Development history of waterproof and breathable membrane
In the 1950s, German architects found that the self-adhesive and airtight characteristics of asphalt waterproofing membrane and coating waterproofing materials led to the residual water in the concrete structure being enclosed in the structure, and the water vapor in the concrete structure could not be released, which led to the breeding of mold on the roof and wall, and the indoor air quality and human health were seriously threatened. Therefore, the German construction industry began to use the roof cushion with air permeability to replace the self-adhesive coiled material and film waterproof. This air permeability cushion is laid on the roof base layer, so that the water vapor of the cast-in-situ concrete roof panel can be quickly discharged, thus avoiding the breeding of mold.
Under the historical background at that time, people did not know enough about building energy conservation. In the 1970s, with the outbreak of the world energy crisis, European and American countries paid more and more attention to building energy conservation. Energy experts found that although this breathable cushion can discharge the water vapor of the cast-in-place concrete roof and effectively solve the problems of moisture-proof and mold, a large amount of water vapor is discharged to the insulation layer, and the thermal performance of the insulation material is restricted. The water vapor causes the insulation layer and structure to be damp and damaged.
In the middle of the 20th century, Professor Rowley of the University of Minnesota in the United States found that the condensation of water vapor in the exterior walls and roofs of buildings would seriously affect the performance of building insulation materials and the durability of building envelope, leading to the breeding of mold. The main cause of dampness is the liquid phase water and vapor phase water infiltrated into the interior of the enclosure by the air outside the building. Since then, some buildings in the United States have begun to use waterproof membrane, which is laid outside the insulation layer as a building covering system to strengthen the air tightness and water tightness of the building. However, this waterproof membrane is impermeable, and the moisture of the enclosure structure can not be released, which can not completely solve the moisture-proof problem.
After continuous scientific research and practice, experts in the German and American architectural circles have finally found that changing the breathable roof cushion into impermeable coiled material as a vapor barrier layer and laying it on the base layer of the roof, so that the water vapor of the cast-in-situ concrete roof can be discharged to a certain extent, and the speed of water vapor discharge from the concrete roof to the insulation layer can be slowed down; The breathable waterproof membrane is used as the building covering system (hereinafter referred to as waterproof and breathable membrane), which prevents the liquid phase water and vapor phase water from penetrating into the outside of the building, and at the same time, the water vapor of the insulation layer is rapidly discharged. The combined use of the vapor barrier layer and the waterproof and breathable membrane enhances the air tightness and water tightness of the building, solves the problems of moisture and mold, and effectively protects the thermal performance of the enclosure structure, thus truly achieving the purpose of saving energy and effectively discharging the water vapor inside the structure.
At the end of the 1980s, the waterproof and breathable membrane scheme was vigorously promoted in developed countries in Europe and America, and was widely used in residential buildings and public buildings. The waterproof and breathable membrane construction structure was known as "breathing house". The waterproof breathable membrane is laid on the insulation layer to effectively protect the insulation layer. There is no need to pour fine aggregate concrete on the insulation layer. The optimization of the scheme reduces the construction cost. Japan, Malaysia and other countries have also introduced the technology of Germany and the United States, and began to mass produce and apply waterproof and breathable membranes.
In recent years, with the development of building energy conservation in China, new products and technologies have been well applied. In 2006, waterproof and breathable membranes also entered the Chinese market.