What is the specific function of waterproof vent and vapor barrier film?

The waterproof vent is generally a layer of functional material on top of the insulation layer. It is also called spunbond polyethylene and polypropylene film on many design drawings. The moisture is discharged to the outside, allowing the insulation layer to remain dry, increasing the insulation function of the building, and making the building more energy-efficient.

The waterproof vapor barrier film is generally used as a vapor barrier layer, which is used in the lower layer of the thermal insulation layer to prevent moisture and vapor, and prevent indoor moisture from penetrating into the thermal insulation layer, which affects the service life of the thermal insulation layer.

Waterproof air barrier membranes and waterproof vents are generally used for waterproofing metal roofs. The differences are:

1. The waterproof vent can be said to be an upgraded version of the air barrier film, which can not only effectively waterproof, but also release water vapor to prevent the metal from rusting.

2. The waterproof and air-proof membrane is very good for waterproofing, but the water vapor in the building structure cannot be volatilized, and the metal roof will definitely rust in the long run.