Interlock® Roofing Systems
Aluminum Shingles That Never Rust, Crack, or Curl
Get the timeless look of natural cedar shingles or slate in lightweight, corrosion-proof aluminum — engineered for North American weather and backed by a 30-year chalk-and-fade finish warranty.
Interlock aluminum shingles combine the curb appeal of premium roofing with the durability only metal can deliver.
TL;DR Summary
Aluminum Shingles are interlocking metal roofing panels formed from corrosion-resistant aluminum alloy (Interlock: 0.019" 3105-H24 per ASTM B209) and stamped to replicate natural cedar or slate. Because aluminum forms a self-protecting oxide layer rather than rusting, the system performs reliably in coastal, lakeside, and high-humidity climates where steel and asphalt fail early.
Overview
What Are Aluminum Shingles?
Aluminum shingles are interlocking metal roofing panels — stamped and finished to replicate the look of natural cedar shingles or slate — made from corrosion-resistant aluminum instead of asphalt, steel, or stone. Because aluminum does not rust, an aluminum shingle roof can protect a home for decades with minimal maintenance, even in coastal and high-moisture climates.
Interlock aluminum shingles add an interlocking panel design and a multi-layer Alunar finish to that foundation. The interlocking panels lock together across the entire roof for 120 MPH wind resistance, while the Alunar finish is backed by a 30-year chalk-and-fade warranty so the color stays true for the life of the roof.
Why Homeowners Are Switching to Aluminum
Asphalt shingles get replaced every 15 to 25 years; aluminum is a once-in-a-lifetime roof. Homeowners choose aluminum shingles for three reasons: they never rust, they shrug off wind and weather, and they deliver the high-end look of natural cedar or slate without the weight, upkeep, or fire risk of the real thing.
Table of Contents
- What Are Aluminum Shingles?
- Interlock® Aluminum Metal Roofing for Every Audience
- Why Choose Aluminum Shingles
- The Alunar® Coating System — Built for Lifetime Color
- Why a 48-Year Metal Roofing Coatings Veteran Endorses Interlock®
- Aluminum Shingle Specifications
- The Interlock® Aluminum Color Palette
- Aluminum Shingles vs. Steel vs. Asphalt
- A More Sustainable Roof
- Metal Slate Roofing — Project Case Studies
- What Homeowners Say About Interlock Metal Roofing
- Aluminum Shingles: Frequently Asked Questions
- Key Takeaways
Who It's For
Interlock® Aluminum Metal Roofing for Every Audience
You want a roof that looks beautiful, lasts decades, and never needs painting, re-granulating, or emergency repairs. Interlock® Aluminum Metal Roofing delivers all three across five architectural profiles — choose the look (slate, cedar shingle, shake, Mediterranean tile, or standing seam) and inherit the same lifetime engineering. The Alunar® coating system holds color for 30+ years, the Lifetime Transferable Warranty adds documentable resale value, and the Class 4 hail rating can reduce homeowner insurance premiums in qualifying markets. One installation, lifetime performance — in the profile that fits your home.
Get Your Free Quote →Interlock® Aluminum Metal Roofing is specified under CSI MasterFormat Section 07 31 16 (Metal Shingles — Slate, Cedar Shingle, Shake, Mediterranean Tile profiles) and Section 07 41 13 (Metal Roof Panels — Standing Seam profile). The 0.019-inch aluminum alloy 3105-H24 panel (ASTM B209) installs at approximately 40–70 lbs per square depending on profile, eliminating the structural reinforcement requirements common with slate, clay, and concrete 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. ICC-ES Evaluation Report ESR-1790, Florida Product Approval FL7263-R7 (NON-HVHZ), and CCMC 10475-R 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. Master spec sheet, panel profile drawings, and CSI-formatted submittal language available on request.
Download Spec Sheet →Interlock's four-way interlocking installation system is engineered for efficient, repeatable installation by trained professionals across all five aluminum profiles. 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 spanning North America. Individual panel replacement is possible without disturbing surrounding panels, simplifying warranty service across every profile. Contact your regional Interlock representative to discuss dealer opportunities.
Become a Certified Installer →Key Advantages
Why Choose Aluminum Shingles
Never Rusts — Unlike Steel
Aluminum forms a natural, self-protecting oxide layer instead of rusting. There is no red rust creeping from cut edges or fasteners, which makes aluminum shingles especially well suited to coastal, lakeside, and high-humidity environments where steel and asphalt fail early.
Explore now >Engineered for Extreme Weather
Interlock's panels lock together across the entire roof plane, earning 120 MPH wind resistance, and they carry a Class 4 hail impact rating (UL 2218) — the highest impact class — so they shrug off storms that crack and dent lesser roofs.
Explore now >Light Enough to Install Over Your Old Roof
At roughly 0.4 lbs per square foot (about 41 lbs per 100 sq ft), aluminum shingles weigh a fraction of tile or slate and can often be installed directly over an existing roof — saving tear-off cost and landfill waste. The low weight also reduces structural strain on the home.
Explore now >Color That Stays True
The multi-layer Alunar finish resists chalking and fading and is backed by a 30-year warranty, so your roof looks new for decades instead of streaking and bleaching like asphalt.
Explore now >The Look of Natural Slate or Cedar
Choose Interlock Slate for the refined lines of natural slate, or Interlock Cedar Shingle for the warmth and grain of real cedar — both stamped into aluminum. You get the architecture you want without the splitting, rot, moss, or fire risk of natural materials.
Explore now >A Roof You Never Throw Away
Aluminum shingles are made with high recycled aluminum content and are 100% recyclable at end of life. Instead of sending tons of asphalt to the landfill every 20 years, you install once and recycle eventually.
Explore now >AAMA 2605 Certified Coating System
The Alunar® Coating System — Built for Lifetime Color
Every Interlock® Aluminum panel — across all five profiles (Slate, Cedar Shingle, Shake, Mediterranean Tile, and Standing Seam) — 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.
Layer 2 — Primer Base Coat
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.
Layer 3 — Conversion Coating
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.
Layer 4 — Alkaline Cleansed
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.
Layer 5 — Aluminum Substrate
The structural foundation of every Interlock® Aluminum panel — 3105-H24 aluminum alloy for the Slate and Cedar Shingle profiles, and 3003-H24 aluminum alloy for the Shake, Mediterranean Tile, and Standing Seam profiles — each selected for its superior formability, corrosion resistance, and long-term dimensional stability. At approximately 40–70 lbs per square depending on profile, it is seven to thirty times lighter than natural slate (800–1,500 lbs/sq) and requires no structural reinforcement on standard roof framing across any of the five available profiles.
Layer 6 — Back Coat
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.
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
Aluminum 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
The Interlock® Aluminum Color Palette
The Interlock® Aluminum color palette is offered in eight architect-curated colors applied through the Alunar® PVDF fluoropolymer coating system. Each color is 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. The same eight-color palette applies uniformly across all five Interlock® Aluminum profiles — Slate, Cedar Shingle, Shake, Mediterranean Tile, and Standing Seam — so you can specify any color in any profile. For projects requiring solid copper rather than PVDF-coated aluminum, see the separate Interlock® Copper Roofing line — a distinct material category in 99.9% pure Copper Alloy C11000 (ASTM B370) with a naturally evolving patina finish. Contact your local Interlock dealer to request physical color samples in the profile and finish of your choice.
Material Comparison
Aluminum Shingles vs. Steel vs. Asphalt
How aluminum shingles compare to the two most common alternatives across the factors that matter most over the life of a roof.
| Aluminum Shingles (Interlock) | Steel Roofing | Asphalt Shingles | |
|---|---|---|---|
| Typical Lifespan | 50+ years; backed by the Guardian lifetime limited material warranty (50 yrs on transfer) | 40+ years, but varies by coating and gauge | 15 to 25 years |
| Rust & Corrosion | Does not rust; naturally corrosion-resistant | Can rust at cut edges, scratches, and in coastal air | Doesn't rust, but sheds protective granules over time |
| Fire Rating | Very light (~0.4 lbs/sq ft); often installs over existing roof | Light, but heavier than aluminum | Heavier than metal; full tear-off usually required |
| Wind & Weather | Interlocking panels rated to 120 MPH | Good wind performance; varies by panel and fastening | Prone to wind uplift, blow-off, and granule loss |
| Appearance & Upkeep | Cedar / slate looks; 30-yr chalk-and-fade finish; low maintenance | Limited profiles; may need rust touch-up or repaint over time | Flat look; algae streaking; periodic replacement |
Real Installations
Interlock® Aluminum Metal Roofing — Project Gallery
Interlock® Aluminum installations across five architectural profiles and the full Alunar® color palette, photographed on residential, heritage, and architectural homes throughout Canada and the United States. Each project showcases the same lifetime engineering — only the profile changes.
Environmental Performance
A More Sustainable Roof
Aluminum shingles 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 Slate Roofing — Project Case Studies
Heritage Home Transformation — Toronto, Ontario
Challenge: The homeowner faced repeated insurance claims from wind damage to aging 3-tab asphalt shingles. The home's heritage character required a roofing profile that complemented its architectural style without adding significant structural load.
Solution: Interlock Metal Slate in Charcoal was selected for its authentic slate appearance, lightweight profile, and Class 4 impact resistance. Installation was completed by a certified Interlock installer in three days with no structural modifications required.
Result: Three years post-installation: zero maintenance required, no insurance claims, and the homeowner reports lower summer cooling costs. The Charcoal Metal Slate profile was cited by their real estate agent as a significant curb appeal enhancement.
Coastal New Construction — Boston, Massachusetts
Challenge: The architect required a roofing material that could withstand coastal salt-spray exposure and high wind loads while meeting the project's requirement for a traditional slate appearance at a sustainable weight.
Solution: Interlock Metal Slate in Deep Charcoal was specified under CSI 07 61 13. The Alunar coating system's salt-spray resistance data satisfied the coastal performance requirement. Full-weight analysis confirmed no structural upgrade was required.
Result: Post-occupancy inspection confirmed zero corrosion, color retention at full specification, and wind resistance performance in excess of regional code requirements.
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.
★★★★★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.
★★★★★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!
FAQ
Aluminum Shingles: Frequently Asked Questions
Common questions about aluminum shingle roofing, answered.
What are aluminum shingles?
Aluminum shingles are interlocking metal roofing panels made from corrosion-resistant aluminum, stamped to look like natural cedar shingles or slate. They install in place of asphalt, wood, or stone roofing and, because aluminum does not rust, can last for decades with little maintenance.
How long do aluminum shingles last?
Aluminum 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 to a new owner).
Are aluminum shingles better than steel?
Both are durable metals, but aluminum does not rust, which gives it an edge in coastal, lakeside, and high-humidity climates where steel can corrode at cut edges and scratches. Aluminum is also lighter. Steel can cost less and is very strong, so the best choice depends on climate and budget.
How much do aluminum shingles cost?
Aluminum 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 you choose, roof size and complexity, your region, and whether you install over an existing roof. The most accurate way to know is a free quote on your specific home.
Do aluminum shingles rust?
No. Aluminum does not rust. It forms a thin, naturally occurring oxide layer that protects the metal underneath, which is why aluminum roofing performs so well near salt water and in wet climates.
Are aluminum shingles good in hail and storms?
Aluminum shingle systems are built for severe weather. Interlock's interlocking panels are rated to 120 MPH winds and carry a Class 4 hail impact rating (UL 2218), the highest impact-resistance class, so they resist the cracking and blow-off that affect asphalt.
Can aluminum shingles be installed over an existing roof?
Often, yes. Because aluminum shingles are very 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.
Are aluminum shingles energy efficient?
Aluminum reflects solar heat rather than absorbing it the way dark asphalt does, which can help reduce attic heat gain and cooling costs in summer. Interlock's finishes are Cool Roof rated (CRRC- and ORNL-tested).
What do aluminum shingles look like?
Interlock aluminum shingles come in two profiles: Interlock Slate, which captures the clean lines of natural slate, and Interlock Cedar Shingle, which captures the grain and warmth of real cedar — both in a range of colors. From the ground they look like the real material, without the splitting, moss, or fading.
Are aluminum shingles environmentally friendly?
Yes. Aluminum shingles are made with high recycled aluminum content, are fully recyclable at the end of their life, and last long enough to avoid the repeated tear-offs that send asphalt shingles to the landfill.
At a Glance
Key Takeaways
- Aluminum does not rust — defining advantage over steel shingles in coastal and highmoisture climates.
- 0.019" (0.483 mm) 3105-H24 aluminum alloy per ASTM B209.
- ~41 lbs per 100 sq ft installed (~0.4 lbs/sq ft) — often installs over existing asphalt shingles.
- Four-way interlocking panel system rated 120 mph wind and UL 2218 Class 4 hail (highest impact class).
- Alunar® 5-layer PVDF fluorocarbon coating — 30-year chalk-and-fade warranty (ASTM D-4214-07 and ASTM D-2244-16).
- Available in two shingle profiles (Slate, Cedar Shingle) and three additional aluminum profiles (Shake, Tile, Standing Seam) on the same coating platform.
- High recycled-aluminum content and 100% recyclable at end of life — measurably lower lifetime environmental footprint than asphalt.
| NEVER rusts (aluminum oxide layer) | 0.4 LBS / SQ FT installed | 120 MPH wind / UL CLASS 4 hail | 30-YEAR coating warranty |
Documentation
Downloads & Specification Resources
Explore More
Explore Interlock Aluminum Shingle Profiles: Slate & Cedar
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.