House Wrap Construction Notice and How to Identify House Wraps?
House Wrap is mainly applied in the field of construction in steel structure and wood structure. House Wrap is a kind of high-tech microporous membrane, which is not punctured hole made by mechanical means but high tech uniform micro pores. The size of the micropore can make the water vapor molecules pass through smoothly, but do not let the a lot larger water molecules to leak back again, so as to achieve the waterproof and breathable performance.
1. The Installation Instruction of PANZHU Waterproof Membrane
After choosing a good Waterproof Membrane, we will care more about installation.In the process of construction, try to avoid penetration and opening on the waterproof membrane, and try to ensure the integrity of the waterproof membrane.If openings or penetrations must be made, they should be sealed with PANZHU flashing butyl tape.
Because the waterproof membrane has no obvious flame retardant effect, it is necessary to avoid welding of curtain wall project connection. The operation with flame(including welding) should be arranged before the construction of waterproof membrane. It is strictly forbidden to conduct operation with fire (including electric welding) near the waterproof membrane.
When installing waterproof membrane, choose the method according to the actual situation. Fix the waterproof membrane and insulation with insulation screws, seal the screw cap with flashing butyl tape, the flashing tape should be much larger than the screw caps.
(For steel structure installation)
Clean the dust and oil on the corner steel brackets before construction to ensure the corner steel brackets clean and ensure the bonding effect of the corner steel brackets and Breathable Membrane.When the corner steel brackets passing through the Breathable Membrane, the integrity of the Breathable Membrane should be guaranteed as far as possible. The curve flashing will cover the surrounding of corner steel brackets and Breathable Membrane. At least 2 cm flashing butyl tape should be pasted on the corner steel brackets and 2cm on the Breathable Membrane to flash the seam of them. The curve flashing upon them should be flashed again with flashing butyl tape to ensure the waterproof of the membrane.
To flash the breathable membrane with the window frame and door frame, flashing butyl tape should be used. Cut a piece of flashing tape about 5 inches and stick it perpendicular to the wall at the bottom corners of the window and extend at least 2 inches outside the wall(do not extend to the inside wall). Press it firmly to prevent air and water penetration.Installation sequence: bottom of the door window frame → lower corner of the door window frame → jamb frame of the door window frame → upper corner of the door window frame → upper sill of the door window frame → seal.
During roofing construction, the laying of waterproof Roof Membrane should be along the direction of the roof with the lap length of 10cm. The higher membrane should be placed outside on the lap. When the high-strength aluminum alloy bracket of the roof passes through the waterproof Roof Membrane, the seams between the aluminum alloy bracket and waterproof Roof Membrane should be sealed by a circle of flashing butyl tape.In addition, the waterproof Roof Membrane should not be exposed to UV for a long time, so the exterior decoration project should be completed as soon as possible.
2. How to identify the true and false waterproof roof membrane
Test items: a. temperature resistance b. water vapor transmission rate (i.e. air permeability) c. hydrostatic water pressure d. aging resistance
True waterproof roof membrane is not composite with glue, so the temperature resistance is -40 to 100 degrees centigrade(COMFORMS TO EU CE standard, American ASTM standard).True waterproof roof membrane is not made by spraying polyethylene or TPO on the membrane, so the air permeability should be more than 1500g/ m2/24h. The membrane made by spaying polyethylene or TPO on is basically airtight.For hydrostatic water pressure test, the hydrostatic water pressure of thin waterproof roof membrane should be at least 1.5 meters and thick True waterproof roof membrane should be at least 2 meters.Anti-aging is necessary, because PP material is easy to aging under ultraviolet light, some fake waterproof roof membrane is easy to decompose in the construction process.
2.Simple DIY detection
On both sides of the true air barrier, there are obvious pressure point. That is because the production process is through hot pressing method. Please note that the pressure point is not the points on the non-woven fabric itself, but the obvious hot pressing point. Tear apart the air barrier, there are three layers. The middle layer of the air barrier should be a milky white very soft layer for the function of waterproof and breathable. There are also pressure point on this layer. In addition, press the air barrier and feel, there shouldn’t any sticky feel. If there is, this membrane is made by hot melt adhesive. This kind of membrane will soon have bubble inside and turned into several separated layers.
In recent years, as the governments of various countries pay more and more attention to building energy saving, the energy saving and environmental protection requirements are improved day by day. The waterproof breathable air barrier is becoming more and more popular around the world.