Metal Roofing in Duncan, British Columbia — Lifetime Interlock® Aluminum Shingles Installed Locally

Yes. Aluminum expands and contracts with temperature swings, but its alloy composition (3105-H24 / 3003-H24 per ASTM B209) resists the cracking and splitting that plague asphalt and wood. Duncan experiences roughly 56 freeze-thaw days per year across its ~1316 mm of annual rain and ~84 cm of snow. The four-way interlocking panels accommodate thermal movement without stressing seams. The Guardian Warranty explicitly covers splitting and cracking—a direct hedge against this climate's cycling.

Metal roofs shed snow and ice more effectively than asphalt because their smooth, interlocked surface offers less friction. Duncan averages about 84 cm of snow annually, often accompanied by gusts to 107 km/h—conditions where snow load and ice dams threaten traditional roofing. Aluminum panels are warranted to resist winds up to 120 mph (193 km/h) when installed to spec, so wind-driven snow and ice stress don't compromise the system. Snow guards can be added where roof valleys or property lines require it.

The four-way interlocking aluminum panels create a mechanical seal that sheds rain without relying on sealants or degradable coatings. Duncan receives approximately 1316 mm of rainfall annually—heavy enough to expose weak seams in conventional roofing. Interlock's overlap design and solid deck installation (typically over existing roofing) direct water away from the house. Combined with proper flashing detail, this system has been installed in coastal salt-air environments and an Antarctic research station without water intrusion issues.

Aluminum contains no iron—the element that rusts. In its place, a self-healing oxide layer forms on the bare aluminum surface; when scratched, this layer reforms automatically. On Interlock panels, a Alunar® 70% PVDF fluorocarbon coating (applied to both sides) provides an additional 30-year warranty against corrosion. This dual protection is especially valuable in Duncan's marine-influenced climate, with ~3001 sunshine hours annually and occasional salt-laden air from the coast. Steel roofing requires constant vigilance against rust; aluminum does not.

Yes. Interlock's four-way interlocking panel system is warranted to resist wind speeds up to 120 mph (193 km/h)—well above Duncan's historical gusts of about 107 km/h. The mechanical interlock on all four sides of each panel creates a unified structure that distributes wind load across the entire roof, rather than relying on fasteners or sealants. This design is validated by ESR-1790 (IBC/IRC compliance, reissued 2025). Coastal and exposed-ridge installations across Western Canada confirm this performance in sustained high-wind conditions.

Interlock metal roofing carries a UL 2218 Class 4 impact rating—the highest available—and the warranty covers perforation from hailstones up to 1.5 inches. Class 4 rating often qualifies homeowners for insurance discounts (check your policy). Duncan's climate includes freeze-thaw stress and occasional severe weather; aluminum's non-combustible, impact-resistant design outperforms asphalt shingles and wood in these conditions. Many insurers recognize metal roofing as a risk reducer; contact yours to explore premium savings once the roof is installed and documented.

Over 50+ years, metal roofing becomes the last roof you buy—eliminating multiple tear-offs to the landfill. Asphalt typically requires replacement every 15–25 years, while Interlock's Guardian Warranty offers lifetime limited coverage (non-prorated) for the original owner and 50 years for the next. Duncan's 1316 mm annual rainfall and 56 freeze-thaw cycles accelerate asphalt deterioration; metal avoids this cycle. The current promotion—interest-free payments for 3 months and at least $2499 savings—reduces the entry cost. Over a homeowner's tenure, the single installation and minimal maintenance yield clear economic advantage.

Virtually none. Aluminum panels are non-porous and resist the mold, algae, and moss growth that plague asphalt and wood shingles in damp climates like Duncan's (~1316 mm rain, ~84 cm snow annually). No sealant reapplication, no granule replacement, no wood treatment required. Occasional gutter cleaning and visual inspection suffice. The Alunar® coating system carries a 30-year warranty against chalking and fading (ASTM D4214/D2244 measured), so color retention doesn't demand maintenance either. This contrasts sharply with asphalt's ongoing upkeep and vulnerability to UV and moisture.

Almost certainly no reinforcement needed. The Mediterranean Tile profile installs at only ~0.59 lb per sq ft—about 96% lighter than concrete or clay tile. Even the heavier Shake profile weighs just ~0.58 lb per sq ft. Most homes' existing roof framing easily supports this load, and Interlock typically installs directly over existing asphalt shingles, reducing tear-off labor and cost. This lightweight advantage is especially valuable for older Duncan homes built to earlier structural codes. Have your installer confirm, but structural reinforcement is rarely required.

Interlock Metal Roofing (BC) Ltd. has served Vancouver Island since 1983 and installs Interlock systems throughout the Duncan region. The product itself has been manufactured in Delta, BC, since 1998—installed from coastal salt-air homes to an Antarctic research station. This local partnership ensures warranty support, familiar climate expertise, and access to the current promotion: interest-free payments for 3 months and savings of at least $2499. Working with an established regional installer familiar with Duncan's rainfall, freeze-thaw cycles, and wind patterns reduces risk and supports local accountability.

Yes. Duncan averages about 84 cm of snow, 1316 mm of rain, roughly 56 freeze–thaw days a year, with peak wind gusts near 107 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.