Current situation and problem analysis of metal roofing industry

The metal roofing is characterized by short construction period, high degree of prefabrication, flexible and diverse architectural and design styles, and favorable to environmental protection in the overall construction process. It is widely used in various buildings.As we have learned, current our country has quantity of existing metallic roofing to make an account of 3 billion square metre, add metallic roofing to make an account of 80 million square metre every year, amount of maintenance of metallic roofing is as high as 100 million square metre every year.This paper makes a simple analysis on the development status and problems of metal roofing industry.

 

Taking China's civil aviation industry as an example, the 13th five-year plan for the development of civil aviation in China clearly states that from 2016 to 2020, China will continue to build 30 airports and build 44 new ones.In addition, 139 airports will be renovated or expanded, and 19 will be relocated.In the early stage, 51 projects were planned, 46 were built and 5 were relocated.By 2020, the number of civil airports will reach 260. The terminal buildings of the airport are mostly metal roofing with light steel structure.

 

Due to the development of science and technology, all kinds of new roofing materials have emerged, such as color steel plate, aluminum magnesium manganese alloy roofing plate, stainless steel plate, titanium alloy plate, etc., metal roofing has been widely used in large factories, warehouses, supermarkets, halls, stadiums and waiting buildings and other projects.From the economically developed areas, the central and western regions, from big cities, small and medium-sized cities to towns and villages, from public buildings to civil buildings, the development momentum is very rapid.

One, metal house wall problems

 

With the rapid development of metal roof wall system in China, the problems in the application of metal roof engineering mainly include the following aspects.

 

1, roof structure safety problems

The metal roof belongs to the light enclosure structure system. Each component is mechanically connected and fixed, which is sensitive to the external load. When subjected to a large load, component or connection failure is likely to occur.At present, the structural problems of domestic metal roofing project mainly include the damage or collapse caused by heavy snow, and the lifting of roof board by wind when encountering strong wind.

 

2. Leakage of house walls

The leakage of metal roofing mostly occurs in the details of joints, gutters, drainage systems and other parts, which is due to the roof design and construction of the details of no careful and thorough research.Due to the common leakage phenomenon, there are a lot of domestic research on the method of metal roof leakage repair, but due to the variety of metal roof system, complex structure, different projects mostly use different metal plate system and connection, so the reasons for the leakage are different.

 

3. Roof insulation

On the one hand because of metal room metope USES energy-saving standard low, on the other hand, due to technical defects such as design, construction, the domestic many metal roofing engineering problems, poor thermal performance were part of the building energy consumption is high, the internal condensation occurred some buildings cannot be used for high energy consumption, and even affected the use of metal roofing in north China region.

 

Two, metal house wall problems occur

 

1. Lack of industry standards and norms and lack of industry management

 

Metal roofing system is generally composed of metal roofing board and multiple functional layers.About the metal pressure plate, the domestic only GB /T 12755 -- 2008 "building pressure plate" and GB /T 6891 -- 2006 "aluminum and aluminum alloy pressure plate" and other pressure type product standards, there is no on stainless steel plate, copper plate, titanium and titanium alloy plate pressure product standards;Metal roofing system (construction, design, etc.) there is no professional norms, part in GB 50207-2012 "roof engineering quality acceptance specification", GB50205-2001 "steel structure engineering construction quality acceptance specification", GB50345-2012 technical specification for the roofing construction, GB 50693-2011 "slope roof engineering technical specifications" and JGJ 255-2012 "the daylighting top with metal roofing engineering technical regulation of reflected;But the standard of performance test and maintenance of metal roofing system is blank at present.

 

Although, the national engineering construction standard "pressed metal plate application technical specification", GB 50345-2004 "slope roof engineering technical specification" and so on have been compiled and issued, each place also attaches great importance to the quality requirements of the metal roof, for example, Beijing has compiled the local standard "metal roof construction quality acceptance standard" and so on.But not according to the characteristics of the metal, from the design concept, construction technology, material selection and construction management, put forward the corresponding metal house wall maintenance technical and acceptance procedures, hinder the healthy development of the industry and enterprises.

 

2. Metal roofing lacks professional maintenance for a long time

In addition to the design and construction reasons, the lack of maintenance is also a metal roof prone to problems or even to expand the problem of a reason.At present, there is no mature maintenance regulation in the domestic metal roofing industry, and there is no standard or specification for this.Therefore, the design neither maintenance inspection of the number of years and maintenance provisions, also did not consider the maintenance of facilities, so it is difficult to maintain in the use of the process.The complex connection structure and light structure characteristics of the metal roof determine that the metal roof needs daily inspection, maintenance, and timely detection and elimination of potential hazards.