What determines the best materials for cladding includes their cost, manufacturing parameters, durability, and appearance.
The most common materials used for cladding include steel and aluminum. It also includes stainless steel and weathering steels. IN certain circumstances, copper, bronze, and titanium cladding are also used.
Steel and aluminum are the most popular cladding materials. They are used extensively in all of the three classifications of metal cladding types. Strength, durability, and cost of materials define the basic difference between steel and aluminum.
If steel cladding is used, they are normally pre-galvanized and pre-painted in coil form before panel manufacturing. When steel is galvanized it produces a hard, durable outer layer since it is first dipped in molten zinc or zinc aluminum alloy, then bonded with metallic coating. The thickness of galvanized steel varies and this is expressed as the weight of zinc or zinc aluminum per square meter on both sides of the sheet. The minimum coating weight on cladding panels is typically 275g per square meter for zinc and 255 g per square meter for zinc aluminum. You should use zinc aluminum alloy in polluted or coastal areas because it has better durability. The corrosion performance on premium pre-finished metals are improved. In order to improve appearance and durability the steel is coated with a variety of finishes. With premium coating, you get a tough and durable steel panel. Normally, there are difficult environmental conditions that exist outside of the sheets. And, the underside of the sheet can be subject to condensation and trapped moisture so there is a need to apply coating to this face at various specifications to suit both cost and environmental conditions.
One good quality of aluminum is its resistance to corrosion. When bare aluminum reacts with oxygen, it results in a hard, dense layer that prevents corrosion. An aluminum alloy is formed by combining it with magnesium and manganese to form cladding aluminum. For improved durability, add an organic or metal coating to aluminum.
The relative merits of both steel and aluminum is difficult to compare. It is the particular circumstances that define their merits. Aluminum is inherently more corrosion resistant than steel, but painted steel is durable. Though aluminum is lighter, it is not stronger than steel so it needs deeper or thicker profiles to span the same distance between purlins.
Aluminum is actually more expensive than steel because when it is produced, greater quantities of energy is required than what is required with steel. When there are temperature changes steel is more resistant to impact and moves less than aluminum. When there is fire, steel performs better than aluminum because of its higher melting point. There are certain types of aluminum panels that can be formed more easily than steel due to its low melting point.