theological Seminary

San Francisco Theological Seminary of Northern California was originally constructed in 1891.

Repairs to the slate roof were required.

View the full project!

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Perspectivas legales clave en la IRE 2025

Por Emma Peterson, traducido por Jessica Bravo. ¡No te pierdas las sesiones educativas del experto en la industria Trent Cotney! ¿Estás listo para la 2025 International Roofing Expo (IRE)? Comenzando el 19 de febrero de 2025 en San Antonio, Texas, este es el evento comercial más grande para la ...
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2026 UK Roofing Awards celebrate excellence across the roofing industry

By Heidi J. Ellsworth. RoofersCoffeeShop.uk joined roofing professionals from across the U.K. to celebrate award-winning craftsmanship, innovation and community. The U.K. roofing industry came together in spectacular fashion at the 2026 U.K. Roofing Awards, recognizing the projects, companies and individuals who continue to raise the bar for excellence across roofing and cladding. ...
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Latest Podcasts

John Chan - Inside the NSA Conference 2024

In this episode of Roofing Road Trips, host Megan Ellsworth chats with John Chan about the highly anticipated National Slate Association Conference taking place from October 24-26, 2024, in Charleston, South Carolina. Get an in-depth look at the agenda, registration details and what attendees can expect from this exciting event. ...
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NSA T-Shirt $25.00 2023 NSA T-Shirt Displays professionalism Vintage design Soft, high fabric, heather t-shirt Available in medium, large, XL and XXL “Don’t Fake It, Slate It” Purchase here.
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Gwilym Roberts led a very successful academic life as Dean of Arts and Humanities at the University of Farmington, Maine. Both his father and two Welsh immigrant grandfathers were slate workers from Brownville, Maine, and this heritage became the subject of his book, New Lives in the Valley. The Valley ...
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David Robinson has been in the residential slate business for more than twenty years. He understands the pitfalls and benefits of buying a home with a slate roof. In this book he provides a wealth of information, clearly explained, to assist homeowners. Jack-leg contractors are exposed, the beauty and longevity ...
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Latest Videos

The Weekly Blend - LIVE From London!

Join us every Friday to learn the latest news in the roofing, metal and coatings industry. The 208th episode of The Weekly Blend is coming to you live from London! Join The Coffee Shops’ President Heidi Ellsworth and Multimedia Manager Megan Ellsworth for the latest episode of this Coffee Shop original ...
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National Slate Association Video Playlist

Learn more about the National Slate Association by visiting their directory. Subscribe to the National Slate Association YouTube channel! Access the NSA Manual here. The Life Cycle of Slate Brian Chalsma talks with Steve Taran about the life cycle and fire resistance of slate. NSA Interviews at 2019 Conference in Washington DC Watch members give their ...
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Episode 39 - Hurricane Relief, Networking Bingo and LIVE Coffee Conversations at METALCON!

Join Heidi and Karen every Friday to hear what they have to say about all the happenings within the roofing industry. The 39th episode of our Weekly Blend series is here! Join President Heidi J. Ellsworth and COO Karen L. Edwards for another exciting installment of this RoofersCoffeeShop® (RCS) original ...
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