Interlock® Roofing Systems
Metal Shingles That Look Like Slate or Cedar — and Last for Decades
Interlock metal shingles give you the timeless look of natural slate or cedar in lightweight, rustproof aluminum — engineered for North American weather and backed by a 30-year chalk-and-fade finish warranty.
Metal shingles combine the curb appeal of premium roofing with durability that asphalt simply can't match.
TL;DR Summary
Metal Shingles are individual aluminum roofing panels stamped to replicate the appearance of natural slate or cedar shingle. Interlock metal shingles are formed from 0.019" 3105-H24 aluminum (ASTM B209), weigh ~41 lbs per square, install over standard residential framing without reinforcement, and carry UL 2218 Class 4 hail, 120 mph wind warranty, and a 30-year Alunar® PVDF coating warranty.
Overview
What Are Metal Shingles?
Metal shingles are individual roofing panels — made from metal and stamped to replicate the look of natural materials like slate or cedar shingles. Unlike large standing-seam panels, metal shingles install piece by piece for a textured, dimensional roof, and unlike asphalt, they can last for decades without cracking, curling, or shedding granules.
Interlock metal shingles are made from aluminum — which means they never rust — and come in two shingle profiles: Interlock Slate, with the refined lines of natural slate, and Interlock Cedar Shingle, with the warmth and grain of real cedar. Both interlock across the roof for 120 MPH wind resistance and carry a 30-year chalk-and-fade finish warranty.
Metal Shingles vs. Asphalt: Why Homeowners Make the Switch
Asphalt shingles are replaced every 15 to 25 years; a metal shingle roof is built to last for decades. Homeowners switch for the combination only metal delivers: the premium look of slate or cedar, the durability to shrug off wind and weather, and a finish that stays true instead of streaking and fading.
Table of Contents
- What Are Metal Shingles?
- Metal Roofing for Every Stakeholder
- Why Choose Metal Shingles
- The Alunar® 5-Layer Coating System: Science Behind the Lifetime Color
- Why a 48-Year Metal Roofing Coatings Veteran Endorses Interlock®
- Metal Shingle Specifications
- Metal Roofing Color Collection
- Metal Shingles vs. Asphalt vs. Natural Slate or Cedar
- A More Sustainable Roof
- Metal Roofing in Action: Project Case Studies
- What Homeowners Are Saying About Interlock Metal Roofing
- Metal Shingles: Frequently Asked Questions
- Key Takeaways
Who It's For
Metal Roofing for Every Stakeholder
If you've replaced an asphalt roof once, you already understand the pain: disruption, cost, landfill waste, and the nagging knowledge that you'll do it all again in 15 years. Interlock aluminum metal roofing ends that cycle permanently. Our Guardian Lifetime Transferable Warranty means your investment is protected for the life of your home — and can be transferred one time to the next owner (a $300 transfer fee applies), making it a genuine selling advantage when you list. With Class 4 hail protection, Class A fire resistance, and wind uplift resistance to 120 mph, Interlock is built for the climate reality of the 2020s and beyond.
See Profiles & Colors →Interlock Metal Roofing carries ICC-ES ESR-1790 — a code-compliance evaluation report that simplifies municipal permit approval in virtually every North American jurisdiction. Profiles are available in both aluminum and copper, enabling material continuity across low-slope accents, vertical cladding, and primary roof plane. Alunar® PVDF coatings comply with AAMA 2605, with spectral reflectance data available for energy modeling under ASHRAE 90.1. Full DWG/PDF technical drawings, cut sheets, and CSI MasterFormat specifications (Section 07 61 00) are available through the Interlock Architect Resource Center.
Download Architect Specs →Interlock metal roofing panels are engineered for efficient installation on slopes of 3:12 or greater with ½" minimum sheathing and synthetic underlayment. The integrated clip-fastening system eliminates exposed fasteners and accommodates thermal expansion across all climate zones without field modification. A complete color-matched trim suite — ridge caps, hip caps, rakes, eaves, valleys, and step flashings — requires no field-fabricated flashing at any transition. Installation training and dealer certification is available through Interlock's North American dealer network.
Contractor Resources →Key Advantages
Why Choose Metal Shingles
The Strength of Metal, the Look of Slate or Cedar
Metal shingles give you the high-end appearance of natural slate or cedar without the cracking, rot, or upkeep. Interlock stamps that detail into aluminum, so the roof looks like the real thing and performs far longer.
Explore now >Built to Last Three to Four Times Longer Than Asphalt
Where asphalt is replaced every couple of decades, a metal shingle roof is a once-in-a-lifetime install. You stop paying for repeat tear-offs and reroofs.
Explore now >Lightweight — Often Installs Over Your Existing Roof
At roughly 0.4 lbs per square foot (about 41 lbs per 100 sq ft), metal shingles weigh far less than slate or tile and can often be installed directly over an existing roof, saving tear-off cost and landfill waste.
Explore now >Engineered for Wind, Rain, and Snow
Interlock's panels lock together across the entire roof plane for 120 MPH wind resistance, and shed the rain and snow load that wears asphalt down.
Explore now >A Finish That Won't Fade or Streak
The multi-layer Alunar finish resists chalking and fading and is backed by a 30-year warranty, so your roof keeps its color for decades instead of bleaching and streaking like asphalt.
Explore now >Made from Aluminum — So They Never Rust
Interlock metal shingles are aluminum, not steel, so there is no rust — even at cut edges or in coastal and high-humidity climates. They are also made with high recycled aluminum content and are fully recyclable at end of life.
Explore now >AAMA 2605 Certified Coating System
The Alunar® 5-Layer Coating System: Science Behind the Lifetime Color
Every Interlock aluminum metal roofing panel — across every profile and every color — is finished with the proprietary Alunar® coating system. Developed specifically for exterior architectural aluminum, Alunar is a 5-layer factory-applied system that permanently bonds PVDF fluorocarbon resin to the aluminum substrate. The result is a finish that meets AAMA 2605 — the most demanding specification for architectural aluminum coatings — and is warranted against chalk and fade for 30 years.
Layer 1: Aluminum Substrate
Premium aluminum alloy — 0.028" 3000-series for Shake, Mediterranean Tile, and Standing Seam profiles; 0.019" 3105-H24 for Slate and Cedar Shingle profiles. All substrates are corrosion-resistant, 100% recyclable, and galvanically compatible with all standard roofing metals including copper flashings and copper accent panels.
Layer 2: Chemical Pre-Treatment
A controlled acid-wash and conversion-coat process removes surface oxides and deposits a micro-crystalline conversion layer that maximizes coating adhesion at the molecular level. This critical step is where most coating failures originate — Interlock's factory process never shortcuts it.
Layer 3: Corrosion-Inhibiting Primer
High-build corrosion-inhibiting primer is roller-applied in controlled factory conditions and oven-cured to the substrate. This layer provides the adhesion bridge between metal and topcoat and delivers secondary corrosion resistance even if the topcoat sustains a scratch or edge exposure.
Layer 4: PVDF Topcoat (Alunar® Fluorocarbon)
70% PVDF resin topcoat is applied to a minimum 1.0 mil DFT and oven-cured at controlled temperature. PVDF fluorocarbon is the gold standard of architectural coatings — used on curtain walls, storefronts, and premium roofing worldwide — for its unmatched UV resistance, chalk resistance, and fade resistance. Verified to AAMA 2605.
Layer 5: UV-Transparent Clear Overcoat
A UV-transparent clear coat is applied over the color layer to increase surface hardness, add chalk and fade protection, and extend the effective service life of the topcoat system. The clear coat also enhances color depth and architectural finish quality.
Layer 6: Reverse-Side Wash Coat
The back face of each panel receives a protective wash coat that prevents moisture-driven oxidation from the underside — a common long-term failure mode on lower-quality coated metal panels that lack reverse-face protection.
Industry Expert Testimonial
Why a 48-Year Metal Roofing Coatings Veteran Endorses Interlock®
“In my 48 years of experience in the metal roofing industry (21 years with Desoto, 10 years with Morton International, 6 years with BASF and 10 years with 3M), it is most unique to find a company who is constantly striving to provide roofing products that live up to claims that are being made to customers. From the very moment the Interlock Roofing System is applied to a home the customer experiences excellent installation and a very unique surface design all applied to the finest metal available. All these are provided with the promise of great durability and sustainability and a low maintenance roofing system. The use of Alunar(r) Coating Systems, which have a superior record of color fastness, chalk resistance and literal fusion like adhesion is the finest coating system anyone can provide.”
Robert Scichili
Robert Scichili Associates, Inc.
Independent testimonial from an industry expert. Robert Scichili is President of Robert Scichili Associates, Inc. (Richardson, TX) and Principal Partner at RSK Avanti Partners LLC — a strategic marketing, sales, and technical development consultancy for the metal construction and architectural coatings industries. He previously served as Business Development Manager for the Industrial Coatings Division at BASF Corporation, where he led market positioning for the Ultra-Cool reflective coatings line. Robert is a founding Board Member of the Cool Metal Roofing Coalition and a published authority on Energy Star, LEED, and cool metal roofing technologies. His 48-year career in industrial coatings spans Desoto, Morton International, BASF, and 3M.
Robert Scichili · President, Robert Scichili Associates, Inc. · 21 years Desoto · 10 years Morton International · 6 years BASF · 10 years 3M
Technical Data
Metal Shingle Specifications
| Specification | Details |
|---|---|
| Base Material & Alloy | Aluminum alloy per ASTM B209 — 3105-H24 for Slate and Cedar Shingle; 3003-H24 for Shake, Mediterranean Tile, and Standing Seam |
| Panel Gauge & Base Thickness | 0.019" (0.483 mm) nominal base thickness |
| Installed Weight | Approx. 41 lbs per 100 sq ft (about 0.4 lbs per sq ft installed) — Slate and Cedar Shingle profiles |
| Hail Impact Resistance | Class 4 — UL 2218 (highest impact-resistance class) |
| Fire Resistance | 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 | 120 mph (193 kph) — warranted per manufacturer's installation procedures |
| 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 | 17⅝" wide × 9" weather exposure per course (Slate and Cedar Shingle) |
| Material Warranty Program | Guardian Lifetime Limited Material Warranty — one-time transferable |
| Warranty Duration & 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 & Recyclability | Made with high recycled aluminum content; 100% recyclable at end of life |
| Cool Roof Energy Rating | Cool Roof rated — CRRC (Cool Roof Rating Council) and ORNL (Oak Ridge National Laboratories) tested |
| CSI MasterFormat Reference | 07 31 16 — Metal Shingles |
Available Colors
Metal Roofing Color Collection
Interlock metal roofing is available in a curated palette of low-gloss architectural colors, all finished with the Alunar® PVDF fluorocarbon system. Colors are consistent across all profiles — mix metal shake on the main field with standing seam on dormers, in the same color family, for complete design continuity.
Material Comparison
Metal Shingles vs. Asphalt vs. Natural Slate or Cedar
How metal shingles compare to the alternatives across the factors that matter most over the life of a roof.
| Metal Shingles (Interlock) | Asphalt Shingles | Natural Cedar / Slate | |
|---|---|---|---|
| Typical Lifespan | 50+ years; backed by the Guardian lifetime limited material warranty (50 yrs on transfer) | 15 to 25 years | Cedar 20 to 30 yrs; slate 75+ but very heavy and costly |
| Weight | Very light (~0.4 lbs/sq ft); often installs over existing roof | Moderate; tear-off usually required | Heavy; slate may need structural reinforcement |
| Maintenance | Low; finish backed for 30 years | Algae streaking; periodic replacement | Cedar needs treating; moss and rot; slate can crack |
| Fire | Noncombustible aluminum; Class A fire rating available with the specified underlayment | Combustible | Cedar combustible unless treated; slate noncombustible |
| Look & Lifetime Cost | Slate / cedar look at lower lifetime cost | Basic look; lowest upfront cost | Premium look; highest cost and upkeep |
Real Installations
Interlock Metal Slate Roofing — Project Gallery
Interlock Metal Slate reproduces the timeless profile of natural slate across homes throughout Canada and the United States — without the weight, fragility, or eventual replacement that define traditional stone slate roofing. Manufactured from lightweight aluminum and protected by the Alunar® Coating System — a 70% PVDF formula engineered to resist fading and chalking for a minimum of 30 years — it's available in nine colors including Deep Charcoal, Musket Grey, Colonial Brown, and Hunter Green. Wind-rated to 120 mph and backed by the Guardian Lifetime Limited 50-Year Transferable Warranty, Interlock Metal Slate is a permanent roofing solution built to never be replaced.
Environmental Performance
A More Sustainable Roof
Because Interlock metal shingles are aluminum, they are one of the greenest roofing choices available — built largely from recycled metal, fully recyclable, and durable enough that you reroof far less often.
- High recycled aluminum content in every panel
- 100% recyclable at end of life
- 1 install vs. 3 to 4 asphalt reroofs over the same period
Case Studies
Metal Roofing in Action: Project Case Studies
Historic Victorian Home — Asphalt to Aluminum Slate Conversion
Challenge: The homeowners needed a roof that would replicate the visual character of original quarried slate — important in a heritage neighborhood with strict aesthetic guidelines — while providing modern code-compliant fire resistance and a warranty lasting beyond the next ownership generation.
Solution: Interlock Aluminum Slate panels in Aged Pewter were installed over synthetic underlayment and new OSB sheathing. The complete color-matched trim system required no custom field fabrication at complex hip and valley geometry. Total installation: 3 days for a 28-square application.
Result: Heritage board approval granted. Homeowner insurance reclassified to Class 4 hail, generating a 24% annual premium reduction. Guardian Lifetime Transferable Warranty issued. Estimated lifecycle savings vs. repeated asphalt replacement: $34,000 over 40 years.
New Construction — Premium Coastal Home with Copper Accent Roofing
Challenge: The architect specified copper roofing for front dormers and the entry canopy as a design signature element, with aluminum for the main roof field — requiring material continuity in color tone and full trim compatibility between the two metals.
Solution: Interlock Standing Seam in Weathered Charcoal aluminum on the main field, with Interlock Natural Copper installed on three dormers and the entry canopy. Interlock's aluminum-copper trim compatibility ensured clean transitions with zero galvanic conflict. The copper sections will develop natural patina over 3–5 years, progressively evolving the home's façade.
Result: Full architect specification met. No galvanic incompatibility issues. Copper sections pre-approved for HOA installation. Main field covered by Guardian Lifetime Warranty; copper sections covered by Interlock's copper material warranty.
Customer Reviews
What Homeowners Are Saying About Interlock Metal Roofing
★★★★★After our third hail-damaged asphalt roof in twelve years, our insurance company actually recommended metal roofing. We chose Interlock shake and haven't looked at another hail claim since. The 28% insurance premium discount alone pays for a significant portion of the upgrade — and the roof looks better than anything in the neighborhood.
★★★★★I was replacing the original 1940s slate on our heritage-designated home and needed something that would satisfy the heritage board visually while meeting current fire codes. Interlock aluminum slate was the only product that cleared both hurdles. Seven years in, it looks exactly as it did when it was installed.
★★★★★We were primarily motivated by energy costs — our previous dark asphalt roof was cooking the house every summer. The Interlock standing seam in Classic White dropped our cooling load noticeably in the first season. The lifetime warranty and Class 4 hail rating were the bonuses that made it an easy decision.
FAQ
Metal Shingles: Frequently Asked Questions
Common questions about metal shingle roofing, answered.
What are metal shingles?
Metal shingles are individual metal roofing panels stamped to look like slate or cedar shingles. They install piece by piece for a dimensional look and, unlike asphalt, can last for decades without cracking, curling, or losing granules.
How long do metal shingles last?
Metal shingle roofs are commonly expected to last 50 years or more — far longer than the 15 to 25 years typical of asphalt. Interlock's finish carries a 30-year chalk-and-fade coating warranty, and the panel itself is covered by the Guardian Lifetime Limited Material Warranty (lifetime for the original registered owner; 50 years when transferred).
Are metal shingles better than asphalt?
For longevity and durability, yes — metal shingles last far longer, won't curl or lose granules, and stand up better to wind and fire. Asphalt costs less up front, but metal usually costs less over the life of the home because you install once instead of reroofing repeatedly.
How much do metal shingles cost?
Metal shingles cost more up front than asphalt but often less over time, because you typically install once instead of reroofing every couple of decades. Price depends on the profile, roof size and complexity, your region, and whether you install over an existing roof. A free quote is the most accurate way to know.
Are metal shingles noisy when it rains?
No. Installed over solid roof decking (and often over an existing roof) with underlayment, a metal shingle roof is about as quiet as asphalt. The 'loud metal roof' idea comes from bare, barn-style panels on open framing, which is a different product entirely.
Do metal shingles attract lightning?
No. Metal roofs do not attract lightning. And because metal is noncombustible, a metal roof is actually a safer material than wood or asphalt if lightning ever does strike nearby.
Can metal shingles be installed over an existing roof?
Often, yes. Because metal shingles are lightweight, they can frequently be installed over an existing layer of shingles, which avoids tear-off labor, cost, and landfill waste. A roofing professional should confirm your roof's condition first.
What are Interlock metal shingles made of?
Aluminum. Interlock's metal shingles are aluminum rather than steel, so they never rust — even in coastal and high-humidity climates. They are offered in two profiles: Interlock Slate and Interlock Cedar Shingle.
What do metal shingles look like?
Interlock metal shingles replicate premium natural roofing: Interlock Slate captures the clean lines of natural slate, and Interlock Cedar Shingle captures the grain and warmth of real cedar — both available in a range of colors. From the ground, they look like the real material, without the cracking, moss, or fading.
Are metal shingles a good investment?
Metal shingles offer a long service life, a Class 4 (UL 2218) hail impact rating, and Cool Roof–rated energy efficiency, and they spare you repeated asphalt reroofs. Many homeowners also value the severe-weather durability; some regions offer insurance considerations for impact-resistant roofs, so it's worth checking locally.
At a Glance
Key Takeaways
- Two shingle-profile options: Interlock Slate (refined natural-slate lines) and Interlock Cedar Shingle (real cedar grain and warmth).
- 0.019" (0.483 mm) aluminum alloy 3105-H24 substrate per ASTM B209.
- Approximately 41 lbs per 100 sq ft (~0.4 lbs/sq ft) — often installs over existing asphalt without tear-off.
- Panel face 17⅝" × 9" with 9" weather exposure per course.
- UL 2218 Class 4 (highest impact class) and Class A fire-rated assembly available (with GAF Versashield per ESR-2053).
- Cool Roof rated by CRRC + ORNL — reflects solar radiation to reduce summer cooling loads.
- CSI MasterFormat 07 31 16 (Metal Shingles); ICC-ES ESR-1790, FL7263-R7, CCMC 10475-R.
| 41 LBS / SQ (~0.4 lbs/sq ft installed) | 120 MPH wind warranted | UL 2218 CLASS 4 hail | 30-YEAR Alunar® coating warranty |
Documentation
Metal Roofing Technical Resources
Explore More
Explore Interlock Metal Shingle Profiles
Interlock® Metal Slate Roofing
Interlock® Metal Slate Roofing is a lifetime aluminum system that captures the dimensional beauty of natural slate — ideal for Colonial and Victorian homes — without the weight, cracking, or reinforcement costs of stone. Rust-proof, Alunar®-coated for energy savings, and backed by a transferable Lifetime Limited Warranty.
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.
Get Started
Free, No-Obligation Interlock® Consultation
Every Interlock® consultation is free and carries no obligation — for homeowners, architects, and roofing contractors alike. Contact Interlock and a certified local sales representative from your exclusive Interlock® dealer will reach out to schedule a Zoom call, office meeting, or in-home consultation. The conversation walks through profile selection, technical installation requirements (slope, venting, underlayment, fasteners, trim, snow management, solar), and project-specific pricing — in that order, never the reverse.
For homeowners →
Review profile options, color samples, and the Guardian Lifetime Transferable Warranty applied to your specific home.
For architects →
Walk through CSI MasterFormat 07 31 16 / 07 41 13 specifications, ICC-ES ESR-1790 documentation, and assembly options for your project submittal.
For roofing contractors →
Discuss certified-installer territory, training, technical support, and warranty registration through the Interlock® dealer network.
Prefer to talk? 1-866-733-5811
Request Your Free Quote
A specialist will match you with your local certified Interlock® installer.