Exterior galvanized steel stairs for the Pacific Northwest

The Pacific Northwest climate is brutal on bare or painted steel. Hot-dip galvanizing to ASTM A123 forms a metallurgical zinc bond that protects the steel for 50+ years in this environment without coating maintenance. Painted exterior steel — even with a high-quality industrial coating — needs touch-ups every 5–10 years and full recoats every 15–20. Galvanizing is the right answer for any exterior steel that has to last.

After fabrication and quality control, the assembly is delivered to a galvanizing facility (in our case, usually a partner facility in the Lower Mainland). The steel is cleaned in caustic and acid baths, fluxed, and then dipped in molten zinc at around 450°C. The zinc bonds metallurgically with the steel surface, forming layers of zinc-iron alloy plus a pure zinc top layer. The whole process adds about 5–7 days to fabrication lead time.

Galvanized steel has a distinctive industrial finish — visible spangle pattern, slightly textured, ranging from bright silver-grey when new to dull matte grey as it weathers. The look is honest and functional, which works for fire escapes, deck access, school stairs, and industrial applications. For projects where architectural finish matters, galvanized steel can be powder-coated over top (called "duplex coating") to combine the corrosion protection of galv with the color and texture of powder coat.

Smooth galvanized steel can be slippery when wet — which is why we never use plain plate for exterior stair treads. Standard exterior tread options are checker plate (tread pattern molded into the plate), perforated steel (drains water and provides grip), and bar grating (fully open for water and snow drainage). All three are code-compliant and provide enough slip resistance for outdoor use in this climate.

Exterior galvanized stair pricing depends on the number of treads, stair width, whether landings are required, railing configuration, and the overall assembly weight (which affects the galvanizing cost). School and institutional stairs with longer runs and intermediate landings cost more than a simple residential deck-access stair. Compared to painted exterior steel, galvanized is more expensive upfront but saves money over the building life because there is no recoating cycle. <a href="/request-a-quote/">Contact us for a project-specific quote</a>.

Once the fabricated assembly is delivered to a galvanizing facility, the actual dipping process takes a few hours — cleaning, fluxing, heating, dipping, cooling, inspection. But the facility runs on a schedule and the full turnaround from drop-off to pickup is usually 5–7 business days. For time-sensitive projects we book the galvanizing slot in advance so the schedule doesn't slip.

Yes — this is called "duplex coating" and it combines the corrosion protection of galvanizing with the architectural finish of powder coat or wet paint. The galvanized surface has to be properly prepped (etch primer or sweep blast) before the top coat is applied. Duplex coating costs more than galvanizing alone but provides the longest service life of any coating system in the Pacific Northwest climate and is what we specify when exterior steel needs both durability and a specific colour.

ASTM A123 is the standard that defines hot-dip galvanizing for steel products. It specifies minimum coating thickness (usually 75–100 microns for structural sections), inspection criteria, and acceptance standards. When we specify "galvanized to A123" on shop drawings, we're telling the galvanizer which quality standard to meet and giving the building inspector a reference to check against. Any reputable galvanizer in BC works to this standard.

Freshly galvanized steel can cause some runoff staining on surrounding light-colored surfaces during the first 6–12 months of weathering. The stain is from zinc oxide and is more cosmetic than structural. Design details that direct drainage away from light surfaces minimize the issue. For high-visibility locations we sometimes specify duplex coating specifically to avoid this.

Under ISO 9223 atmospheric corrosivity categorization, most of Metro Vancouver is classified as C2 (low) to C3 (medium) — we get a lot of rain but we're not as corrosive as a true coastal marine environment. For an ASTM A123 galvanized coating in C3 conditions, the American Galvanizers Association's service life chart projects 50–75 years to first maintenance. In practice, we see galvanized stairs perform for the full design life of the building.

Yes. ASTM A780 specifies touch-up and repair procedures for galvanized coatings. The most common methods are zinc-rich paint (applied with a brush for small areas) and zinc metallizing (applied with a specialized spray gun for larger repairs). We supply touch-up kits with every galvanized installation so the GC or the homeowner can address small nicks or scratches over the life of the stair.

Open tread designs (bar grating, perforated plate, checker plate with drainage) handle snow well because water drains through rather than collecting on the tread. For ice, the stair surface itself does most of the work — bar grating stays grippy even when iced because the teeth of the grating sit above the ice surface. For locations with heavy snow load (higher elevations, Whistler corridor), the stair has to be designed for the combined live + snow load.

Yes. We regularly produce exterior stairs that coordinate with a specific building facade through detailing — matching the picket spacing to existing architectural elements, colour-matching the handrail, using a specific tread pattern. The trade-off is that every custom detail adds fabrication time. For institutional repeat work (multiple schools, multiple buildings on a campus), we can standardize details that make sense across the project portfolio.