Metal Roofing in Kent, Washington

Aluminum roofs shed snow and ice far more effectively than asphalt because the smooth, hard surface prevents ice dams that trap meltwater. Kent averages about 120 cm of snow annually and 58 freeze-thaw days per year—conditions that cause repeated expansion and contraction. Interlock's four-way interlocking aluminum panels (3105-H24 alloy, ASTM B209) remain dimensionally stable through these cycles, while the oxide layer won't degrade. Snow guards are available if you prefer controlled snow release rather than natural shedding.

Aluminum cannot rust because it contains no iron; it develops a self-healing oxide layer that protects against corrosion. This is critical in Kent, where annual rainfall reaches 1761 mm and wind gusts can exceed 128 km/h—conditions that accelerate rust on steel roofing. Interlock's roofing-grade aluminum is bonded with Alunar® 70% PVDF fluorocarbon finish on both sides, warranted 30 years against chalking and fading. That dual-side coating is engineered specifically for salt-air and high-moisture climates like yours, ensuring no rust, rot, or structural decay.

No. Aluminum's atomic structure doesn't absorb water, so repeated freezing and thawing cycles—Kent experiences about 58 per year—won't cause spalling, cracking, or warping. Unlike slate, wood shakes, or concrete tile, which expand and contract unevenly as ice forms inside their pores, aluminum panels remain mechanically stable. Interlock's four-way interlocking system accommodates the modest thermal movement aluminum does experience, and the Alunar® finish (warranted 30 years) shields the substrate from moisture infiltration that would trigger damage in porous materials.

Yes, when installed to specification. Metal roofs don't absorb water and perform exceptionally well under high rainfall loads. Kent averages 1761 mm of rain yearly, and Interlock's interlocking panel design channels water directly to gutters rather than trapping it. The system qualifies under ICC-ES evaluation report ESR-1790 (IBC/IRC, 2025 reissue) and requires only solid deck and proper flashing. The sealed panel joints, combined with a solid substrate and quality underlayment, create a redundant weather barrier—far simpler and more reliable than the overlapped shingle approach that asphalt requires.

Interlock's four-way interlocking aluminum panels are warranted to resist sustained winds up to 120 mph (193 km/h), and Kent's extreme wind gusts are typically below 128 km/h, so the system exceeds local conditions. Each panel locks mechanically to its neighbors on all four sides; the warranty covers all weather-related failures. This interlocking approach distributes wind load across the whole roof, not individual fasteners. Combined with proper installation, you get not just compliance with building code but structural redundancy designed for the worst weather the Pacific Northwest throws at you.

Interlock achieves UL 2218 Class 4 impact rating—the highest available—and the warranty even covers perforation from hailstones up to 1.5 inches. Although Kent's freeze-thaw days (about 58 yearly) indicate cool, wet winters rather than hail-prone summers, this rating still matters for occasional severe storms and underscores the material's hardness. Many insurers offer discounts for Class 4-rated roofs and non-combustible aluminum; contact your agent with the UL 2218 and non-combustible aluminum details to explore savings. The warranty's impact coverage provides additional financial protection.

No reinforcement is necessary. Interlock's aluminum panels are extraordinarily light—the Mediterranean Tile profile installs at only 0.59 lb/sq ft, roughly 96% lighter than concrete or clay tile—so existing residential framing handles the weight with ease. This allows installation directly over most existing asphalt shingle roofs, avoiding costly tear-off and disposal. Kent receives 1761 mm of rain and 120 cm of snow annually; the lightweight design means water and snow loads distribute safely across your existing structure, eliminating structural retrofit costs that slate or traditional tile would require.

Interlock's Guardian Warranty is lifetime limited for the original owner—non-prorated on material defects like rusting, rotting, splitting, cracking, curling, and loss of impact resistance. It transfers once to the next owner for 50 years from completion, which is significant for resale value. The Alunar® coating carries a separate 30-year warranty against chalking and fading (ASTM D4214/D2244 tested). In practice, aluminum roofs installed in the 1990s at coastal and Antarctic research stations remain watertight today. With Kent's 2743 annual sunshine hours balancing 1761 mm rainfall, proper ventilation and flashing ensure your roof will outlast asphalt by decades.

Virtually none. Aluminum doesn't degrade, split, or curl—it requires only occasional gutter cleaning and inspection, just like asphalt but without seasonal repairs or replacement. Asphalt roofs need patching within 10-15 years; wood shakes split and rot in Kent's 1761 mm annual rainfall and 58 freeze-thaw days. Concrete tile cracks from freeze-thaw. Interlock aluminum is CALGreen-verified for reduced maintenance. The Alunar® finish (30-year warranty) resists algae and weathering, so you won't pressure-wash or resurface. Over a 50-year horizon, the cost difference is enormous—no labor, no material replacements, just reliable shelter.

Metal costs more upfront but costs far less over the roof's life. Asphalt requires replacement every 15-25 years; metal lasts 50+ years with a lifetime limited warranty and transferable coverage. Over 50 years, asphalt means 2-3 full tear-offs, disposal, and multiple re-installations; metal means one installation and no landfill waste. Kent's 1761 mm rainfall and 120 cm snow stress asphalt faster, shortening its lifespan. Interlock's current regional promotion offers no payments and no interest until Spring 2027 or 10% off installation—effective financing to close the upfront gap. When you include avoided labor, emergency repairs, and the 50-year transfer warranty's resale value, metal roofing is the last roof you'll buy.