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

Yes. Interlock's four-way interlocking aluminum panels shed snow and ice effectively because the smooth, sloped profiles don't trap moisture the way asphalt does. Santiago averages about 104 cm of snow annually with roughly 42 freeze-thaw cycles per year—conditions that crack and curl asphalt shingles but have no effect on aluminum. The panels' light weight (the Shingle profile weighs ~0.41 lb/sq ft) allows snow to slide cleanly without stressing your structure, and optional snow guards prevent unsafe slides. Aluminum's oxide layer never deteriorates from salt and moisture exposure, so your roof stays intact through every winter cycle.

Asphalt absorbs water; when it freezes and thaws 42 times per year as Santiago experiences, the trapped moisture expands and contracts, causing cracking, curling, and premature failure. Aluminum doesn't absorb water. Interlock's roofing-grade 3105-H24 / 3003-H24 aluminum alloy (ASTM B209) is naturally non-porous, so freeze-thaw cycles cannot damage it. The Alunar® 70% PVDF fluorocarbon finish on both panel sides adds another barrier against moisture penetration. Over a typical 50-year roof life, this means your aluminum roof survives hundreds of freeze-thaw events while asphalt replacements crumble around you.

Your roof must handle 2,771 mm of annual rainfall in Santiago, and the four-way interlocking design ensures water flows off rather than pooling. The male and female interlocks along panel edges and ends create a labyrinth seal that sheds water sideways and downward, even in wind-driven rain. When installed to ICC-ES ESR-1790 specification over solid decking with underlayment, no water penetrates to the substrate. The interlocking geometry also handles the region's typical gusts up to 117 km/h without lifting or separating. Aluminum panels themselves cannot rot or swell from moisture, so even if water did breach the interlocks (extremely rare when installed correctly), it causes no decay.

No. Aluminum contains no iron, so it cannot rust chemically. When aluminum is exposed to air, it forms a thin oxide layer that prevents further oxidation and self-heals when scratched—a process called passivation. Interlock coats both sides of every panel with Alunar® 70% PVDF fluorocarbon finish (30-year warranty against chalking and fading per ASTM D4214), adding maximum protection in wet, salt-influenced climates. Over a roof's 50+ year life in Santiago's 2,771 mm annual rainfall, aluminum remains structurally sound while steel roofs oxidize and asphalt deteriorates. This is why Interlock panels are installed from Pacific coastal homes to Antarctic research stations.

Interlock metal roofing is rated UL 2218 Class 4 for impact resistance—the highest classification available—and the Guardian Warranty covers perforation from hailstones up to 1.5 inches. Most hail in the Pacific Northwest falls below that threshold. The non-combustible aluminum construction and superior durability often qualify metal roofs for insurance discounts (check with your carrier). Compared to asphalt shingles, which dent easily and lose granules in hail, metal panels restore their shape and retain structural integrity. In regions with frequent hail, metal roofing has become the preferred choice precisely because the impact resistance eliminates repeat claims and keeps your premiums low.

No. Interlock metal roofing is warranted to resist wind speeds up to 120 mph (193 km/h) when installed to specification. Santiago's typical gusts reach 117 km/h, well within the warranty limit. The four-way interlocking system locks panels together mechanically—not just fastened—so each panel braces the ones around it. Wind pressure lifts the entire assembly together, not individual panels. This distributed-load design is far superior to overlapped shingle systems, where wind peels back exposed edges. Proper installation by Interlock Metal Roofing (PNW) Inc., your local installer since 1997, ensures fasteners and interlocks are engaged to spec, keeping your roof secure through any storm the region can produce.

Most homes need no structural reinforcement. Interlock's Slate profile weighs ~0.41 lb/sq ft, Cedar Shingle ~0.41, Shake ~0.58, and Mediterranean Tile ~0.59 lb/sq ft—about 96% lighter than concrete or clay tile. For comparison, asphalt shingles weigh ~2.5–3 lb/sq ft, so metal roofing is actually lighter than what many older homes were built to carry. The Tile profile, despite its authentic appearance, imposes negligible load. Even if your current roof is asphalt, Interlock panels typically install directly over the existing layer without structural upgrades. A local engineer can verify your home's capacity (usually a formality), but weight is rarely a barrier. This advantage saves tens of thousands in reinforcement costs.

Interlock offers five profiles: Slate, Cedar Shingle, Shake, Standing Seam, and Mediterranean Tile. Each replicates traditional materials through authentic panel geometry—dimensional texturing, shadow lines, and dimensional relief—manufactured from roofing-grade 3105-H24 / 3003-H24 aluminum. The Slate profile mimics slate's clean, staggered planes; Cedar Shingle and Shake replicate wood's varied grain and thickness; Tile features curved, overlapping segments. All profiles are available in multiple colors and finishes. Since the panels are aluminum, they maintain color and texture for decades (Alunar® 70% PVDF finish carries a 30-year warranty against fading and chalking). You get the aesthetic of premium materials without the weight, fragility, or maintenance burden.

The Guardian Warranty is a lifetime limited, non-prorated material warranty for the original homeowner—covering rusting, rotting, splitting, cracking, curling, and loss of impact resistance. It's one-time transferable, providing the next owner 50 years of coverage from project completion. This dual-owner term recognizes that aluminum roofing outlasts typical ownership periods. No other roofing material offers this combination: a lifetime promise for you, backed by Interlock's manufacturing since 1998 in Delta, BC, plus explicit coverage extending into your home's next chapter of ownership. When you sell, the warranty becomes a significant value-add that buyers recognize and pay for.

Yes. Aluminum is approximately 95% recyclable and retains its properties through infinite recycling cycles. When an Interlock roof eventually reaches end-of-life (likely after 50+ years in Santiago's climate), it enters the aluminum scrap stream rather than a landfill. Asphalt shingles, by contrast, generate roughly 11 million tons of landfill waste annually in North America—and must be replaced every 15–20 years due to UV damage and freeze-thaw cracking (42 cycles annually in Santiago). Over a century, a building might require five asphalt replacements versus one metal roof. Aluminum eliminates the tear-off-to-landfill cycle entirely. The manufacturing process, centered in Delta, BC, keeps transportation emissions minimal for the Pacific Northwest region, making Interlock a genuinely responsible choice for homeowners concerned with long-term environmental impact.