Corrosion-Resistant and Mold-Resistant Materials for Cold Chain Buildings: How to Choose Between Galvanized and Color-Coated Steel Coils?

Choose Between Galvanized and Color-Coated Steel Coils?

With the rapid development of industries such as fresh food e-commerce, cold chain logistics, and pharmaceutical storage, the application scope of cold chain buildings continues to expand. From large-scale cold storage facilities, refrigerated workshops, to cold chain logistics centers, these structures impose higher demands on building materials: corrosion resistance, mold resistance, moisture resistance, and corrosion resistance have become critical factors in material selection during design.

Steel, as one of the core structural and enclosure materials in cold chain buildings, must possess exceptional corrosion resistance in this high-humidity, low-temperature environment with frequent thermal cycling. Among the industry’s mainstream materials—galvanized steel coils and color-coated steel coils—how should one make the right choice?

1.Environmental Characteristics of Cold Chain Buildings

Low Temperature and High Humidity: Cold storage temperatures remain below 0°C year-round, with high humidity that easily leads to condensation;

Frequent temperature fluctuations: Frequent opening of cold storage doors causes hot and cold air to mix, forming moisture that corrodes walls; areas around doors and shelving aisles experience alternating hot and cold air, easily leading to condensation and thermal expansion/contraction;

High hygiene requirements: Storing products such as meat, dairy products, fruits, and vaccines necessitates strict standards for antimicrobial and mold-resistant properties of materials;

Selecting appropriate building materials is a critical factor in ensuring the durability and cleanliness of cold storage facilities.

2.Galvanized steel coils vs. color-coated steel coils: basic performance comparison

Galvanized steel coils are suitable for structurally robust, non-visible areas with low aesthetic requirements;

while color-coated steel coils are suitable for visible surfaces and clean spaces in cold storage facilities with higher requirements for corrosion resistance, hygiene, and aesthetics.

3.Galvanized steel coils vs. color-coated steel coils: common misconceptions in material selection

A.Focusing solely on steel plate thickness while ignoring corrosion resistance  

Thickness ≠ corrosion resistance: Mistaking “thick steel plates” for “durable plates.” Prioritize zinc coating weight and coating type, as these are the key indicators determining corrosion resistance lifespan.

B.Prioritizing price over service life

Selecting color-coated steel coils with inexpensive coatings results in fading, peeling, and mold after two years, with maintenance costs exceeding initial investment, making it uneconomical.

C.Inaccurate environmental assessment  

Ignoring the climate around cold storage facilities, such as coastal or high-salt areas, and failing to use PVDF coatings can lead to coating blistering and substrate corrosion after use.

4.Rust and mold prevention “hidden details”: not just a steel coil issue  

Many cold storage facilities still struggle with rust and mold even when using color-coated steel coils, with issues often stemming from overlooked construction or usage details:

Unsealed edges and exposed cut surfaces: During construction, unsealed edges and exposed cut surfaces become entry points for rust. At cut edges and openings, corrosion-resistant sealant or edge paint must be applied to seal the surfaces, extending the service life.

Low-quality fasteners: Using ordinary carbon steel screws causes rust to form and spread at the screw locations. Stainless steel self-tapping screws or hot-dip galvanized corrosion-resistant screws should be used, along with waterproof washers.

Deterioration of sealant/foam caulking: Using low-quality sealant can cause water absorption, discoloration, mold growth, or even peeling, leading to contamination and affecting aesthetics. Closed-cell high-density cold storage-specific foam sealant should be used.

Installation damage to the coating: Surface scratches caused during construction that are not promptly repainted can trigger rust and corrosion spread. Construction sites should prepare repainting tools and materials, and any scratches should be repaired immediately upon discovery.

Improper ventilation/drainage design: Condensate cannot be drained promptly, leaving steel plates in a prolonged “waterlogged” state.

Cold chain building requirements for steel coil materials go beyond mere “rust prevention,” emphasizing mold resistance, ease of cleaning, aesthetic appeal, and also impacting building safety, food safety, pharmaceutical compliance, and operational costs. There is no absolute superiority between galvanized steel coils and color-coated steel coils; the key lies in whether they are appropriately matched to the application scenario, scientifically selecting the coating type, and controlling construction details. For cold chain projects aiming for long-term stable operation and reduced post-construction maintenance costs, selecting the right materials from the outset is far more advantageous than frequent repairs and reinforcements. Making informed material selection decisions from the outset is not only more economical but also better aligned with the high-standard requirements of cold chain system construction.