How many inches of blown fiberglass insulation is r38?

Asked By: Malick Alferiev | Last Updated: 12th February, 2020
Category: home and garden indoor environmental quality
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Cellulose Blown in Attic Insulation
R-Value Minimum Thickness Bags per 1000 Sq Ft
R49 15” 75.2
R44 13.4” 66.2
R38 11.6” 55.5
R30 9.3” 42.7

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In this regard, how many inches of insulation is r38?

An R-38 fiberglass batt should be approximately 12 inches thick, while the thickness of cellulose insulation of a finished, fitted product will larger.

Likewise, what is the R value of 12 inches of blown insulation?

R-value of Materials and Depths
Material R-value/in 12"
Fiberglass blown (attic) 2.2 - 4.3 26.4 - 51.6
Fiberglass blown (wall) 3.7 - 4.3 44.4 - 51.6
Mineral Wool (batt) 3.1 - 3.4 37.2 - 40.8

Likewise, how many inches of blown insulation is r40?

Blown and batt insulation have different r-values based on depth. R-25 is approx. 7 inches of blown insulation R-40 is 12 inches of blown insulation.

How many inches of blown fiberglass insulation is r60?

In temperate coastal areas such as Zone 3, attic insulation of at least R30 up to a maximum of R60 is recommended. For loose-fill cellulose, this translates to a total depth ranging from 8 inches up to 16 inches.

33 Related Question Answers Found

Can you put too much insulation in your attic?

But there may be a theoretical point of “too much.” If a home is over-insulated and is too tightly sealed, moisture can get trapped inside. Without proper ventilation, a home can build up too much moisture, especially in the attic (warm air rises), which can cause mold problems and, overall, lower indoor air quality.

How many inches of insulation should you have in your attic?

The recommended level for most attics is to insulate to R-38 or about 10 to 14 inches, depending on insulation type.

What is the thickness of r38 batt insulation?

10¼ ” thick, R-38C EcoTouch® Thermal Batt insulation prevents moisture damage and help assure long roof life by providing 1" of ventilation air space between the insulation and roof deck.

What is cheaper blown in insulation or fiberglass?

Fiberglass batts, however, are less expensive, costing on average $0.30 to $0.40 a square foot for 6 inches of insulation. Installation costs for blown-in insulation costs around $2 a square foot, where installation costs for batts is around $1 a square foot.

What is the best type of attic insulation?

1. Loose fill
  • Fiberglass.
  • Cellulose.
  • Mineral wool. R-value per inch: 3.0–3.3.
  • They work best for: Attics with standard joist spacing, especially those with no insulation.
  • Fiberglass. R-value per inch: 2.9–4.3.
  • Cellulose. R-value per inch: 3.7–3.8.
  • Mineral wool. R-value per inch: 3.0–3.3.
  • Cotton. R-value per inch: 3.7–3.8.

How many inches is r30 insulation?

For future reference, here is the cavity depth you need for some common insulation r-values: 3.5 inches --- R13. 6 inches --- R19. 9 inches --- R30.

Does doubling the insulation increase the R value?

Doubling the thickness of insulation will double the insulation's R-value, cutting heat loss in half. The energy saved per year by doubling insulation from R-10 to R-20, however, will be considerably more than the energy saved by doubling insulation from R-20 to R-40, because of the law of diminishing returns.

How do I know if my insulation is blown?

Cellulose blow-in insulation is constructed out of recycled paper. To determine how much cellulose insulation you need, take the square footage of the space and divide it by either the depth or the desired R-value. Fiberglass blow-in insulation is essentially made up of spun fibers from recycled molten glass.

Is blown insulation better than rolled?

As you can see, both rolled insulation and blown-in insulation are good options; however, blown-in insulation does have a few more advantages going for it, including ease-of-use and the ability to insulate hard to reach areas.

What is blown in insulation made of?

There are three general types of blown insulation materials currently available: fiberglass, cellulose and rock wool. Fiberglass loose-fill insulation is made glass and sand that are spun or “blown” into fibers. This type of insulation is great for wall cavities and attics.

How many inches is r19 insulation?

If your attic has fiberglass insulation batts or blankets, figure that about 4 inches of the material is about R-11, 6 inches about R-19, 8 inches is about R-26, and 10 inches gives an insulation value of about R-30.

Which insulation has the highest R value?

Vacuum insulated panels have the highest R-value, approximately R-45 (in U.S. units) per inch; aerogel has the next highest R-value (about R-10 to R-30 per inch), followed by polyurethane (PUR) and phenolic foam insulations with R-7 per inch.

What is the R value of blown in insulation?

Here are the R-values per inch of the most common types of insulation: Fiberglass (blown): 2.2 – 2.9. Fiberglass (batts): 2.9 – 3.8. Cellulose (blown): 3.1 – 3.8.

How do I choose attic insulation?

The higher the R-value, the more effective an insulating material is. Your home's R-value score will guide you toward the type of insulation you need. In general, an attic's R-value should be between R-30 and R-49. In particularly cold climates, you might go up to R-60.

What is the R value of aluminum foil?

However, that small change in emissivity brings the total R-value down to R-8.17. Now suppose this product is an aluminum foil that sees some water. According to ASHRAE, when just a little condensation is visible on aluminum foil, the emissivity can reach 0.2 to 0.3, which would decrease that R-value down to R-3.86.

Is spray foam insulation toxic?

Spray Foam Insulation Health Issues
Exposure to spray foam in an indoor environment can not only be hazardous to human health but it can also be dangerous to the environment. These health issues can include lung damage, asthma, sensitization, respiratory and breathing problems, and even skin and eye irritation.