External wall insulation material standard dispute

Previously, the difference in standards for building external wall thermal insulation materials was the differentiation of different points of departure when the documents were issued—whether it is necessary to take into account building energy conservation, or is it completely to eliminate potential fire hazards? This not only highlights the unbalanced development of China's building materials market, but also puts forward new propositions for China's building fire protection concepts and building energy-saving technologies.

Not long ago, a residential project in Beijing, which was close to the house, received a piece of paper from a prospective landlord complaining that the external insulation material of the project building did not meet the acceptance criteria. The complaint cited the provisions of the relevant departments, pointing out that the exterior wall of the project uses “flammable” materials and “not standards”. However, the sales director of the project also came up with a set of regulations. His response was: "We do not have any problems with timber."

Behind each word, it is not the same document that the two sides hold.

For the use of exterior wall thermal insulation materials, China had two related regulations: First, the Ministry of Public Security, the Ministry of Housing and Urban-Rural Development jointly issued the “Temporary Regulations for Fire Protection of External Thermal Insulation Systems and Exterior Wall Decoration for Civil Buildings” in 2009. [2009] No.46, hereinafter referred to as “No.46 Document”), and the other is the “Circular on Further clarification of the Fire Supervision and Management of External Wall Insulation Materials for Civil Buildings” issued by the Fire Bureau of the Ministry of Public Security in 2011 [2011] No. 65, hereinafter referred to as "No.65 Document").

According to the document, the former requires that the exterior wall thermal insulation materials “should not be lower than Class B2”, while the latter regulations can only “use non-combustible materials”. According to the rating of the combustion performance of building materials (see Table 1 for details), Grade B2 material is “flammable”, Grade B1 is “flammable”, and Grade A is “non-combustible”. Obviously, the two documents set different standards for external wall insulation materials. As the No. 65 document was an emergency document issued after the Beijing CCTV new site and the Shanghai Jiaozhou teacher apartment fire, the building exterior wall insulation material requirements are more stringent.

However, with the unbalanced development of China's building materials market, the issuance of No.65 document has caused troubles for many developers and designers. “If Class A materials are used, the house may not be able to meet the standards for energy conservation acceptance; however, if energy-saving and well-insulated materials are used, they will not be able to meet the standards of Class A materials.” The sales director mentioned to the reporter. An expert on building energy conservation said that if the implementation of Class A materials is forcibly implemented, "China's building energy-saving industry will be regressed for 20 years."

Just recently, the Ministry of Housing and Urban-Rural Development issued the "Circular on Implementing the State Council's Opinions on Strengthening and Improving Fire Control Work" (hereinafter referred to as the "Notice"), and clearly stated that it must strictly implement the current relevant standards and regulations and Circular 46. This is a targeted reaffirmation and improvement. People in the industry believe that as the provisional document, the former No. 65 document should be invalidated after this "new regulation is promulgated."

The two files of “fighting” were published in the No. 46 document in 2009, which made different requirements for exterior wall insulation materials used in residential buildings of different heights. Among them, for buildings with a height greater than or equal to 100 meters, the burning performance of insulation materials should be Class A; for buildings with a height less than 100 meters, the building should not be lower than Class B2, and at the same time, three zones are divided to make different requirements for the horizontal fire insulation belt. (See Table 2 for details)

However, on March 14, 2011, the Fire Bureau of the Ministry of Public Security issued the No. 65 document. The background was that a building external insulation material fire took place shortly after the Beijing CCTV new affiliated cultural center and the Jiaozhou teacher apartment in Shanghai, causing serious casualties and property. Losses, the central leadership has made important instructions for this.

No. 65 documents that the external insulation material for civil buildings shall be included in the fire engineering design audit, fire inspection and acceptance, and spot-check sampling of construction projects. The document requires that whether the construction project is under construction or not yet started, the external insulation of the building should use "non-combustible materials", otherwise "demolition" or urge "change the design." This also means that the No. 65 document requires that all external insulation materials for civil buildings can only use “non-combustible materials”, that is, A-grade materials.

The two documents have different regulations on the use of thermal insulation materials for external walls of buildings in China, and have plagued many developers and designers since their introduction.

“No.65 document was issued by the Ministry of Public Security’s Fire Bureau in a special case of a particularly large number of building fires. It was of positive significance in the beginning,” said Shi Yong, chief engineer of Beijing Energy Saving Product Technical Service Center. However, he also proposed that the “Opinions on Strengthening and Improving Fire Protection Work” issued by the State Council on December 30, 2011 clearly required that the Ministry of Housing and Urban-Rural Development should work closely with relevant departments to rush to revise relevant standards and regulations. “The Ministry of Housing and Urban-Rural Development shall be the main responsible department in the provisions for the insulation of exterior walls of buildings.”

Zou Xianhua, chairman of Shenzhen Zhuobao Science and Technology Co., Ltd., believes that “No.65 Document” is very difficult at the implementation level, and the “Notice” issued in February is more relevant to China’s reality. "The basic spirit of the "Notice" is a strong supplement to Circular 46. Not only does it classify building materials, but it also emphasizes that insulation materials for external walls must be separated and fire prevention barriers must be established. This is more representative of the government's ultimate consensus."

Shi Yong also believes that the continued implementation of Circular 46 fully meets the requirements of the State Council and has a strong feasibility plan. "And the 46th document issued jointly by the two departments, the legal effect will be higher."

The inadequacy of Class A materials In fact, the two documents are not completely opposed to the use of external insulation materials in buildings. However, the unbalanced development of Class A materials in the building materials market in China has directly aggravated the conflict between the two documents.

Shi Yong said that China’s long-term technological progress in inorganic (ie, fire-rated Class A) fire protection materials is not significant, and the level of industrial development is not high. If forced to use Class A materials, the supply of the market is difficult to meet the quality and quantity requirements.

A person in charge of the Beijing Housing Enterprise Engineering Department told reporters that prior to the release of “65 Document,” most of the external wall insulation materials used in Beijing were B1 or B2 polystyrene boards, which accounted for approximately 80% of the market share; Nationally, Grade A materials account for less than 5% of the domestic market.

Moreover, "At present, Class A materials mainly refer to non-combusting materials, which are mainly heat-retaining cotton, mineral wool, and fiber cotton. Their thermal conductivity is very high, and their water absorption is also very strong, which directly affects the thermal insulation effect of buildings. “Zou Xianhua believes that although Class A materials are conducive to the realization of fire standards, they have side effects on building insulation and energy conservation standards. “There are certain problems at the technical level.”

The high cost of Class A materials is also a problem. The person in charge of the above-mentioned Beijing Housing Enterprise Engineering Department stated that if Class B materials are replaced with Class A materials, the external wall cost will increase by at least 100 yuan to 200 yuan per square meter.

Shi Yong also confirmed this statement: "At this stage, the implementation of the difficulties is mainly a price issue." For example, if rock wool is used as insulation material for exterior walls, it will be relatively thick to achieve the same insulation performance. If dry curtain wall systems are used, there will be an increase in the total construction area and cost, directly affecting the development enterprises and consumers. The vital interests.

"After publication of the No.65 document, the supply of A-grade insulation materials in the market has indeed increased, but due to the backwardness of long-term R&D capabilities, many so-called "A-grade materials" actually do not meet the standards at all." An external wall insulation Material managers say to reporters.

Concerning the difference between the two documents of energy saving and fire prevention for the external insulation materials of building external walls, the concept behind the application of materials is divided. Is it necessary to balance building energy conservation or completely eliminate the potential of fire hazards? This also puts forward new propositions for China's building fire protection concepts and building energy-saving technologies.

According to experts, in the initial formulation of the policy for building exterior wall thermal insulation materials, thermal insulation was first required, and because of the high-rise of buildings, fire protection was forcibly required on the basis of thermal insulation. In 2011, fires of building exterior insulation materials occurred in succession, making the building flammable and combustible exterior insulation materials a new type of fire hazard, and fire protection requirements were upgraded again.

However, if A-grade material is forced to implement, it will also have a greater social impact.

"If implemented in full compliance with the 65th document, there will be a large number of related building materials companies closed down, the inorganic insulation mortar in the central and southern regions will return to the market in large areas, in the northeast can only use thick rock wool or glass wool (the application of thin plaster is not mature Rush to the wall, roof insulation will also return to the perlite era, China's energy-saving construction business will be back 20 years.” An industry source said, regulate the construction, eliminate resistance performance and non-compliance polystyrene board and set the system fire isolation It is imperative.

Most surveyed experts believe that building energy efficiency and fire safety should go hand in hand. In different situations and different types of buildings, different insulation materials and different fireproof structures should be used.

Wang Zhongyong, senior engineer of the Beijing Building Materials Science Research Institute, believes that the relationship between fire fighting and thermal insulation should be analyzed in detail. For example, in the south, sunlight is relatively abundant, and brushing a layer of paint can play a role of being cool in winter and cool in summer, while the northern part needs to take corresponding measures to keep warm. “The material standards used in different regions, projects, and building heights are not the same, and policies cannot be formulated in a one-size-fits-all manner.”

However, Shi Yong also said that at present, material fire protection is the safest and most versatile method of fire protection, and the construction of fire protection is not mature enough and requires more practice to test. "As the construction of buildings in the future becomes higher and higher, the difficulty in extinguishing fires becomes greater and greater, and the development of a technical system with better fireproof performance is the future direction."

Regarding the future development trend of China's building external wall thermal insulation materials, Shi Yong believes that although the external wall thermal insulation materials at the current stage cannot be adapted to Class A regulations, it can be gradually improved. The "Notice" issued in February this year clearly stated that it is necessary to "improve the fire protection performance of external insulation systems for buildings" and that "system fire prevention" as a fire protection method will be more in line with domestic realities.