Characteristics of water
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Water is omnipresent, it through wind pressure, convection, impact, adhesion, capillary and other forces, gradually infiltrate the interior of the building, and the infiltration process is not easy to detect from the surface. In other words, to find the cause of water leakage requires an "internal" analysis in order to give the right medicine.
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Pressure change of water and steam
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Once the water penetrates into the building, in a limited space, such as the sun, generate heat, form water vapor, these water vapor produce a large amount of pressure enough to destroy the original waterproof layer, and even the surface decoration and materials (such as paint falling off, wallpaper moldy, tile bulking up, wood floor expansion) the changes in the middle are: The water in 1mole is 18cc and the water vapor in 1mole is 22.4 liters =2400 cc. In other words, if all 1 unit of water becomes water vapor, 1240 times of pressure will be generated in the limited space inside the building. The destructive force of this pressure is too terrible, so we often find that after the construction of waterproof glue, the water in 1mole will become more and more powerful. Soon the whole thing flaked off.
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Waterproofing must be done on a solid body
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The interface with the waterproof material must be free of swelling, sand, honeycomb, wood. Scraps of paper. Sludge, small stones, can not be done on the loose and unstable surface body, the reason is poor adhesion, coupled with solar ultraviolet damage, the building itself thermal expansion and contraction, as well as water vapor pressure damage, easy to cause waterproof layer aging, failure.
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Positive waterproofing is better than negative waterproofing
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If the roof is waterproof, it should be done directly on the surface of the roof, the wall waterproof should be done directly on the external wall, the water leakage of the water tank should be done directly on the inner layer of the water tank, and the bathtub and tile should be knocked off and the waterproof should be done again. Why, because the pressure of water will spread to other places, the dead corner of the house is not easy to construct, the advantages said here are relatively comparative, rather than, because with the development of science and technology, there are people on the market to introduce negative construction of waterproof materials, so no choice, should be adopted positive waterproof construction.