Fire EIFS technology status abroad

 

　　Research and attention of domestic exterior insulation and fire protection technology, has been missing content from the initial to the current widespread concern of the whole industry, but most of the technical standards and products mentioned in these instructions are on the combustion performance of insulation materials index requirements, such as oxygen index and is determined by the flammability test B2 level and so on, none of fire performance insulation system for specific requirements. While it is revision of "Code for fire protection design of tall buildings" and "building design for fire protection" in attempting to join the principled requirements EIFS fire, but the current implementation of the standard did not fire design exterior insulation system requirements, the lack of height regulations for classification of different EIFS fire performance and application architecture.

 

　　Looking at some of the EIFS application on the market, the prevalence of fire hazards as follows: First, the organic insulation board thin plaster systems in some countries due to the fire performance requirements, there are strict limits on its scope, but no domestic standards make provision for this. On some level even more than 170 meters high-rise buildings are still using such a system constructed without fire protection, fire risk exists should cause the relevant departments attach great importance. Second, the domestic high-rise building applications organic insulation Plastered mesh pasted many brick works, the risk of this approach is that after the process of tile, a protective layer thickness increases, the event of fire, fire performance excellent pre-tile system in paint finishes system, if the fire continued, not only the organic insulation board combustion produces toxic gases and flames to escape to bring great danger, melt while the heat generated by the organic insulation board and mesh shrinkage deformation will cause overheating fuse tile fall for evacuee relief workers and potentially dangerous. Third, the current public buildings, paste or filling organic insulation materials and no fire isolation widespread practice. Usually this type of exterior insulation and practices of organic insulation materials inside the walls bare, between the organic insulation board and the wall of the large cavity between the wall and the insulation board and the presence of small cavities, are very easy to form a chimney effect to accelerate the fire rate of spread, so that the fire caused more serious consequences.

 

　　By contrast, Europe substandard wall insulation system technology earlier national, for exterior insulation system fire safety requirements has been the preferred conditions for the application of this technology. Exterior insulation systems and insulation materials are fire test methods and classification evaluation criteria, different fire rating of exterior insulation system in buildings has a limited range. Foreign experts believe that: EIFS most important is the quality and safety of the system, so consider building insulation of fire safety is necessary, especially in the big cities of high-rise buildings. Worldwide, the range of applications for different building insulation system's fire rating regulations, policies and regulations due to differences between governments differ. As Germany will fire insulation problem is divided into three levels: First, laws and regulations specify more than 22 meters of the building prohibited the use of flammable insulation material, polystyrene board exterior insulation system can only be used for no more than 22 meters of buildings , higher than the 22 meters of the building most of the use of rock wool exterior insulation systems. The second is the European standard ETAG 004 "There wipe the surface layer of the external thermal insulation composite system of European technical standards certification" in the provisions of external wall insulation systems and insulation materials should be in accordance with EN 13501-1 "building products or components of combustion classification" section Part 1 - The use of fire reaction classification test data were evaluated combustion performance levels A1-E, and the provision to indicate the possibility of flame propagation in the insulation material. In order to prevent the spread of flame, some countries proposed a "fire barrier （fire cut off）" approach, the fire of external wall insulation system requirements should be based on laws, regulations and applicable to building end-use regulations may be. Germany will be divided into A-B3 fire rating class （GB 8624-1997 not equivalent）, the standard requires material and polystyrene board insulation system fire rating should reach B1 level, according to the EN 13501-1 standard, polystyrene board material and insulation system to achieve B / C grade requirements. Third, when the polystyrene board exterior insulation system polystyrene board thickness greater than 10mm, to meet the first level under the conditions of further fire resistant construction, to building fire safety regulations. Construction practice is in every window lintel and lintel catchy added high-strength non-combustible mineral wool fire buffer zone, the thickness of the polystyrene board is consistent with the width of up ≥200mm; should extend over both sides of the longitudinal direction of the window ≥300mm, paved the way with a full stick posts, mainly to prevent the flames from the window indoor fires sprang cause EIFS fire.

 

　　In the UK, the provisions of 18 meters above the building must be used according to the British standard European standard B 0 or above grade material, which must be non-combustible or flame-retardant materials; building instruction in the United States, New York （"BUILDING CODE OF NEW YORK '） clearly it stipulates that the fire resistance of less than two hours of polystyrene board thin plaster exterior insulation system does not allow use in more than 75 feet （22.86 meters） of residential buildings.

 

　　In fact, the current global market, building wall insulation, exterior insulation system consists of rock wool or other noncombustible material has been widely used in various types of buildings, to become the world's most extensive range of external wall insulation system of exterior wall one.

 

　　It should be said, to solve the building's exterior insulation system fire safety issues is imminent. In this regard our country is still a long way to go.

 

　　EIFS fire safety is a matter of livelihood security of important and urgent issue

 

　　As can be seen from the fire research and domestic and foreign fire or exacerbate the spread of fire cases caused due to insulation materials made have occurred, the current domestic prevalence EIFS fire safety hazards is an indisputable fact. Under construction in the country to promote energy efficiency in the background, all buildings are required to achieve the appropriate energy efficiency standards, but the insulation materials, about 80% is organic combustible materials, exterior insulation system is poor fire performance The organic thin plaster insulation systems based materials. From the existing EIFS state of the art fire and fire frequency of occurrence of view, how the fire safety test exterior insulation system to improve fire safety all types of building exterior insulation system is currently a major issue.

 

　　The actual national conditions EIFS fire performance should be higher than foreign

 

　　Unlike China's urban housing to low-rise, multi-storey buildings mainly European and American countries, high-level, high-rise high-rise buildings and even ones, especially the economically more developed eastern regions, urban and dense buildings, floor space is small.

 

　　High-rise building fires have the following characteristics: First, the fire spread quickly. High-rise building stairwells, elevator shafts, tube wells, duct and other vertical wells and more multi-cavity structure in the outer finish, forming towering chimney effect, once the fire, burning fiercely and spread rapidly. Second evacuation difficult. The number of high-rise buildings to accommodate more, the vertical distance, coupled with the toxic effects under fire condition people's panic and fire smoke, safe evacuation more difficult to solve. The higher the number of layers, the more personnel, longer time to escape. The third is fighting difficult. High-rise buildings up to tens or even hundreds of meters, to fight the blaze from the outside when the fire very difficult. Fires usually occur in more than 18 layers depends mainly on inside the building fire safety facilities and self-help.

 

　　In such a situation, how to ensure that building fire not because of insulation materials caused, how to ensure that when the fire broke insulation materials do not contribute to flame spread and expand, how to avoid smoke and heat release when the fire broke do not become an obstacle to escape, How to avoid in case of fire does not harm fire rescue when burning insulation materials are worth focusing on.

 

　　To solve the above problem, according to the characteristics of China's urban construction, should fire the external wall insulation system requirements more stringent. Whether it is domestic independent research and development of innovative system products, systems or products from abroad, all must be suited to the characteristics and circumstances of the building to meet fire safety requirements.

 

　　Exterior Insulation Fire Case

 

　　This year, the country due to several fires occurred in insulation materials, which have allowed people aware of the promotion and application of EIFS materials must attach importance to study fire performance system materials. The occurrence of these fires, mostly interchange jobs during the construction phase, a fire ignited fire or welding slag caused by insulation material, a small part is caused by the external building was put into use. Flame thermal radiation by the adjacent building caused by fire or burn near flammable facades or inside a building fire, the flames from the window overflow to spread, can be ignited combustible insulation material, further fueling the spread of fire , the loss increases caused by fire. In addition to the outdoor smoke dissemination of personnel inside the building to escape and firefighters rescue work has also brought great harm. No matter how the cause of the fire, building insulation organic material became accomplices of the spread of fire.

 

　　Organic from exterior insulation system in the insulation material fire or accelerate the spread of fire cases occurred frequently, the fires can be divided into three periods: the construction site of insulation material stacked period; construction time on the wall insulation materials; facades exterior insulation system put into use periods. Careful analysis of three periods of fire characteristics that can better guide fire prevention work EIFS, is conducive to the government, enterprises, users attach great importance to the issue of fire safety exterior insulation system.

 

　　Shocking case of fire to give us sufficient warning. Therefore, the issue of fire safety in buildings, especially high-rise building exterior insulation system must be put on the agenda, through targeted preventive or corrective measures proposed to reduce building fire due to exterior insulation systems and materials caused and the fire spread to people's escape and rescue to win precious time.

 

　　Cause of fire safety issues

 

　　EIFS is a system outside of the building's exterior wall insulation function and have a certain decorative effect. Core functional materials systems insulation materials, accounting for more than 80% of the system volume, and the supporting material is non-combustible materials such as mortar, tile and the like. It also contains a small amount of combustible material such as plastic components fiberglass mesh, putty and paint.

 

　　Insulation materials for the building facades are mainly three categories: The first category is based on mineral wool and wool-based inorganic insulation material, usually identified as non-combustible material; second category is the powder particles of polystyrene insulation slurry Lord of organic-inorganic composite insulation materials, flammable materials are usually found difficult; third category is polystyrene board （thermoplastic）, polyurethane （thermoset） and phenol-based organic insulation material, usually identified as combustible material.

 

　　When EIFS insulation material using non-flammable material or does not propagate flame retardant materials, exterior insulation and finish systems are almost non-existent fire safety issues. Under China's current technical conditions, polystyrene foam and polyurethane foam and other combustible materials in the building exterior insulation system most widely used, which is the cause produces exterior insulation system fire safety issues. With the gradual improvement of energy efficiency standards, the use of combustible organic insulating material thickness is increasing, the building's exterior fire and the fire spread even more prominent.

 

　　Fire hazards

 

　　Through organic insulation materials combustion process analysis, organic insulation materials will burn in air or oxygen atmosphere will cause casualties and property losses directly. The main drawback is the flammability of organic insulation materials, and therefore recognize organic insulation materials fire burn hazard factors for effective fire protection is extremely important. Organic insulation material and the formation of direct damage can be attributed to the following aspects.