Metal Roofing in Greenwood, Minnesota — Lifetime Interlock® Aluminum Shingles Installed Locally

Metal roofs shed snow faster than asphalt because the smooth, hard surface doesn't hold moisture the way porous shingles do. Greenwood gets about 95 cm of snow annually with roughly 79 freeze-thaw cycles per year, which is exactly where aluminum excels—the material expands and contracts uniformly without cracking or curling like asphalt does. The four-way interlocking panels stay locked tight through every thaw. Optional snow guards can be installed if you want controlled snow release rather than full shedding.

Aluminum has no capacity to absorb water, so freeze-thaw damage—the main killer of asphalt roofs—simply cannot occur. With 79 annual freeze-thaw days in Greenwood, this matters. When water enters asphalt and freezes, it splits the material. Aluminum oxide (the natural coating on bare aluminum) is already fully oxidized, so it doesn't degrade from repeated temperature swings. The Alunar PVDF coating on both sides adds 30 years of further protection against any environmental stress.

Aluminum is chemically incapable of rusting because it contains no iron—rust requires iron to form. What aluminum does is oxidize, which creates a microscopically thin, self-healing oxide layer that actually protects the metal underneath. If that layer is scratched (say, during installation or a branch strike), new oxide forms instantly, resealing itself. The Alunar 70% PVDF coating on both panel sides adds an extra barrier, making corrosion from Greenwood's 796 mm annual rainfall and occasional freeze-thaw a non-issue for decades.

Interlock's four-way interlocking design is warranted to resist wind speeds up to 120 mph, well beyond Greenwood's typical gust patterns of 94 km/h. The panels lock together on all four edges, so wind cannot lift or separate them—each panel braces the four around it. Typical spring and winter gusts in this region stay below that threshold, and the engineering (backed by ICC-ES ESR-1790 code evaluation) means you're covered even in severe weather. No special installation is needed; spec compliance is standard.

Interlock aluminum roofing carries a UL 2218 Class 4 impact rating—the highest available—and the warranty covers perforation from hailstones up to 1.5 inches. Unlike asphalt, which dents and loses granules (reducing reflectivity), aluminum's hardness absorbs impact without material loss. Many insurers recognize this durability and offer discounts on metal roofs. While hail events aren't predictable, the Class 4 rating gives you documented protection, and that documentation often translates to lower premiums over the 50-year warranty term.

No structural reinforcement is needed. The Shake profile installs at roughly 0.58 lb per square foot, and the Mediterranean Tile (which visually resembles heavy clay) at 0.59 lb per square foot—about 96% lighter than actual concrete or tile. Greenwood homes built to handle standard asphalt easily carry metal roofing. In fact, Interlock installs over most existing roofs without removal, because the weight is so minimal. This also speeds installation and saves disposal costs, letting you avoid the asphalt tear-off cycle entirely.

Installation typically takes 3–5 days depending on roof size and complexity. Yes, Interlock roofing installs directly over existing asphalt shingles in most cases—the light weight (0.41–0.59 lb per square foot across profiles) means no structural concern. The existing shingles provide additional underlayment, which also enhances sound dampening. Removal is recommended only if your shingles are severely deteriorated or if local code requires it. Our Greenwood-area installer, serving since 2001, sizes each project individually and can walk you through that decision.

Aluminum requires almost none. Unlike asphalt, which loses granules, oxidizes, and curls after 15–20 years, Interlock panels don't degrade. Unlike clay tile, which cracks in freeze-thaw (79 days annually in Greenwood), aluminum flexes and self-heals. Periodically clear debris from valleys and gutters—that's it. No sealant reapplication, no granule replacement, no algae treatment. The Alunar 70% PVDF coating is warranted 30 years against chalking and fading, so even color stays true longer than you'll look at it. Maintenance isn't zero, but it's genuinely minimal compared to any alternative.

The Guardian Warranty is a non-prorated, lifetime limited material warranty for the original owner—it covers rusting, rotting, splitting, cracking, curling, and loss of impact resistance. That's comprehensive. If you sell the home, the warranty transfers once to the next owner for 50 years from completion, adding resale appeal. The 30-year coating warranty (Alunar PVDF, measured to ASTM D4214/D2244 standards) is separate and covers fading and chalking. Combined with aluminum's intrinsic durability in Greenwood's wet, freezing climate, this warranty structure reflects genuine confidence in the product's lifespan.

Yes. Interlock's energy-efficient colors reflect heat that asphalt absorbs, reducing cooling load. The Aged Copper Penny finish, for example, achieves initial solar reflectance up to 0.55 and thermal emissivity of 0.84—meaning it bounces sunlight and re-radiates absorbed heat efficiently. Greenwood receives about 3128 sunshine hours per year, so reflective roofing compounds over time. The savings vary by color choice, home size, and cooling habits, but energy-efficiency certification means independent third-party testing backs the claim. Over a 50-year ownership span, energy efficiency contributes to total cost-of-ownership advantage against conventional roofing.

Yes. Greenwood averages about 95 cm of snow, 796 mm of rain, roughly 79 freeze–thaw days a year, with peak wind gusts near 94 km/h. Interlock® aluminum roofing is wind-rated to 193+ km/h (120 mph), UL 2218 Class 4 impact-rated and Class A fire-rated, and its four-way interlocking panels shed snow and resist ice dams and freeze–thaw cracking — all backed by a lifetime limited, transferable warranty.