Prefabricated Panel Houses Offer Heat Insulation Suitable for Living—How Is Their Waterproof Performance?

Prefab panel houses—are they waterproof and moisture-resistant? The core of the color-coated steel sandwich panels used in prefab panel houses is an organic polymer foam. Its closed-cell structure offers low water absorption and strong moisture resistance. As a result, prefab panel houses deliver solid waterproof and damp-proof performance. They can be used safely in rainy weather without concern about water leakage. What anti-corrosion measures should prefab panel houses take:

1. Thermal spray aluminum (zinc) composite coating: This coating adapts well to part dimensions and can closely follow a component’s shape and size. Another advantage is that the high temperature of the coating process is localized, so the part itself will not be altered by heat.
2. Steel: Prefab panel houses generally use corrosion-resistant steel, commonly known as weathering steel. Weathering steel contains metals such as phosphorus, copper, nickel, chromium, and titanium, which form a highly protective layer on the steel surface and improve corrosion resistance. Prefab panel houses face sunlight, rain, frost, snow, and other natural conditions directly; weathering steel offers better low-temperature impact toughness than ordinary structural steel.
3. Paint coating methods: The corrosion resistance of paint coatings is generally inferior to that of hot-dip zinc, so they are mainly used for indoor steel structures or outdoor structures that are relatively easy to maintain. This approach is low-cost and is used chiefly for indoor steelwork. The coating provides rust protection and is not required to withstand high temperatures or direct outdoor weather. Coating work starts with rust removal. Paint systems demand more thorough derusting than hot-dip zinc, so abrasive blasting or shot blasting is usually used to remove all rust and oil. For on-site painting, rust can be removed by hand. The coating also has stricter environmental requirements: the painting area should keep dust to a minimum, member surfaces must be free of dust, and there should be no rain within four hours after coating. Different coatings offer different levels of corrosion resistance.
4. Hot-dip zinc (high-temperature galvanizing): Hot-dip galvanizing is a high-temperature process in which steel is immersed at about 600°C. A zinc layer forms on the steel surface; thickness requirements are specified in detail—generally no less than 65 microns for thinner plate and no less than 86 microns for thicker plate. The result is strong resistance to heat and corrosion. Advantages include little change from the high-temperature process, a long service life, and reliable quality. The process is therefore widely used on large outdoor steel structures, followed by cleaning. In steel structure design, hard-to-pickle or enclosed members should be avoided so incomplete pickling does not leave yellow water on the galvanized surface. Hot-dip galvanizing is carried out at high temperature.

Taken together, the corrosion resistance of steel-structure prefab panel houses keeps improving, and modern process treatments are increasingly refined. The main structure of a prefab panel house is steel. The quality of a prefab panel house depends on the quality of the steel and of the coatings applied to it.