aurutõkked

Aurutõkked, also known as vapor barriers or vapor retarders, are materials used in building construction to prevent or slow down the diffusion of water vapor from the interior of a building to the exterior. This is particularly important in colder climates where the interior air is warmer and more humid than the exterior air.

The primary function of an aurutõke is to protect the building's structure, especially insulation, from moisture accumulation. When warm, moist indoor air comes into contact with colder building materials, such as studs or sheathing, the water vapor can condense, leading to rot, mold growth, and decreased insulation effectiveness. An aurutõke, typically installed on the warm side of the insulation (usually the interior side in cold climates), creates a barrier that significantly reduces this vapor movement.

Common materials used for aurutõkked include polyethylene sheeting, asphalt-coated kraft paper, and specialized membranes. The choice of material and its proper installation are critical for its effectiveness. Gaps, tears, or improper sealing can allow moist air to bypass the barrier and cause condensation issues.

In some climates, particularly those with high humidity year-round or where cooling is the primary concern, an aurutõke might be installed on the exterior side of the insulation. This is known as an "inverse vapor retarder" and its purpose is to prevent humid outdoor air from entering the wall assembly and condensing on cooler interior surfaces. The specific climate and building science principles dictate the correct placement and type of vapor control strategy.