What is Blown in Insulation?

Blown In Insulation means blowing or spraying insulation products into wall cavities, floors, and attics. Methods are different, depending on the form of insulation selected.

Loose-Fill Fiberglass

In its loose-fill form, fiberglass is made from glass that is blown into fibers. It is possible to install it by using a blowing machine. This product is suitable for attics and wall cavities and can combat a lot of insulation enemies like mildew, fungus, and moisture. But many fiberglass products include recycled glass and that loose-fill fiberglass can leave floating particles in the area where it is going to be installed. And this is not a good thing.

So, to prevent this thing, it’s better to contain the fiberglass with membranes or using a netting system. Netted cavities are made with fire-resistant, odorless, and chemical-free fiberglass and provide an R-value of 4.2 per inch.

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There are three main types of blown-in cellulose insulation that are used in residential applications: loose fill, stabilized, and wall-cavity spray.

When you are going to install insulation in an existing closed wall or in an attic, it likely will be blow-in cellulose insulation. While insulating the attic, other alternatives are fiberglass batts or blown-in fiberglass. But with enclosed walls, blowing in loose-fill cellulose insulation is the most

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Rock Wool

Also called “mineral wool,” this type of blown-in insulation is made from blast furnace slag. The slag is heated, combined with other minerals, and then spun into an airy product that resembles the texture of raw sheep’s wool. Has an R-Value of R-3.3 per inch, but it is much more expensive than either loose-fill fiberglass or cellulose. Despite its high price point, it is excellent fire resistance, and it is used by many.

What Is Loose-Fill Cellulose Insulation?

Cellulose insulation is a product made of wood. It is used to fill empty spaces of a house to prevent as much as it can the transmission of heat or cold. Cellulose insulation is thick, dense, and clumpy. The shape and size of this product can fit in enclosed areas such as walls and wires and ducts.

Commercial cellulose insulations are made from wood, specifically, paper: recycled newspapers, cardboard, office paper, and other common waste paper products. This is the reason that cellulose insulation is considered an eco-friendly home product.

Cellulose Insulation Advantages

There are a number of advantages to using cellulose insulation over other types:

  • Loose-fill cellulose insulation can settle around in the spaces in walls and attics.
  • Loose-fill cellulose is inexpensive, yet still has an R-value of about 3.5 per inch of thickness, compared to fiberglass’ R-value between R3 to R4 per inch.
  • When the walls are already finished, injecting loose-fill cellulose insulation is one of the few ways to insulate that area. One alternative is to pull down the drywall and use fiberglass batts. 
  • Cellulose insulation combat insects and vermin.

Cellulose Insulation Disadvantages

There are also a few drawbacks to cellulose insulation:

Earlier we said that the insulation during the time will settle down but can pack down and form pockets above the settled areas. These pockets will become thermal bridges. This way these bridges can transmit heat or cold into the house. in attics But this is less problematic in the attic for two reasons. First, attic spaces can be overfilled. Second, when cellulose insulation in attics settles, no empty spaces are formed. Moisture dramatically cuts R-value and may form mold and mildew. Rigid or sprayed-in foam stands up better against moisture.

How Cellulose Insulation Is Blown Into the Home?

The most common product that a lot of people will use is called loose-fill cellulose insulation. This is different from another type of cellulose insulation, which is spray foam. Spray foam sticks to the wall. With loose-fill insulation the cellulose is dry.

To fill finished walls, holes are drilled in the plaster or drywall for the access of the blower nozzle. For attics, cellulose insulation is blown in parallel to the joists. 

The installation process for dry cellulose insulation looks like this:

  1. Densely packed pieces of cellulose are fed into the hopper of an insulation blower powered by an electric motor. The hopper has rotating teeth at the bottom and that where the cellulose comes out.
  2. The cellulose is blown into the attic or walls through long, flexible tubes that are connected to the machine that contains the product.
  3. The cavities or blanket existing insulation can be filled with cellulose. There is no need to pressure the cellulose; it will settle over time.

Is Cellulose Insulation Considered Green?

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With cellulose, eco-friendliness is a debatable issue. On the one hand, it may be considered green because it uses up to 85 percent recycled materials. However, the remaining 15 percent, includes the borate treatment and is less-than-green because it is a chemical treatment.

So the green advantage of cellulose insulation may be less significant than it is sometimes said.

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