The way that materials for cladding are chosen is their cost, manufacturing parameters, durability, and appearance.
The most common materials used for cladding include steel and aluminum. Stainless steel and weathering steels are used at times. Other materials are used in particular circumstances which includes copper, bronze, and titanium.
The most popular cladding materials are steel and aluminum. They are used extensively in all of the three classifications of metal cladding types. If you were to compare both steel and aluminum, their strength, durability, and cost of materials will provide you with the basic differences.
If steel cladding is used, they are normally pre-galvanized and pre-painted in coil form before panel manufacturing. When steel is being galvanized, it is dipped into molten zinc or zinc aluminum alloy and a layer of metallic coating is bonded to form a hard, durable outer layer. When the thickness of galvanized steel is measure, it is expressed as the weight of zinc or zinc aluminum per square meter on both sides of the sheet. The typical coating weight on cladding panels are 275g/m2 for zinc and 255g/m2 for zinc aluminum. IN polluted or coastal environment, the zinc aluminum alloy has better durability. It improves corrosion performance on premium pre-finished metals. In order to improve appearance and durability the steel is coated with a variety of finishes. The premium coating is a tough and durable coating. It is usually the case that difficult environmental conditions 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.
Aluminum is resistant to corrosion. When bare aluminum reacts with oxygen, it results in a hard, dense layer that prevents corrosion. Cladding aluminum is generally in the form of an allow with magnesium and manganese. Although aluminum is already durable on its own but it you add an organic or metaling coating, then the durability is improved.
The relative merits of both steel and aluminum is difficult to compare. This often depends on the particular circumstances. Corrosion resistance is the greatest advantage of aluminum, but durability is the advantage of painted steel. Though aluminum is lighter, it is not stronger than steel so it needs deeper or thicker profiles to span the same distance between purlins.
When aluminum is produced, it requires greater quantities of energy than steel so this makes it more expensive than steel. Steel resists impact more than aluminum so when there are temperature changes, steel move less than aluminum. It performs better in fire because it has a higher melting point. Certain types of aluminum panels are formed more easily than steel because it has a low melting point.