Metal fence materials and finishes for the Pacific Northwest

A bare steel fence will rust. The Pacific Northwest climate, approximately <a href="https://climate.weather.gc.ca/climate_normals/results_1991_2020_e.html?searchType=stnName&txtStationName=vancouver&timeframe=3&period=Annual" target="_blank" rel="noopener">1,200 mm of annual rainfall</a> at most Metro Vancouver stations, keeps bare steel in near-continuous contact with moisture. That means a properly applied protective finish is not optional; it is the difference between a fence that lasts decades and one that needs replacing in 8 to 10 years. For most residential fences in Burnaby and Vancouver, powder coat over a zinc-phosphate primer is the standard spec. For any property within a couple of kilometres of the inlet, a duplex finish adds meaningful protection.

A duplex finish is hot-dip galvanizing applied first, then powder coat applied over the galvanized surface. The galvanizing is a zinc layer bonded to the steel, it provides sacrificial cathodic protection, meaning the zinc corrodes before the steel does. The powder coat over top provides a colour layer and slows the weathering of the zinc. The combination lasts significantly longer than either finish alone. Whether you need it depends on site exposure: for a rear-yard fence in inland Burnaby, powder coat alone is generally fine. For anything coastal, North Vancouver waterfront, West Vancouver, False Creek area, Richmond near the river, duplex is worth the added cost.

Aluminum is naturally corrosion-resistant, it does not rust, and for simple fence profiles it requires no paint or galvanizing to hold up in the Metro Vancouver climate. The trade-off is stiffness. Aluminum has roughly one-third the stiffness of steel, which means aluminum fence sections of the same section size will deflect more under wind load and feel less rigid. For a simple horizontal slat residential fence, this is manageable with appropriate post sizing. For a fence with custom design detail, tight radii, integrated hinge plates, or welded structural connections, steel is the better choice. Aluminum also costs more per kilogram of material, the cost difference versus steel narrows when you factor in finishing.

Flat black or near-black (RAL 9005, RAL 7021 dark grey) is the most common colour across contemporary residential metal fences in Metro Vancouver. It reads as clean and architectural, does not visually compete with landscaping or cladding, and fades slowly compared to lighter colours. Charcoal grey (RAL 7016) is close behind. Some heritage and garden fence installs use dark green (RAL 6009 or RAL 6012) to tie in with landscaping. We can match almost any RAL colour, custom colour matching adds a few days to the finishing schedule.

Not necessarily, we typically finish posts and panels to the same spec in the same batch. But the posts bear the full structural and moisture load of the fence, and they are the hardest component to replace if they corrode prematurely. For that reason, if you are anywhere near the saltwater exposure band, we recommend specifying the posts to the higher finish spec (duplex) even if the panels are powder coat only. The cost difference on the posts alone is modest, and they are the part most likely to fail first on an under-finished fence.

The <a href="https://www.galvanizeit.org/hot-dip-galvanizing/how-long-does-it-last-" target="_blank" rel="noopener">American Galvanizers Association's corrosion data</a> puts the service life of hot-dip galvanizing in a temperate coastal climate at 30 to 50+ years before the first maintenance. Metro Vancouver is a temperate marine climate, so a properly galvanized fence section exposed to typical urban air should see at the lower end of that range, while anything in a low-pollution inland setting will see longer. Duplex (galv + powder coat) extends the timeline further because the powder coat significantly slows the rate at which the zinc layer is consumed.