Generally, once the extruded board attached to the outer wall is aging, it will affect the performance and service life of the extruded board.Therefore, in order to avoid the aging of the extruded plastic board on the outer wall, many people do not know the reason. Let's take a look at it together:
- Thermal Stress.The thermal expansion and cold contraction caused by the change of temperature difference will cause the volume change of the non-structural structure, so that it is always in an unstable state. Therefore, thermal stress is one of the main destructive forces of the external insulation layer of the outer wall of high-rise buildings.Compared with multi-storey or bungalow buildings, high-rise buildings have greater thermal stress and greater deformation due to stronger sunlight exposure on the outer layer. Therefore, in the design of thermal insulation and anti-cracking structures, the selection of thermal insulation materials should meet the principle of flexible gradient. The deformation capacity of the outer layer material should be higher than that of the inner layer material.
- Wind pressure.Generally speaking, positive wind pressure generates thrust, and negative wind pressure generates suction, which will cause great damage to the outer insulation layer of high-rise buildings, which requires that the outer insulation layer should have considerable wind pressure resistance.And in terms of wind pressure resistance, it is required that the insulation layer has no cavity, and the air layer is eliminated, so as to avoid the damage to the insulation layer caused by the volume expansion of the air layer in the insulation layer under the condition of wind pressure, especially negative wind pressure.
- Water or water steam.In order to avoid the damage of water or water vapor to high-rise buildings, external thermal insulation materials with good hydrophobicity and good water vapor permeability should be selected to avoid condensation on the wall or increased moisture content in the thermal insulation layer during the migration of water or water vapor. It can improve the rainwater erosion resistance and freeze-thaw resistance of the outer insulation layer of high-rise buildings.
- Fire.High-rise buildings have higher fire rating requirements than multi-storey buildings, and the thermal insulation layer of high-rise buildings should have better fire resistance, and should have the characteristics of preventing the spread of fire and preventing the release of smoke or toxic gases in case of fire.The strength and volume of the material should not be lost and reduced too much, and the surface layer will not burst or collapse, otherwise, it will cause damage to the residents or firefighters, and cause great difficulties to the rescue work.