Vapor Barriers or Vapor Retarders | Department of Energy
In most U.S. climates, vapor barriers, or -- more accurately -- vapor diffusion retarders (vapor retarders), should be part of a moisture control strategy for a home. A vapor retarder is a material that reduces the rate at which water vapor can move through a material.
Vapor Barriers and Vapor Retarders — What’s the Difference?
A vapor barrier is used during the construction of a building to prevent moisture damage to the building’s fabric. Now, a vapor retarder is defined by the International Residential Code (IRC) as “a vapor-resistant material, membrane, or covering with a perm rating of 1 or less.”
Understanding Moisture Barriers - This Old House
2024年8月28日 · A moisture barrier, also called a vapor barrier or vapor retarder, is a material that stops water and moisture from passing through walls, floors, and other parts of a building. These barriers can come in different forms, like sheets, coatings, and membranes, and they’re categorized based on their permeability—how much moisture they allow ...
Vapor barrier - Wikipedia
A vapor barrier (or vapour barrier) is any material used for damp proofing, typically a plastic or foil sheet, that resists diffusion of moisture through the wall, floor, ceiling, or roof assemblies of buildings and of packaging to prevent interstitial condensation.
BSD-106: Understanding Vapor Barriers | buildingscience.com
2011年4月15日 · Vapor Retarder*: The element that is designed and installed in an assembly to retard the movement of water by vapor diffusion. * taken somewhat from ASHRAE Fundamentals 2001, Chapter 23. The unit of measurement typically used in characterizing the water vapor permeance of materials is the “perm.”
Vapor Barriers vs. Vapor Retarders - Fine Homebuilding
The International Residential Code (IRC) defines a vapor retarder as a vapor-resistant material, membrane, or covering with a perm rating of 1 or less. However, the 2007 IRC supplement recognizes some materials that have ratings of 1 perm and higher as vapor retarders.
Moisture Control | Vapor Retarders, Residential, Installing
A vapor retarder is defined as a material or system that adequately retards the transmission of water vapor under specific conditions. Building occupants, certain appliances, plants, and plumbing equipment generate moisture that is carried in the air as vapor.
Vapor Barriers vs. Vapor Retarders – What’s the Difference?
2023年7月14日 · A vapor retarder is defined as a layer with a permeance greater than 0.1 perm but less than or equal to 1 perm. This includes materials such as materials as polyethylene sheeting, aluminum foil, kraft paper facing, and vapor-retarding paint. Can a vapor barrier act as a Class-I vapor retarder?
Vapor Barriers | Building Science Education
A vapor barrier, also called a vapor retarder, is a layer in the building envelope that prevents water vapor from entering the wall cavity. There are three different classes of vapor barriers. The class of vapor required depends on the climate zone and cladding type.
Vapor Retarder Frequently Asked Questions - GAF
2021年6月1日 · What is a vapor retarder? It is a material that, depending on its exact specification and correct installation, blocks or slows down the transmission of moisture from one side to the other. Vapor retarders can be coatings, boards with taped joints, or membranes.