Metal Roofing Products

Interlock® Metal Slate Roofing: Lifetime Aluminum, Low-Maintenance

Interlock's aluminum slate replicates the elegance of quarried slate at a fraction of the weight — backed by a Lifetime Transferable Warranty.

Transform your home with the timeless sophistication of slate — without the weight, cracking, or cost. Interlock Metal Slate Roofing is engineered to last the lifetime of your home.

Get Your Free Quote
Download Spec Sheet
  • Home
  • |
  • Metal Slate Roofing | UL 2218 Class 4 Hail · Lifetime Warranty | Interlock Roofing
TL;DR Summary
Interlock® Metal Slate Roofing is a premium aluminum panel system engineered to replicate quarried natural slate at 7× lighter weight and zero structural reinforcement. The 0.019″ 3105-H24 panel (17⅝” × 9″ face) weighs ~41 lbs per square, carries UL 2218 Class 4 hail, ASTM E108 Class A fire (assembly), 120 mph warranted wind, AAMA 2605 Alunar® PVDF coating, ICC-ES ESR-1790, FL7263-R7, and CCMC 10475-R.
Overview

What Is Metal Slate Roofing?

Interlock® Metal Slate Roofing delivers the appearance of quarried natural slate in a 0.019" 3105-H24 aluminum panel at approximately 41 lbs per square — eliminating the structural demands of genuine slate at 800–1,500 lbs per square and the two to three replacement cycles asphalt roofs require over 50 years. Finished with the Alunar® Coating System, rated Class 4 under UL 2218, and warranted to 120 mph wind resistance, the system carries ICC-ES ESR-1790, Florida Product Approval FL7263, and CCMC 10475-R — backed by the Guardian Lifetime Limited Non-Prorated Material Warranty.

For total cost of ownership, one installation eliminates the $15,000–$25,000 re-roofing cost that recurs twice within a typical 50-year asphalt ownership window. The 17⅝" × 9" panel installs on slopes of 3:12 or greater with ice and water protection, with color-matched aluminum trim completing every transition — no field-fabricated flashing required. Cool Roof rated by both CRRC and ORNL, it actively reduces peak cooling loads in warm climates. For homeowners in hail corridors, wildfire zones, or coastal wind environments, no competing product delivers an equivalent performance specification.

The transferable Guardian Warranty adds documentable resale value at point of sale. In markets where Class 4 impact ratings qualify for insurance premium reductions, financial returns compound annually across the warranty period. Each installation eliminates two to three asphalt cycles from North America's estimated 11-million-ton annual roofing landfill stream — while the aluminum substrate remains 100% recyclable at end of service life. For homeowners making a permanent roofing decision, Interlock Metal Slate is the convergence of architectural authenticity, engineering rigor, and lifetime financial logic — the last roof any building will ever need.

Table of Contents

Who It's For

Metal Slate Roofing for Every Professional

You want a roof that looks stunning, lasts decades, and never needs painting, re-granulating, or emergency repairs. Interlock Metal Slate delivers all three. The nine-colour collection coordinates with any exterior palette, and the Lifetime Transferable Warranty protects your investment and adds measurable value at resale. Unlike asphalt shingles, Interlock panels will not blow off in high winds, curl in heat, or crack in freeze-thaw cycles. One installation, lifetime performance.

Interlock Metal Slate is specified under CSI MasterFormat Section 07 31 16 (Metal Shingles). The 0.019-inch aluminum alloy 3105-H24 panel (ASTM B209) installs at approximately 40–50 lbs per square, eliminating the structural reinforcement requirements common with slate and clay alternatives. The Alunar® 5-layer fluorocarbon coating system delivers PVDF-based color retention rated to ASTM D-4214-07 (chalk resistance) and ASTM D-2244-16 (color retention). Cool Roof performance is confirmed by CRRC and ORNL testing. Panel dimensions: 17⅝" × 9" face. ICC-ES Evaluation Report ESR-1790 and Florida Product Approval FL7263-R7 (NON-HVHZ) validate performance in applicable jurisdictions. Minimum slope: 3:12 with ice-and-water underlayment; 5:12 with standard underlayment. Class A fire rating available per ESR-1790 §4.4 when installed with GAF Versashield per ESR-2053. UL 2218 Class 4 hail impact. Wind warranted to 120 mph under the Guardian Lifetime Limited Non-Prorated Warranty. 30-year coating warranty. One-time transferable.

Interlock's four-way interlocking installation system is engineered for efficient, repeatable installation by trained professionals. Each panel clicks into adjacent panels horizontally and vertically, creating a watertight system without exposed fasteners. Certified Interlock installers receive training, technical support, and access to the Interlock dealer network. Individual panel replacement is possible without disturbing surrounding panels, simplifying warranty service. Contact your regional Interlock representative to discuss dealer opportunities.

KEY ADVANTAGES

The Interlock Metal Slate Advantage

Lifetime Transferable Warranty

Every Interlock Metal Slate installation is backed by a Lifetime Transferable Warranty — the strongest warranty in the roofing industry. Coverage can be transferred one time to the next owner (a $300 transfer fee applies), protecting your home’s resale value.
Explore now >

Class 4 Impact Resistance

Interlock Metal Slate achieves the highest UL 2218 impact rating — Class 4 — verified by the standard’s 2-inch steel-ball impact drop test. Many insurance providers offer premium discounts for Class 4 rated roofing systems.
Explore now >

Class A Fire Resistance available

Class A fire rating available under ASTM E108 — the highest fire resistance classification, subject to proper underlayment and installation. Interlock Metal Slate provides superior fire protection compared to asphalt shingles and untreated wood shake.
Explore now >

120 MPH Wind Resistance

Interlock’s concealed clip-fastening system locks every panel to the roof deck and to the panels around it, with no exposed fasteners that can loosen or back out over time. The system is warranted against wind uplift to 120 mph and tested to ASTM D3161 Class F, while the interlocking design lets panels expand and contract with temperature swings without breaking the weather seal — so the roof is built to stay secure through the high winds and seasonal storms common across North American climates.
Explore now >

Energy-Efficient Design

Interlock aluminum panels reflect solar energy and release absorbed heat rapidly after sunset, reducing attic temperatures and HVAC cooling loads compared to dark asphalt shingles. The result is lower energy bills and improved home comfort year-round.
Explore now >

Low Lifetime Maintenance

No painting, re-granulating, sealing, or re-nailing — ever. Interlock Metal Slate requires only occasional rinsing to remove debris. Eliminate the recurring cost and disruption of asphalt shingle maintenance from your budget permanently.
Explore now >
AAMA 2605 Certified Coating System

The Alunar® Coating System — Built for Lifetime Color

Every Interlock Metal Slate panel is factory-finished with the proprietary Alunar® Coating System — a 5-stage molecular bonding process engineered to the most demanding performance standards for architectural coatings in North America. At its core, Alunar uses a 70% polyvinylidene fluoride (PVDF) fluoropolymer resin system — the same chemistry trusted by monumental and commercial building projects across the continent. Unlike painted steel or granule-coated asphalt products, PVDF fluoropolymer chemistry does not fade, chalk, peel, or blister. Color stability is independently verified to ASTM D-4214-07 (chalk resistance) and ASTM D-2244-16 (color retention) — requiring less than 5 Delta E units of color change after a decade of continuous UV exposure. Your roof’s color is not applied to the surface — it is bonded into it. That is the difference between a finish that lasts 20 years and one that lasts a lifetime.

Layer 1 — Alunar® Coating System (PVDF Top Coat)

The outermost layer is Interlock’s proprietary Alunar fluoropolymer finish — formulated with 70% polyvinylidene fluoride (PVDF) resin and independently verified to ASTM D-4214-07 for chalk resistance and ASTM D-2244-16 for color retention. This layer delivers color stability confirmed to less than 5 Delta E color change after ten years of continuous UV exposure. It is the permanent face of your roof.
A precision-applied primer layer bonds directly to the treated aluminum surface, creating the adhesion foundation that locks every subsequent layer in place. This primer is the structural bridge between the metal substrate and the PVDF color system — without it, no coating chemistry performs to specification.
A chemical conversion treatment restructures the aluminum surface at the molecular level — transforming it from a passive metal into an active bonding substrate. This layer is critical to corrosion resistance and long-term coating adhesion, and is what separates an architectural-grade finish from a standard painted surface.
Before any coating is applied, each aluminum panel undergoes a multi-stage alkaline cleaning process that removes surface oxides, mill oils, and microscopic contaminants. This step is non-negotiable — surface cleanliness at this stage directly determines the lifespan of every layer above it.
The structural foundation of every Interlock Metal Slate panel — 3105-H24 aluminum alloy, selected for its superior formability, corrosion resistance, and long-term dimensional stability. At approximately 40–50 lbs per square, it is seven times lighter than natural slate and requires no structural reinforcement on standard roof framing.
An applied protective coating on the underside of every panel guards against moisture infiltration, condensation, and galvanic corrosion from below. Most roofing products leave the back face uncoated. Interlock does not — because a lifetime warranty requires protection on all six sides of the panel.
Technical Data

Product Specifications

Specification Details
Base Material & Alloy Specification Aluminum alloy 3105-H24 per ASTM B209
Panel Gauge & Nominal Base Thickness 0.019" (0.483 mm) nominal base thickness
Installed Weight Per Square Approx. 41 lbs per 100 sq ft (0.41 psf installed)
Hail Impact Resistance Rating Class 4 — UL 2218
Fire Resistance Rating Class A fire rating available (requires GAF Versashield Fire-Resistant Roof Deck Protection per ICC-ES ESR-2053; self-adhered underlayment = non-classified assembly)
Wind Speed Resistance — Manufacturer Warranted 120 mph (193 kph) — warranted per manufacturer's installation procedures
Surface Coating System & Finish Warranty Alunar® Coating System — 5-layer fluorocarbon finish; 30-year coating warranty (no chalk >8 ASTM D-4214-07; no color change >5 ΔE ASTM D-2244-16)
Panel Size, Weather Exposure & Coverage Geometry 17⅝" wide × 9" weather exposure per course
Material Warranty Program Name Guardian Lifetime Limited Material Warranty — one-time transferable
Warranty Duration, Ownership Terms & Transferability Lifetime for original registered owner (individual); 50 years from Substantial Completion for organizations or upon transfer to 2nd owner ($300 transfer fee)
Recycled Content & End-of-Life Recyclability Aluminum is 100% recyclable at end of life
Cool Roof Energy Rating & Third-Party Certification Cool Roof rated — CRRC (Cool Roof Rating Council) and ORNL (Oak Ridge National Laboratories) tested
CSI MasterFormat Division & Section Reference 07 31 16 — Metal Shingles
Available Colors

Color Options

Interlock Metal Slate is available in eight architect-curated colors in heavy gauge aluminum — each permanently bonded through the Alunar® PVDF fluoropolymer coating system, engineered to meet ASTM D-4214-07 chalk resistance (numerical rating no worse than 8) and ASTM D-2244-16 color retention (color change no greater than 5 Hunter ΔE units). Unlike paint-over-steel or granule-coated products that fade, chalk, or shed over time, Alunar’s 70% PVDF resin chemistry is backed by a 30-year color warranty — guaranteeing these thresholds are measured, testable, and warranted performance commitments, not marketing language. For projects demanding the ultimate in material authenticity, Interlock Metal Slate is also available in solid copper — a ninth material option in a class entirely its own. Supplied in 16 oz or 20 oz gauge architectural copper, each panel arrives uncoated by design: copper requires no Alunar system and carries no applied finish. Instead, the surface develops a natural living patina — progressing from the initial bright copper tone through warm reddish-browns before settling into the distinctive blue-green verdigris that defines landmark copper architecture worldwide. The transition takes decades, and no two installations age identically. Solid copper Interlock Metal Slate is expected to outlast the structure it protects, with a service life measured in generations rather than years. Whether you select a factory-finished Alunar aluminum color or the timeless character of solid copper, every panel is backed by Interlock’s Lifetime Transferable Warranty. Contact your local Interlock dealer to request a physical color sample and full specification sheet.
Solid Copper
Copper Penny
Hunter Green
Black
Deep Charcoal
Musket Grey
Tile Red
Colonial Brown
Tudor Brown
Material Comparison

Metal Slate vs. Asphalt vs. Natural Slate

How does Interlock Metal Slate compare to traditional roofing materials? The numbers tell a clear story about lifetime value, performance, and total cost of ownership.
Specification Interlock Metal Slate Asphalt Shingles Natural Quarried Slate
Lifespan Lifetime (50+ years) 15-25 years 75-150 years (prone to breakage)
Weight 40-50 lbs/square 250-350 lbs/square 800-1,500 lbs/square
Fire Rating Class A Class A (with mat) Class A (non-combustible)
Warranty Lifetime Transferable 20-30 year limited No manufacturer warranty
Maintenance Low maintenance Periodic inspection, re-nailing Regular inspection, individual tile replacement
Environmental Performance

Sustainability & Energy Efficiency

Interlock Metal Slate is manufactured from aluminum — one of the most sustainable structural building materials available. Aluminum is 100% recyclable at end of life with no degradation in material quality, and Interlock panels contain a high percentage of post-industrial recycled content. Its permanent service life eliminates the repeated manufacturing, transport, and landfill cycles embedded in conventional roofing replacement. Cool Roof certification from CRRC and ORNL confirms measurable energy performance contributions. For homeowners, architects, and sustainability-focused developers, Interlock Metal Slate delivers documented lifecycle environmental performance.
  • High recycled aluminum content in every panel
  • Reflects solar radiation — reduces cooling loads vs. dark asphalt
  • 100% recyclable at end of life — zero landfill waste
Aluminum Coils
Interlock Metal Slate may contribute to LEED v4 credits under Materials & Resources (MR) — Recycled Content, and Energy & Atmosphere — Enhanced Energy Performance. Contact your Interlock dealer for LEED documentation support.
Verified Customer Reviews

What Homeowners Say About Interlock Metal Roofing

This is the 3rd roof I have had put on by Interlock Roofing. I put one on my original house, my cottage, and now my new house. They have always done an excellent job, and the aluminum shingles are a great product — light, sturdy, and good-looking, even years down the road.
Bruce M.Wakefield, MA
Google Symbol
We had our roof replaced in 2017 with an aluminum roof by Interlock Metal Roofing. We live on the lake, and prior to the replacement, we were spending thousands of dollars every year as the shingles used to fly away in the wind. We have never had any problems in the last 9 years. We had a great experience with Interlock Metal Roofing. They were very professional and did a beautiful job, although it was difficult as our roof is quite high. Our roof is still beautiful, and we have never had a worry about it.
Beena M.Sudbury, ON
Google Symbol
I LOVE MY INTERLOCK ROOF! No more climbing up there to clean it off, no more gritty stuff falling into my garden after a few years. It looks fabulous and does what it's supposed to! And then there are the installers: knowledgeable, attentive to detail, and personable. Ivan is a gem! He attended to the addition of a small bit of flashing efficiently and cleaned the whole roof with a blower in short order. After almost ten years, it's STILL the only roof I would choose!
Sue Lyn T.Corvallis, OR
Google Symbol
FAQ

Metal Slate Roofing — Frequently Asked Questions

How long does metal slate roofing last?

Interlock Metal Slate is backed by a Lifetime Transferable Warranty, designed to last the full lifetime of the structure it covers. Unlike natural slate, which can crack and delaminate, or asphalt shingles that require replacement every 15-25 years, Interlock aluminum panels resist impact, corrosion, and freeze-thaw cycling without degrading.
Interlock Metal Slate carries a higher upfront cost than asphalt shingles, but eliminates 2-4 replacement cycles over the same timeframe. When comparing total cost of ownership over 50 years — including materials, labour, and disposal — most homeowners find that Interlock is cost-competitive or less expensive than repeated asphalt replacements.
Yes — and in several ways it exceeds natural slate. Interlock Metal Slate achieves Class 4 impact resistance (UL 2218), verified by the standard’s 2-inch steel-ball impact test. Natural slate cracks under impact and requires frequent individual tile replacement. Interlock aluminum panels will not crack, chip, or delaminate.
Interlock aluminum slate panels are precision-engineered to replicate the shadow depth, surface texture, and dimensional variation of quarried slate. The Alunar coating system applies a multi-layer stone-texture finish that maintains its appearance without painting or sealing. Most observers cannot distinguish Interlock Metal Slate from natural slate at normal viewing distances.
Interlock Metal Slate weighs approximately 40-50 lbs per square (100 sq ft). Natural slate weighs 800-1,500 lbs per square. This dramatic weight difference means Interlock can be installed on virtually any standard residential roof structure with no structural reinforcement required, saving thousands in engineering and construction costs.
In many cases, yes — Interlock aluminum roofing can be installed over existing asphalt shingles without full tear-off, depending on local building codes, deck condition, and current roof layer count. Your authorized Interlock installer will conduct a decking inspection to confirm eligibility. Installing over existing roofing eliminates tear-off labor and disposal costs, reducing overall project expense. Where tear-off is required — due to soft decking, rot, or code restrictions on roof layers — Interlock installers manage the full removal process. Either way, the result is a permanent roofing system that will never need to be removed or replaced.
Yes — in many regions, Interlock aluminum roofing’s UL 2218 Class 4 hail impact rating and 120 mph warranted wind resistance qualify homeowners for significant insurance premium reductions. Discount amounts vary by insurance carrier and jurisdiction, but Class 4 impact-rated roofing consistently triggers meaningful savings in hail-prone markets across North America. Contact your insurance provider to confirm available discounts before installation. Many homeowners find that insurance savings offset a meaningful portion of the installation cost premium within the first 10–15 years of ownership.
Interlock Metal Slate Roofing is available in nine standard colors: Solid Copper, Copper Penny, Hunter Green, Black, Deep Charcoal, Musket Grey, Tile Red, Colonial Brown, and Tudor Brown. All colors are finished with the Alunar® 5-layer fluorocarbon coating system, providing PVDF-grade color stability backed by a 30-year coating warranty per ASTM D-4214-07 and ASTM D-2244-16. Colors complement a full range of architectural styles and exterior palettes. Contact your authorized Interlock installer or visit the Interlock color selector to view samples in your regional lighting conditions before finalizing your selection.
Yes. Interlock Metal Slate panels are available in a Class A fire-rated assembly — the highest rating achievable under UL and ICC standards. Class A requires installation with GAF Versashield fire-resistant underlayment per ICC-ES Evaluation Report ESR-2053, in combination with the Interlock panel system per ESR-1790. Note: installation with self-adhered underlayment results in a non-classified fire assembly. Specify GAF Versashield when Class A fire rating is required by code or insurance. Confirm your underlayment specification with your authorized installer before project commencement.
Yes. The Guardian Lifetime Limited Non-Prorated Material Warranty is transferable once to a subsequent owner. Original individual owners hold a lifetime warranty; organizations and subsequent individual owners hold a 50-year non-prorated warranty. A transfer fee of $300 applies, and transfer must be registered with Interlock Roofing within the required notification period. A documented Interlock roofing system with an active warranty adds measurable, verifiable value in real estate transactions. Contact Interlock Roofing directly to initiate the transfer process.
AT A GLANCE

Key Takeaways

• Replicates the appearance of quarried natural slate (800–1,500 lbs/sq) at ~41 lbs per square — eliminates structural reinforcement requirement.
• 0.019″ (0.483 mm) aluminum alloy 3105-H24 per ASTM B209.
• Panel face: 17⅝” × 9″ with 9″ weather exposure per course.
• UL 2218 Class 4 hail (highest impact class); Class A fire assembly available with GAF Versashield per ESR-2053.
• AAMA 2605 Alunar® PVDF coating — 30-year warranty against chalk (>8 per ASTM D-4214) and fade (>5 ΔE per ASTM D-2244).
• Cool Roof rated by CRRC + ORNL; ICC-ES ESR-1790, Florida Product Approval FL7263-R7, CCMC 10475-R.
• Nine color options including Solid Copper variant; Lifetime Transferable Warranty (50 years on transfer, $300 fee).

Sample ID Heading 1 Heading 2
41 LBS / SQ — 7× lighter than natural slate UL 2218 CLASS 4 hail 120 MPH warranted wind LIFETIME transferable warranty
Profiles

Explore Other Interlock Roofing Profiles

Interlock® Metal Cedar Shingle Roofing

Interlock® Metal Cedar Shingle Roofing is an aluminum shingle stamped with authentic cedar wood-grain texture — the warmth of real cedar with none of the rot, splitting, or discoloration. Rust-proof, virtually maintenance-free, Alunar®-coated, and backed by a transferable Lifetime Limited Warranty.

Interlock® Metal Shake Roofing

Interlock® Metal Shake Roofing recreates the deep, hand-split texture of rustic cedar shake in rust-proof aluminum — rugged character for Cape Cod and Craftsman homes without the warping, rot, or fire risk of wood. Alunar®-coated and backed by a transferable Lifetime Limited Warranty.

Interlock® Metal Tile Roofing

Interlock® Metal Tile Roofing brings the elegance of Mediterranean clay tile to homes that can't bear — or pay to reinforce for — real tile's weight. Lightweight, rust-proof aluminum that resists cracking, hail, and fire; Alunar®-coated and backed by a transferable Lifetime Limited Warranty.

Interlock® Metal Standing Seam Roofing

Interlock® Metal Standing Seam Roofing is a mechanical-lock aluminum panel system with clean vertical lines — the signature look of modern and farmhouse architecture. Concealed fasteners, exceptional wind resistance, rust-proof, solar-compatible, and backed by a transferable Lifetime Limited Warranty.

Interlock® Copper Roofing

Interlock® Copper Roofing is the solid-copper tier of Interlock's system, available in all five profiles in 12, 16, and 20 oz copper. A living material, it weathers from bright metallic through bronze to a distinctive verdigris patina — copper's timeless prestige for luxury and heritage homes, backed by a transferable Lifetime Limited Warranty.

Last modified: May 25, 2026 1:48 pm
Share to...
BufferCopyFlipboardHacker NewsLineLinkedInMastodonMessengerMixPinterestPrintRedditSMSTelegramTumblrVKWhatsAppXingYummly