Preventing Rust on Exposed Steel Structures
01Why steel corrodes
Steel rusts when iron reacts with oxygen and moisture, and the process accelerates with humidity, salt exposure, and standing water. Left unmanaged, section loss reduces load-bearing capacity long before it becomes visually obvious.
02Coating systems that actually last
For exposed structures we generally recommend hot-dip galvanizing over paint-only systems — the zinc coating is self-sacrificing at cut edges and welds, which is exactly where paint-only systems fail first. Where colour-matching or an architectural finish is required, a duplex system (galvanize plus powder coat) gives both protection and appearance.
03Design details that prevent trapped moisture
A large share of premature corrosion we see on-site traces back to detailing, not coating choice — box sections without drain holes, horizontal surfaces without fall, or connections that trap water against the steel. Specifying drainage and ventilation at the design stage costs nothing and prevents years of maintenance.
04Inspection cadence
For coastal or industrial-exposure structures, we recommend a visual inspection every 12 months and a full coating condition survey every 3 – 5 years. Catching coating breakdown early is a fraction of the cost of structural section replacement later.
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