Architect & Specifier Resources
CSI specifications, ASTM standards, LEED documentation, and technical data for natural slate roofing systems.
Writing Slate Roofing Specifications
Natural slate roofing is specified under CSI MasterFormat Section 07 31 13 — Slate Roofing. This section covers all aspects of slate tile procurement, installation, and quality assurance for architectural projects.
A complete slate roofing specification should include the following key sections:
- Scope of Work: Define the extent of slate roofing, including areas, slopes, and any special conditions such as dormers, valleys, or chimneys.
- Submittals: Require product data sheets, ASTM test reports, color samples (minimum 3 representative pieces), and installer qualifications.
- Quality Assurance: Specify installer experience (minimum 5 years with natural slate), manufacturer's technical representative availability, and mock-up requirements.
- Materials: Reference ASTM C406 Grade S1, minimum 3/16" thickness, copper or stainless-steel fasteners, and copper flashings at all penetrations.
- Execution: Address installation per NRCA guidelines, weather conditions, protection of completed work, and inspection requirements.
Performance Requirements: Specify ASTM C406 Grade S1 (the highest grade), minimum 3/16" (4.8mm) thickness for standard applications, and copper fasteners throughout. These requirements ensure a roof system with a service life exceeding 100 years.
ASTM Standards for Natural Slate
Natural slate roofing is governed by a suite of ASTM International standards. Understanding these standards is essential for writing accurate specifications and evaluating product submittals.
| Standard | Scope | Key Requirements | Newmont Compliance |
|---|---|---|---|
| ASTM C406 | Standard Specification for Roofing Slate — the primary procurement standard | Grade S1: ≥75 yr service life; Grade S2: 40–75 yr; Grade S3: 20–40 yr | Grade S1 certified; test reports available |
| ASTM C120 | Test Method for Flexure Testing of Slate | Minimum modulus of rupture across and along the grain | Tested per standard; results in product data sheet |
| ASTM C121 | Test Method for Water Absorption of Slate | Maximum water absorption by weight after 48-hour immersion | Vermont slate typically <0.25% — well below limits |
| ASTM C217 | Test Method for Weather Resistance of Slate | Acid resistance test simulating long-term weathering | Excellent resistance; full test data available on request |
When referencing these standards in project specifications, cite the standard number and year of the most current edition (e.g., "ASTM C406, current edition"). Require the contractor to submit test reports from an accredited laboratory confirming compliance prior to material delivery.
For projects requiring enhanced documentation, Newmont can provide certified test reports, mill certificates, and quarry-of-origin documentation to satisfy owner or agency requirements.
LEED & Sustainability Credits
Natural Vermont slate supports multiple LEED v4 credits and contributes to a project's overall sustainability narrative. As a natural material quarried and processed in Vermont, slate offers a compelling environmental profile.
- MR Credit: Regional Materials — Vermont slate is quarried and processed within the state. For projects within 500 miles of the quarry, slate qualifies for the Regional Materials credit, covering most of the northeastern United States and portions of the mid-Atlantic and Midwest.
- MR Credit: Recycled Content — Slate is a natural material with no manufacturing waste stream. While it does not contain post-consumer recycled content, its extraction process generates minimal waste, and quarry offcuts are often repurposed for other applications.
- IEQ Credit: Low-Emitting Materials — Natural slate contains no VOCs, requires no adhesives, and emits no off-gassing. It fully satisfies low-emitting material requirements for roofing assemblies.
Environmental Profile vs. Synthetic Alternatives: Unlike synthetic roofing products made from petroleum-based polymers or recycled rubber, natural slate requires no chemical processing, no binders, and no coatings. Its service life of 100+ years means far fewer replacement cycles — dramatically reducing lifecycle environmental impact compared to 20–30 year synthetic products.
Technical Details & CAD Resources
Newmont provides a full library of standard installation details for use in construction documents. Details are available in AutoCAD DWG, PDF, and DXF formats. BIM objects (Revit RFA) are available for select products upon request.
Standard details available include:
- Eave Detail: 1.5" overhang beyond fascia, double starter course with staggered joints, copper drip edge flashing.
- Ridge Detail: Saddle ridge with copper cap flashing; combing ridge option also available for traditional profiles.
- Hip Detail: Mitered hip with copper saddle flashing; Boston hip option for historic applications.
- Valley Detail: Open valley with 24"-wide copper liner, minimum 16 oz copper; closed-cut valley option available.
- Chimney Detail: Step flashing with counter-flashing, cricket for chimneys wider than 30"; all copper.
- Dormer Detail: Sidewall flashing, head flashing, and apron flashing — all coordinated with slate coursing.
To request CAD files, BIM objects, or custom details for your project, contact our technical team with the project name, location, and specific detail requirements. Custom details for unusual conditions are available at no charge for specified projects.
Request CAD/BIM Files: Email [email protected] with your project name and required details. Files are typically delivered within 2 business days.
Product Data Sheets & Submittals
Newmont provides a complete submittal package for all specified projects. Our documentation is formatted to meet standard AIA submittal requirements and can be customized to match project-specific submittal schedules.
What Newmont provides:
- Product data sheets for all slate colors and sizes
- ASTM C406 test reports from accredited laboratory
- ASTM C120, C121, and C217 test data
- Physical color samples (minimum 3 representative pieces per color)
- Sample slates in specified size for mock-up approval
- Quarry-of-origin documentation and chain of custody
- LEED documentation package (regional materials, low-emitting materials)
Submittal Requirements: Specifications should require product data, samples (minimum 3 pieces per color showing natural color variation), and ASTM test reports. Submittals should be provided at least 4 weeks before scheduled material delivery to allow adequate review time.
How to Request Submittals
Email [email protected] with: project name, project location, architect of record, required slate colors, and required sizes. Lead times: Product data sheets — immediate; physical samples — 5–7 business days; full submittal package — 7–10 business days.
Working with Newmont's Technical Team
The best outcomes happen when we're engaged early — ideally during design development, before specifications are finalized. Early engagement allows us to tailor product recommendations to your project's aesthetic goals, budget, and performance requirements.
Services we provide at no charge for specified projects:
- Specification Review: We review your Section 07 31 13 draft and provide comments to ensure accuracy and completeness.
- Submittal Preparation: Full submittal packages formatted to your project requirements.
- Contractor Recommendations: We maintain a network of experienced slate roofing contractors throughout the Northeast and can recommend qualified installers for your project location.
- Site Visits: For significant projects, our team can visit the site during design to assess conditions and provide recommendations.
- Mock-Up Support: We provide sample slates and technical guidance for installation mock-ups.
Bob Williams, President
Technical Contact — Newmont Slate Company
Related Technical Guides
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