Notice on further strengthening the management of residential property decoration in this city, how to prevent the fire hazard of external wall insulation layer of "old building"

According to the on-site staff, the building was built in 2002. At that time, according to the relevant national laws and regulations and the national technical standards for fire protection in engineering construction, external wall insulation was not included in the scope of fire protection design review.

Firefighters picked up an external wall insulation board from the ruins of the fire site for ignition test. The results show that the external wall insulation board is easy to be ignited and will spread rapidly after being ignited. When our lighter is removed, it will continue to burn, including black smoke and toxic smell.

According to the explanation of the engineer of the fire rescue detachment, the flammable external wall insulation board is also an important reason for the rapid spread of the fire. Then let's discuss such a problem.

1. What kinds of external wall insulation layers are there?

Second, what are the standards and regulations?

Third, how to prevent the fire hazard of the external wall insulation layer of "old buildings"?

What kinds of external wall insulation layers are there? Several grades of thermal insulation materials are mentioned above. Let's take a concrete look at how it is expressed in this relevant specification. 20 18 revised Code for Fire Protection Design of Buildings stipulates that the internal and external thermal insulation systems of buildings should adopt Class A thermal insulation materials, but not Class B2 thermal insulation materials, and Class B3 thermal insulation materials are prohibited.

The specific explanation of knocking on the blackboard is:

65438 +0. Class A materials are incombustible materials, which have low fire risk and will not lead to flame spread. Therefore, in the internal and external thermal insulation system of buildings, grade A thermal insulation materials should be selected as far as possible.

2.B2 thermal insulation material belongs to common combustible materials. When the ignition source has high power or strong thermal radiation, it is easy to burn, the flame propagation speed is fast, and the fire danger is great. If it must be used, strict structural measures should be taken to protect it.

3.B3 thermal insulation material belongs to flammable material, which is easily ignited by low-energy fire source or welding slag, with extremely fast flame propagation speed and great fire risk. Therefore, B3 thermal insulation material is forbidden to be used in the internal and external thermal insulation system of buildings.

In addition, there are more specific and detailed regulations for different types of buildings. In fact, it is very common to install insulation layer on the external wall of our country, especially in the northern cities. It is not uncommon for fires to occur in the insulation layer of external walls, and similar incidents have occurred abroad.

The thermal insulation of high-rise buildings leads to frequent accidents of rapid fire spread. 10, 1 10, 15, 14, a fire broke out in a high-rise apartment in Jiaozhou Road, Shanghai. In just four minutes, the fire quickly spread to the whole building. The fire killed 58 people, injured more than 70 people and caused economic losses of several hundred million yuan. When the fire broke out, there were a lot of flammable thermal insulation materials on the facade of this apartment, which was one of the important reasons for the fire.

On 2014065438+01April 2 14, a super high-rise residential building in a street in Shahekou District of Dalian caught fire, which spread rapidly and burned in a large area. Witnesses at the scene said that the fire started near the air conditioning plug-ins on the fifth and sixth floors of the apartment, and the fire spread rapidly along the insulation materials on the exterior wall of the apartment. Smoke billowed at the scene, and the external walls of the third to thirty-fourth floors on the south side of the building were basically burned.

20 17 On June 4th, a fire broke out in a high-rise apartment in Grenfill, London, killing more than 70 people. Fire experts found that the cause of the fire was the plastic part of a household's refrigerator on the fourth floor of the building. The fire spread rapidly through the outer layer and insulation layer of the building, and burned from the fourth floor to the top floor within half an hour. The fire continued to burn for more than ten hours before it was completely extinguished. Lawyers representing fire victims and their families said that it was the flammable materials used in the outer layer and insulation layer of the building that turned a fire that could have been controlled into a "fatal hell".

Now there are more and more tall buildings, and China is also big. According to statistics, there are more than 300,000 high-rise buildings and 6,000 super-high-rise buildings in China, with a height of 100 meters. The average annual growth rate of super high-rise buildings in China is 8%, which is 2.5 times that of the world. According to experts, before the Interim Provisions on Fire Prevention of Exterior Wall Insulation System and Exterior Wall Decoration of Civil Buildings was issued in 2009, there was no uniform mandatory standard for the flame retardancy of exterior wall insulation materials in China. So before 2009, what kind of insulation materials were generally used? For "old buildings" built before 2009, how to prevent fire hazards if the flame retardancy of thermal insulation materials can not meet the current standards?

Hu, an expert from the Emergency Management Department: Before 2009, polyurethane foam, a highly combustible thermal insulation material, was widely used in all parts of China. When the insulation layer of the wall falls off and is damaged, it will spread vertically along the external wall in a short time once it encounters an open flame. It is difficult to demolish and replace the old buildings built before. You can carry out renovation and expansion projects and replace them as much as possible. For those that are difficult to replace, it is necessary to strengthen management, control the fire source and power supply to the maximum extent, set up eye-catching signs, delimit safe areas, and implement inspection, nursing and safety precautions. It's dry in winter now, especially near the Spring Festival. When setting off fireworks and firecrackers, everyone must take precautions and stay away from such buildings to prevent fires.