Today, Let's Talk About the Comparison of the Applications of Several Common Metal Roofing Systems
Metal roofing system refers to a roofing form that uses metal sheets as roofing materials and combines structural support, waterproofing, insulation and other functional layers. According to the definition of "Technical Specifications for Skylight and Metal Roofing (JGJ255 - 2012)": Metal roofing is composed of metal panels and support systems, does not share the effects of the main structure and has an angle with the horizontal direction of less than 75°. Its main surface materials are: steel plates, aluminum plates, aluminum alloy plates, copper plates, stainless steel plates, etc.
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Strong functionality: Can better achieve all requirements such as drainage, thermal insulation, air permeability, and sound insulation.
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Lightweight and simple structure: Thin structural layers, light supporting structures, large spans, and adaptable to complex architectural shapes.
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Flexible construction and short installation period: Fully assembled installation method, completed in the factory or on-site, less affected by seasons and weather. Extremely high installation efficiency.
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Better economy: Obvious economy in large spans and complex roof forms compared to traditional roofs.
At present, various metal roofs are usually distinguished and classified according to the fixing method of metal roof panels in engineering. Several basic practices commonly used in engineering now are as follows:
This type of roof system was used earlier and is relatively common. The roof panels of this system are fixed to the supporting keel by screws. The connecting screws directly penetrate the roof panel. To prevent leakage, the connecting screws are generally equipped with special compression gaskets and waterproof gaskets, or fixed with closed-type blind rivets with rubber pads.
This type of roof system first appeared in Australia, so it is also called Australian concealed panel. Specific panel types are equipped with corresponding mounting brackets. During installation, the mounting bracket is first fixed to the supporting keel or substrate. The roof panels and brackets are fixed with concealed snaps.
This type of roof system is usually also called a low standing edge standing lock metal roof system. It is divided into single lock and double lock according to the degree of bite. The roof panel is machined. During installation, special fasteners are fixed to the supporting keel, and adjacent roof panels and connecting fasteners bite each other, and then are locked, shaped and fixed mechanically or manually.
This type of roof system is usually called a high standing edge standing lock metal roof system, also called a standing lock seam lok panel. The metal panel is formed into a double-sided male and female buckle by mechanical rolling. During installation, the special aluminum alloy T-code is first connected to the supporting keel. Then the roof panel and the T-code are interlocked, and finally locked and shaped by mechanical or manual methods.
This type of metal plate is generally formed by mechanical stamping or manual cutting. During installation, the special lock fastener is first fixed to the substrate, and then the four sides of the plate are interlocked with the lock fastener through the folding edge to form and fix.
Through the above combined with engineering experience:
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Material Selection: Since metal surface materials are mostly thin (< 1.0mm), the anti-corrosion performance of the material itself is the primary consideration.
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Insulation: In addition to thermal insulation, fire resistance must be considered. Rock wool and glass wool are common materials, with some newer options like foamed glass.
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Accessories: The types and quantities of main accessories are similar, though low standing edge standing lock edge roofs require fewer accessories.
When choosing a metal roofing system, consider the design life, local climate, system performance, and crucially, the building's shape and appearance requirements. In real projects, appearance often dominates the decision. Therefore, specific requirements of the architect or owner for the building's appearance must be understood first.
In general, buildings with low appearance requirements can choose nail-through or concealed button metal roofs (note: nail-through is best for temporary buildings or those with low waterproofing requirements). For public buildings with high requirements for appearance, large area or span, and long service life, a standing lock edge or bite edge metal roof system is best.
If the building roof requires different surface materials (stone, glass, etc., a double-layer roof form), the vertical lock edge metal roof system is prioritized. If the metal roof panel is the direct surface layer, the volume is small, the shape is complex, and appearance requirements are high, the vertical bite edge metal roof system is preferred. The flat lock buckle roof system is generally used when specifically requested by the architect or owner, but should be attached to an inner waterproof layer and used in smaller areas.