Steel Structures
Bridges, industrial roofing, warehouses and walkways: anticorrosive systems specified by exposure category with a documented life cycle.
Atmospheric corrosion: the silent enemy of structural steel
Steel structures in urban, industrial and marine environments are in permanent contact with moisture, chlorides, sulfur dioxide and other agents that accelerate corrosion. The rate of degradation varies with the corrosivity category - and the protection system must be designed for the environment's actual category, not the average. The right specification - the proper combination of primer, intermediate and topcoat, applied at the specified film thickness - determines the system's life cycle. That is what Sherwin-Williams P&M delivers: specification grounded in data, standards and decades of field experience.
Applications
Bridges and viaducts
Inorganic Zinc Clad® + high-build Macropoxy® 646 + Sher-Loxane® or Acrolon®. Documented system for C3 to C5 with a 15-to-25-year life cycle.
Industrial roofing and warehouses
Zinc-rich epoxy primer + epoxy intermediate + PU finish for C2/C3 environments with a 10-to-15-year cycle. Watch roofing joints and seams.
Walkways and access structures
Systems with an anti-slip (textured) finish for pedestrian traffic surfaces - zinc-rich primer + epoxy + topcoat with mineral aggregate.
Steel structures in fabrication (shop coat)
High-solids primer applied in the shop before erection - compatible with subsequent welding and assembly without removal.
Transmission and telecom towers
Spray zinc system + epoxy primer for structures in C3/C4 with long maintenance intervals - up to 20 years with the right system.
Road bridges and viaducts
DNIT/ABNT-type corrosion protection system: inorganic zinc primer + epoxy intermediate + PU or polysiloxane finish - C3 to C5 per exposure category.
Key products
Zinc Clad® IV
High-performance cathodic protection for structural steel. Widely specified for bridges, viaducts and public infrastructure works.
Learn more
Macropoxy® 2600
High-build intermediate for C3 to C5 systems. Applicable at low temperatures and on surfaces with residual moisture.
Learn more
Sher-Loxane® 800
Maximum-durability, low-VOC finish for structures exposed to C4/C5. Color retention and dirt resistance.
Learn moreAcrolon® 7700
Finish with excellent gloss and UV resistance for C3/C4 environments - better cost-benefit than polysiloxane.
Learn moreISO 12944
Understanding corrosivity categories
C2 - Low
Interiors of heated buildings, unpolluted rural areas.
C3 - Medium
Moderate urban and industrial environments, food production plants.
C4 - High
Industrial and coastal plants with moderate salinity, chemical plants.
C5-I - Very high, industrial
Industrial environments with high humidity and an aggressive atmosphere - refineries, chemical plants.
C5-M - Very high, marine
Coastal and offshore structures with high chlorides - ports, seaside bridges.
Talk to people who understand your asset, not just paint
Describe your asset's condition and the environment it operates in. Our technical team will come back with a specification aligned to the applicable standard — and the service life you expect from the system.