Application of House Wrap in Building Curtain Wall
The curtain wall has always been the main decoration means for public buildings and the exterior walls of middle and high-end residential buildings. Although the national standard (GB/T21086) on the building curtain wall has put forward requirements about building water tightness, and the water spray test method has been given on appendix D, but in curtain wall structure design, architectural designers still put more attention on the design and calculation of structural strength, cause this is the key factor about residential safety. The less attention paid on building water tightness design and necessary measures makes the curtain wall leakage problems one of the most common ones nowadays.is used to consider structure safety, attaches great importance to the design and structure strength calculation, to prevent leakage of rain curtain wall design and the necessary measures should be taken seriously enough, make leakage building curtain wall is one of the common problems,especially in places with heavier rainfall and stronger wind pressure. In southern coastal areas where typhoon often occur, the curtain wall leakage phenomenon is more common, resulting in insulation failure, wet spots, mildew, etc..Therefore, if the thermal insulation material has certain water absorption rate, it is very necessary to set a waterproof layer between the curtain wall and the thermal insulation layer,in order to make the moisture accumulated inside the insulation layer discharge out in time. The house wrap is an common waterproof layer people often use for waterproof and breathable use.
Waterproof Breather Membrane is made of high performance composite materials.The microporous structure of the fiber staggered has small and uniform aperture. The pore can let the water vapour inside go out freely, but unable to let the condensed water on the membrane penetrate in, thus ensures the building dry (a lack of moisture), and avoids condensation water to cause some problems inside the roof and wall or even damage the interior furniture.
Now lets learn about condensation:
1. The air contains colorless water vapor, which is usually measured by humidity (RH%);
2.The higher the temperature of the air, the more water vapor it contains.
3.When the temperature drops, the air can't control the original water vapor, which will turn to liquid water.
4. The lower the air temperature is, the higher the humidity is. When the humidity reaches 100%, the water vapor condenses into liquid, and the condensation phenomenon occurs.
5. As long as the hot air inside the building volatilizes and contacts the roof and wall with lower temperature, condensation phenomenon will occur;
6. When condensation occurs, water droplets will be formed on the roof or wall surface.Water droplets can be absorbed by the building, which will damage the wall and roof structure, or they will drip and damage the things inside the building.Therefore, the correct design and installation of light steel and wood structure villa contains the house wrap roof membrane.
Precautions for using of house wraps: correct installation is the key to ensure good of waterproof and windproof performance of house wraps.
1. The House Wrap upper side is put outside on the laps, while The House Wrap lower side is put inside on the laps. This kind of lap will successfully let the condensation water drip out of the building by gravity action.
2.the corner waterproofing: installation on corners is very important.Before the corner is fixed with nails, the polymer flashing butyl tape should be adhered in advance, because even if the flashing butyl tape is penetrated by nails, as long as the nails are not pulled out, the perforation is still windproof and windproof.
3. Installation on windows and doors: the house wrap sealing work on windows and doors should be done from bottom to top, higher tapes is installed outside and lower tapes inside;Longitudinal tape outside, transverse tape inside.The corners of the window sill should be adhered with two pieces of flashing butyl tape just at the corner part with a 45° angle in advance, then sealed with flashing butyl tape again on the outside.
The best way to make the inside room clean and comfortable is to install insulation and waterproof breathable membrane. The installation of insulation and waterproof breathable membrane can not only improve the energy saving effect of the building, but also improve the air quality inside the building and reduce the mildew and leakage phenomenon which usually appear in traditional building.Waterproof Membrane is a perfect choice for modern architecture.