How Important Is Vapor Barrier In Attic

Because it s nearly impossible to seal penetrations in the ceiling the reality is water vapor will get into the attic.

How important is vapor barrier in attic. Source department of energy. The attic of a building is an important area for insulation and vapor barriers because warm air rises through a building and comes into contact with cold air close to the exterior of the loft space. Adding a second vapor barrier could cause condensation to become trapped in the insulation between the two vapor barriers. A vapor barrier in an attic assembly in a severely cold climate with the absence of an air barrier will likely be ineffective.

A plastic vapor barrier is best installed in a vented attic within climates with over 8 000 heating degree days. The roof is well ventilated with soffit vents and a whirlybird. This acts as a barrier to keep heated moist air from rising up into the attic during cold weather. Ratings are awarded for different types of vapor barriers depending on their effectiveness at retarding the passage of water.

Vapor barriers are a must for protecting your home against the damaging effects of moisture and keep your crawl space dry. On the other hand an air barrier a properly detailed air tight drywall ceiling for example in the absence of a vapor barrier can be effective since it stops the flow of vapor laden air. With a vapor barrier you will be able to significantly reduce this movement of vapor and make your living space more comfortable. I already put vapor barrier and insulated the outside walls.

Climates vapor barriers or more accurately vapor diffusion retarders should be part of a moisture control strategy for a home. Attic vapor barrier detail for cold climates. Large amounts of moisture can reduce the effectiveness of insulation and promote structural damage. Over time this trapped moisture can rot the wood framing in your attic or cause mold and mildew to appear.

In circumstances where conditions inside a home or office are much different than outdoor conditions water vapor is likely to move through wall cavities and can get trapped inside and a well installed vapor barrier is recommended. Going to heat it with a couple of ceramic heaters.