Do I need a vapor barrier with blown in cellulose?
With Modern’s Cellulose insulation, a vapor barrier is not recommended except in very cold weather or high moisture areas such as spas or pool buildings. However, many building codes do require an Air barrier or Vapor retarder to be installed. Cellulose insulation has a high density compared to fiberglass.
Where should a vapor barrier be installed when using blown in insulation?
Or more generally, we place a vapor barrier on the “warm side” of a wall (or ceiling or floor) in order to prevent moisture from moving into and accumulating in the building cavity. In northern climates invariably that means the vapor barrier goes inside the building.
Is blown cellulose an air barrier?
Dense pack cellulose and dense pack fiberglass are not air barrier materials, and they do not result in air barrier assemblies. Although, with respect to air barrier assemblies, they sometimes come pretty close.
Is blown in cellulose insulation safe?
Is Cellulose Insulation Safe for Your Home? Despite being made from paper, cellulose insulation does not make your home vulnerable to fire. Cellulose insulation is treated with fire retardants such as ammonium sulfate, borax, and boric acid to meet all governmental safety requirements.
Do you need a vapor barrier in attic?
All attics — vented or unvented — should have an air barrier (a properly detailed airtight drywall ceiling, for example) regardless of climate. Omitting a ceiling vapor barrier by arguing that “you have to let the moisture escape” or “because the house has to breathe out the top” is actually correct, in a way.
What happens if cellulose insulation gets wet?
How Water Inundation Impacts Cellulose Insulation. Cellulose is a loose-fill product. The material is designed to fill space with the “fluff” of the fibers to prevent voids and air pockets. When the fibers become wet to an excessive level, their weight increases, and the material will slowly compress and settle.
How long does blown-in cellulose insulation last?
20 to 30 years
Cellulose Insulation The typical lifespan is 20 to 30 years, with degradation beginning as early as 15 years after installation. As with other types of insulation, severe weather or outside interference can reduce the lifespan.
How long does blown in cellulose insulation last?
How important is vapor barrier in attic?
Vapor barriers are used to prevent that moisture from getting into enclosed areas where you don’t want it, because once it gets in there, if it can’t escape it can do a lot of damage. For that reason, batt insulation often comes with a vapor barrier on one side.
Why do we use blown cellulose insulation?
The type of blown cellulose insulation we use is made from recycled newspaper. And now, the reasons we use blown cellulose insulation in our custom homes: Stops Air Leaks: According to the Cellulose Insulation Manufacturers Association, blown cellulose insulation is 30% to 40% more effective at stopping air infiltration than a similar house insulated with fiberglass batts installed in the typical manner.
How do you calculate blown in insulation?
The standard calculation given by manufacturers for blown insulation is the number of bags per 1,000 square feet required to achieve a desired R-value. Depending on the manufacturer, this number ranges from around 12 to 15 bags per 1,000 square feet for an R-value of 26.
How much does it cost to blow in insulation?
Blown-In Insulation Cost Per Square Foot. Pre-installation prices for the most common types of blown-in insulation are $0.83 per square foot for Cellulose, and $0.91 per square foot for Fiberglass.
What is blow in cellulose?
Blown in cellulose insulation is made mostly from shredded newspaper and mixed with a variety of chemicals (up to 25% by weight) to reduce its flammibility. Fiberglass insulation is made by jetting molten glass through tiny heated holes in a high-speed stream.