Vapor barrier

From WikiMD.com Medical Encyclopedia

(Redirected from Moisture barrier)

Vapor Barrier[edit | edit source]

A vapor barrier is a material used in building construction to resist moisture diffusion through walls, ceilings, and floors. The primary purpose of a vapor barrier is to prevent moisture from entering the building envelope, which can lead to mold growth, structural damage, and reduced insulation effectiveness.

A typical vapor barrier installation.

Function[edit | edit source]

Vapor barriers are designed to limit the movement of water vapor through the building envelope. They are typically installed on the warm side of the insulation in a building, which is the side closest to the interior of the building in cold climates. This placement helps to prevent condensation from forming within the wall cavity, which can occur when warm, moist air from the interior meets the cooler air within the wall.

Materials[edit | edit source]

Common materials used for vapor barriers include polyethylene plastic sheeting, aluminum foil, and specialized vapor-retardant paints. The choice of material depends on the specific requirements of the building project, including climate, building design, and local building codes.

Fiberglass insulation with a vapor barrier.

Installation[edit | edit source]

Proper installation of a vapor barrier is crucial to its effectiveness. It must be continuous and free of gaps or tears. Seams should be overlapped and sealed with appropriate tape or sealant. In some cases, vapor barriers are integrated into other building materials, such as insulation batts with a vapor-retardant facing.

Considerations[edit | edit source]

The use of vapor barriers is not always necessary or beneficial in all climates. In some warm, humid climates, vapor barriers can trap moisture within the building envelope, leading to problems rather than preventing them. It is important to consider the specific climate and building conditions when deciding whether to use a vapor barrier.

Related Pages[edit | edit source]

References[edit | edit source]

  • "Vapor Barriers: A Guide to Understanding Moisture Control." Building Science Corporation. Retrieved from [1].
  • "Moisture Control Handbook: Principles and Practices for Residential and Small Commercial Buildings." John Wiley & Sons.
Replacing a damaged vapor barrier.
WikiMD
Navigation: Wellness - Encyclopedia - Health topics - Disease Index‏‎ - Drugs - World Directory - Gray's Anatomy - Keto diet - Recipes

Search WikiMD

Ad.Tired of being Overweight? Try W8MD's physician weight loss program.
Semaglutide (Ozempic / Wegovy and Tirzepatide (Mounjaro / Zepbound) available.
Advertise on WikiMD

WikiMD's Wellness Encyclopedia

Let Food Be Thy Medicine
Medicine Thy Food - Hippocrates

Medical Disclaimer: WikiMD is not a substitute for professional medical advice. The information on WikiMD is provided as an information resource only, may be incorrect, outdated or misleading, and is not to be used or relied on for any diagnostic or treatment purposes. Please consult your health care provider before making any healthcare decisions or for guidance about a specific medical condition. WikiMD expressly disclaims responsibility, and shall have no liability, for any damages, loss, injury, or liability whatsoever suffered as a result of your reliance on the information contained in this site. By visiting this site you agree to the foregoing terms and conditions, which may from time to time be changed or supplemented by WikiMD. If you do not agree to the foregoing terms and conditions, you should not enter or use this site. See full disclaimer.
Credits:Most images are courtesy of Wikimedia commons, and templates, categories Wikipedia, licensed under CC BY SA or similar.

Contributors: Prab R. Tumpati, MD