höyrynvastusluvulla
Höyrynvastusluku, often translated as vapor retarder or vapor barrier, is a material or system designed to control the diffusion of water vapor through building assemblies. Its primary function is to prevent moisture from migrating from warmer, more humid interior environments to colder, drier exterior environments, where it can condense within wall or roof structures. This condensation can lead to a range of problems including mold growth, material degradation, and reduced thermal performance of insulation.
The effectiveness of a vapor retarder is measured by its permeance, which is the rate at which