Kosteussulkuminen

Kosteussulkuminen, also known as moisture barrier or vapor barrier in English, is a material or layer within a building's construction that is designed to prevent or significantly reduce the passage of water vapor from one area to another. Its primary purpose is to control humidity levels and protect building components from moisture-related damage.

In building construction, temperature differences between interior and exterior environments can cause water vapor to migrate through walls, floors, and ceilings. If this vapor condenses within the building structure, it can lead to mold growth, rot, and a decrease in the thermal insulation's effectiveness. Kosteussulkuminen is typically placed on the warm side of the insulation layer in cold climates to prevent indoor moisture from reaching the colder exterior surfaces where it could condense.

Common materials used for kosteussulkuminen include polyethylene sheeting, aluminum foil, and specialized vapor-retarding paints or membranes. The effectiveness of a kosteussulkuminen is measured by its permeance rating, with lower permeance indicating a greater resistance to water vapor transmission. Proper installation is crucial to ensure the barrier is continuous and sealed, preventing any gaps or holes that could compromise its function. The need for and placement of kosteussulkuminen can vary depending on the climate, building materials, and specific design requirements.