There are a new type of aluminum roofing sheet in the market, that is Aluminum-magnesium-manganese alloy roofing sheet. Al-Mn-Mg alloy has been widely used in the construction industry and has played an important role for the development of modern architecture in the aspects of comfort, lightness, durability, economy and environmental protection. 3004 and 3005 Aluminum-magnesium-manganese alloy (Al-Mg-Mn) is universally accepted as the roofing and curtain wall materials with the service life of 30 years or more in architectural design because of its moderate structural strength, weather resistance, stain resistance and easy bending features. Due to the marine climate, in architectural design, the 5052 ship-class aluminum alloy material can be choosed because of its better corrosion-resistant properties. The physical properties of aluminum roofing sheet with Mn and Mg alloys are: 1, Light texture: with the same thickness, aluminum roofing sheet is lighter than the weight of many other metal plates, and it is easy to handle, which reduce costs much. 2, Strong structure: it is easy to cut, dig ditch, bent into arcs, right angles and other shapes, and with ordinary metal or wood processing tools can make a variety of styling changes to meet the designer requirements. 3, Flatness: that roofing sheet is flat, has smooth surface and not distorted or skewed. 4, Environmental protection: Recyclable recycling, environmentally friendly. The chemical properties of aluminium roofing sheet with Mn and Mg alloys are: 1, Super weather-ability: superior super weather-ability, super corrosion resistance and stain resistance, the aluminum roofing sheet can withstand extreme weather conditions, from UV and temperature differences, and less fade than other coatings, can keep the appearance fresh and clean. 2, Easy to maintain: Use water or mild mild detergent to make the board as permanent as new.