Metal Roofing in Wilmington, Illinois — Lifetime Interlock® Aluminum Shingles Installed Locally

Interlock's four-way interlocking aluminum panels shed snow and ice effectively because the smooth, hard surface offers no grip for accumulation—unlike asphalt or wood shingles that trap moisture. With about 81 freeze-thaw cycles per year in Will County, this matters: the metal's non-porous aluminum alloy won't absorb water that re-freezes and splits, and snow guards can be added to manage sudden slides. The standing seam profile is particularly effective for shedding, while the Slate and Cedar Shingle profiles still drain quickly despite their textured appearance.

Aluminum expands and contracts minimally compared to asphalt or wood—the metal's coefficient of expansion is predictable and the four-way interlocking system accommodates that movement without stress. In Wilmington's ~81 annual freeze-thaw days, wood shingles and tile absorb moisture that freezes inside the material, causing permanent damage; asphalt becomes brittle. Aluminum, by contrast, has no pores to trap water. The roofing-grade 3105-H24 alloy (ASTM B209) is engineered for this cycle, and the Alunar coating won't crack from temperature swings.

No. Aluminum cannot rust because it contains no iron—iron is what oxidizes into rust. Instead, aluminum develops an invisible, self-healing oxide layer that protects the underlying metal. Even if scratched, this layer reforms naturally. In coastal or high-moisture regions, this is critical; in Wilmington, with about 1,100 mm of annual rain, the protection is equally valuable. Interlock applies a two-sided Alunar 70% PVDF fluorocarbon finish for extra defense, warranted 30 years against chalking and fading (ASTM D4214/D2244), making corrosion a non-issue for the life of your roof.

No reinforcement is needed in nearly all cases. Interlock's aluminum panels are extraordinarily light—the Mediterranean Tile profile installs at just 0.59 lb/sq ft, making it about 96% lighter than concrete or clay tile. Even the heavier Shake at 0.58 lb/sq ft is a fraction of traditional tile weight. Because existing asphalt shingles and decking already support this load, Interlock installs directly over most existing roofs without structural modifications. This also means faster installation, lower labor costs, and no disruption to your home's foundation or framing.

No. Interlock panels are warranted to resist wind speeds up to 120 mph when installed to specification. Wilmington's typical peak gusts reach about 102 km/h (63 mph)—well within safe margins. The four-way interlocking design locks each panel to its neighbors on all sides, distributing wind load across the entire roof rather than relying on fasteners alone. This is why the system earns warranty coverage for the installation itself. Combined with proper underlayment and fastening, your roof remains secure in storms common to Will County.

Interlock carries a UL 2218 Class 4 impact rating—the highest available. The Guardian warranty even covers perforation from hailstones up to 1.5 inches. Class 4 means the roof can withstand repeated hail impacts that would punch holes in asphalt or split wood shakes. Insurance companies recognize this durability: many offer premium discounts for Class 4 metal roofing, particularly in regions prone to severe weather. Contact your insurer with the UL 2218 rating to explore potential savings over the roof's lifetime.

Yes—the physics is straightforward. energy-efficient Interlock colors have initial solar reflectance up to 0.55 (Aged Copper Penny) and thermal emissivity of 0.84, meaning they bounce heat away rather than absorb it like asphalt does. Wilmington receives about 3,056 sunshine hours per year, so the difference compounds. A reflective metal roof can reduce attic temperature by 20–30°F on a sunny day, lowering air conditioning demand. The Cool Roof Rating Council rating confirms measurable performance. Over 30+ years, this translates to meaningful energy savings compared to asphalt, which absorbs heat and degrades faster in sunlight.

The Guardian warranty is a lifetime limited, non-prorated material warranty for the original owner—meaning no deductible increases over time and you're covered for rusting, rotting, splitting, cracking, curling, and loss of impact resistance for as long as you own the home. It's also one-time transferable, extending 50 years of coverage to the next owner from completion. Interlock has manufactured this product since 1998 in Delta, BC, with installations ranging from coastal salt-air homes to an Antarctic research station. In Wilmington's 1,100 mm annual rainfall and 81 freeze-thaw cycles, this durability translates to a roof that outlasts multiple asphalt replacements.

Aluminum is non-combustible by nature, and Interlock offers Class A fire classification (the highest rating) on specific colors. This means the roof won't ignite, spread flame, or contribute significant smoke in a fire. The ICC-ES evaluation report ESR-1790 (reissued 2025 for IBC/IRC compliance) confirms Interlock meets Wilmington's building codes. Class A rating can also reduce homeowner insurance premiums in some cases and is required by some municipalities and HOAs. If fire safety is a priority—particularly in areas with wildland-urban interface risk—this non-combustible design adds real protection beyond asphalt shingles.

Aluminum is about 95% recyclable at end of life, breaking the asphalt tear-off-to-landfill cycle that has buried millions of tons of shingles over decades. Interlock's aluminum panels can be reclaimed and reprocessed indefinitely without loss of quality. Asphalt shingles, by contrast, are difficult to recycle and typically end up in landfills, where they persist for centuries. The CALGreen verification confirms Interlock qualifies for reduced-maintenance certification under California's green building standard. Over a 50-year lifespan in Wilmington—through about 1,100 mm of annual rain and 70 cm of snow—you're installing one roof instead of three asphalt roofs, eliminating significant waste and environmental impact.