With the deterioration of the global environment and the strengthening of the energy crisis, people's awareness of energy conservation and environmental protection has gradually increased, so energy-saving buildings have been vigorously promoted and applied in our country.
Wall insulation is the main way to save energy in buildings. However, if the construction quality of the external insulation wall of the building is not up to standard, the proper effect of insulation and energy saving will not be achieved. Briefly discuss how to strengthen the construction of energy-saving building exterior insulation walls.
1. Advantages of External Wall Insulation
The external wall insulation of energy-saving buildings can be divided into three types: external wall insulation, external wall internal insulation, and internal and external hybrid insulation. Among them, the external thermal insulation of the external wall is the main form of thermal insulation promoted by the Ministry of Construction. It places the thermal insulation system on the outside of the external wall to reduce the temperature difference of the main structure so that the building can achieve the effect of thermal insulation.
External wall thermal insulation is the most widely used building thermal insulation technology in my country. Its thermal insulation method is the most direct and the effect is the best. Its advantages mainly include:
(1) It has a wide range of applications, not only for air-conditioned buildings in the south that need heat insulation in summer, but also for buildings in the north that need heating in winter, both for new buildings and for the renovation of existing buildings.
(2) The polystyrene board with low thermal conductivity is used to completely enclose the building, which effectively eliminates the thermal bridge phenomenon and improves the thermal insulation efficiency of the enclosure structure.
(3) The outside of the wall is made of thermally stable thermal insulation material, and the inside is masonry with high heat storage value. The structure is reasonable and the thermal stability of the room is also high.
(4) The external thermal insulation material is set on the external wall without occupying the indoor space and does not affect the effective utilization of the space of the house.
(5) The insulation layer placed on the outside of the building can effectively prevent damage to the main structure caused by natural temperature, humidity, ultraviolet rays, etc., greatly reducing the probability of cracks, deformation, and damage, thus playing a very good role in protecting the main structure. Extend the life of the building.
2. Existing problems in external thermal insulation of energy-saving building exterior walls
Even though external insulation of external walls has many advantages above, in actual engineering, energy-saving buildings often fail to achieve the proper thermal insulation effect due to improper materials or construction techniques. Improper selection of insulation materials and lax quality inspection and control of incoming materials will directly reduce the insulation effect of the exterior wall; ineffective supervision of the construction process, unfamiliarity with the process, poor skills of construction personnel, and large randomness in construction operations may lead to Engineering quality issues arise. In terms of materials, such as the poor quality of the external thermal insulation adhesive, the silica sand in the aggregate is made of ordinary quartz sand with high iron content, which is prone to oxidation and causes cracks and peeling off of the external thermal insulation system; Local shrinkage and uneven temperature stress lead to cracks at the joints; the glass fiber mesh cloth has poor alkali resistance, and it is prone to cracking and peeling of the plastering layer after being corroded by cement alkali; Airtight elastic coatings and poor quality ceramic tiles are used as external insulation and finishing materials, etc.
In terms of construction, if engineers and technicians do not pay attention to the detailed node requirements of the external thermal insulation of the external wall, it may cause the external thermal insulation of the external wall, bay window, cornice, air conditioner board, etc. to not intersect, resulting in cold bridges; It is easy to fall off due to the bonding strength with the base layer; due to the large deviation of the flatness of the outer wall construction, the anti-cracking mortar is cracked due to the excessive deviation of the thickness of the insulation layer and the temperature expansion and contraction stress; the water-filled room of the building is close to the outer wall There is no vertical moisture-proof layer at the place, which makes the outer insulation layer partially hollow and fall off due to the freeze-thaw cycle; the use of ordinary water-resistant putty to scrape the exterior wall finish will easily lead to problems such as peeling and peeling of the paint and cracks in the finish layer.
