Moisture Vapor Transmission Rate

Moisture vapor transmission rate (MVTR) is a measurement of the rate at which moisture vapor permeates a material. It is expressed in units of grams per square meter per day (g/m2/day). MVTR is an important property to consider when selecting materials for building envelopes, as it can affect the moisture content of the interior space and the potential for mold growth.

Factors Affecting MVTR

Several factors affect the MVTR of a material, including:

  • Material thickness
  • Density
  • Porosity
  • Temperature
  • Relative humidity

Moisture Tests in Houses

Moisture tests are conducted in houses to determine the moisture content of the air or materials. These tests can be used to identify potential moisture problems, such as leaks or condensation, and to assess the risk of mold growth. Several types of moisture tests can be performed, including:

  • Relative humidity tests
  • Quantitative moisture tests
  • Infrared thermography

Importance of MVTR

MVTR is an important property to consider when selecting materials for building envelopes because it can affect the moisture content of the interior space and the potential for mold growth. Materials with a low MVTR can help to keep the interior of a building dry and free of mold, while materials with a high MVTR can allow moisture to enter the building, which can lead to problems such as mold growth, rot, and structural damage.