Metal Roofing in Markham, Washington — Lifetime Interlock® Aluminum Shingles Installed Locally

Yes. Interlock's four-way interlocking panels lock snow in place and shed ice safely without the ice-dam leaks that plague asphalt. Markham receives about 60 cm of snow annually and 38 freeze-thaw days, creating perfect conditions for ice dams on traditional roofs. The aluminum won't warp, split, or absorb melt-water like asphalt or wood shakes do. Optional snow guards keep snow from sliding unpredictably. The panels' engineered profile and weight—as light as 0.41 lb/sq ft on the Shingle style—eliminate structural stress from heavy snow loads.

No. Interlock panels are mechanically interlocked on four sides, so water cannot seep at seams the way it does in asphalt shingles or standing-seam overlaps. With 2305 mm of rain yearly, Markham demands a roof that sheds water actively, not absorbs it. The four-way system forces water outward and downward; the panels overlap in a sequence that prevents backflow. Combined with proper deck and flashing installation to code ESR-1790, Interlock delivers zero-leak performance in heavy rainfall conditions that age asphalt prematurely.

Yes. Interlock panels are warranted to resist winds up to 120 mph when installed to specification. Markham experiences typical daily winds around 15 km/h with gusts reaching 106 km/h—well within that rating. The four-way interlocking system distributes wind load across the entire panel assembly, not just fastener points. This is why the product has been installed from coastal salt-air homes to an Antarctic research station. Asphalt shingles, by contrast, can begin lifting at 60 mph; metal panels simply perform.

Interlock panels carry UL 2218 Class 4 impact rating, the highest available, and the warranty even covers perforation from hailstones up to 1.5 inches. Insurance companies recognize this durability and often offer discounts on comprehensive coverage for metal roofs. While Markham's climate shows no severe hail history in the regional data, the Class 4 rating protects you against any future event. Asphalt shingles typically achieve Class 3 or lower. This structural resilience—combined with the aluminum's non-rusting properties—makes metal roofing a lower-risk asset in your insurer's eyes, potentially offsetting years of premium costs.

Aluminum cannot rust because it contains no iron. Instead, a paper-thin oxide layer forms on the surface and self-heals when scratched—an electrochemical process that continues for the roof's lifetime. Steel, by contrast, rusts aggressively in Markham's 2305 mm annual rainfall and high-humidity environment. Interlock panels use roofing-grade 3105-H24 and 3003-H24 aluminum per ASTM B209, with a Alunar 70% PVDF coating applied to both sides for extra protection in coastal salt-air conditions. After 27 years of manufacture and installation, no Interlock aluminum roof has ever rusted through. Steel roofs fail in 15–25 years in this climate.

Yes. Interlock's Mediterranean Tile profile weighs only about 0.59 lb/sq ft—roughly 96% lighter than concrete or clay tile—so no structural reinforcement is needed. Most homes can accept metal tile installation directly over existing asphalt, eliminating costly tear-off and disposal. For comparison, concrete tile weighs 8–10 lb/sq ft; that difference means no engineer reports, no beam upgrades, no construction delays. Markham's freeze-thaw cycle (38 days annually) is tough on heavy materials; the aluminum's minimal mass actually reduces thermal expansion stress year-round. This is why the product earned ICC-ES ESR-1790 approval for retrofit installation.

Virtually none. Asphalt shingles require annual inspection, moss removal, and gutter cleaning; wood shakes need periodic sealing, splitting repair, and pest protection. Metal roofs need a rinse once or twice yearly in Markham's 2305 mm rain climate to keep the coating looking fresh. That's it. The Alunar 70% PVDF finish is warranted 30 years against chalking and fading (ASTM D4214 and D2244 measured), so color stays stable even under 2789 annual sunshine hours. The aluminum won't rot, split, curl, or lose structural integrity. CALGreen-verified for reduced maintenance, Interlock eliminates the inspection fatigue and repair costs that consume homeowner budgets over 40+ years.

No. Asphalt typically costs less upfront but fails every 15–20 years, creating cycles of tear-off, landfill disposal, and reinstallation. That's 2–3 roof replacements in 40 years. Interlock carries a lifetime limited non-prorated warranty for the original owner and a 50-year transferable term for the next owner, meaning one installation covers your ownership and adds resale value. Factor in zero maintenance, no leak repairs, no structural reinforcement, and energy savings from energy-efficient colors with 0.84 emissivity, and the aluminum roof costs less per year over your home's life. Current financing offers no payments and no interest until Spring 2027, making the decision even clearer.

The Guardian Warranty is a lifetime limited non-prorated material warranty for the original owner, covering rusting, rotting, splitting, cracking, curling, and loss of impact resistance—essentially every failure mode that claims traditional roofs. It transfers once to the next owner for 50 years from completion, protecting your resale value. This warranty exists because the roofing-grade 3105-H24 and 3003-H24 aluminum doesn't degrade through Markham's 38 annual freeze-thaw cycles or 60 cm snow loads. The Alunar coating is separately warranted 30 years against chalking and fading. No other roofing material—asphalt, wood, or concrete—offers this combination of coverage depth and duration, which is why it's called the only roof you'll ever need to buy.

Installation typically takes 2–5 days depending on roof size and complexity. Yes, Interlock can be installed over most existing asphalt, wood, or composition roofs without tear-off, saving weeks of disruption and thousands in disposal costs. The lightweight aluminum—0.41 to 0.59 lb/sq ft—won't overload your structure. The installation sequence follows ICC-ES ESR-1790 specifications to ensure proper interlocking, flashing, and wind resistance up to 120 mph. Interlock Metal Roofing (PNW) Inc. has served the region since 1997, so crews understand Markham's 106 km/h wind gusts and 2305 mm annual rainfall and install accordingly. You're finished and protected before the next heavy rain event.

Yes. Markham averages about 60 cm of snow, 2305 mm of rain, roughly 38 freeze–thaw days a year, with peak wind gusts near 106 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.