## How deep should blown in insulation be in an attic?

about 10 to 14 inches

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

## How deep is R38 blown insulation?

12.75”

Fiberglass Chart

R-Value | Thickness | Bags / 1000 Sq Ft |
---|---|---|

R49 | 16.25” | 22.6 |

R44 | 14.75” | 20.1 |

R38 | 12.75” | 16.8 |

R30 | 10.25” | 13.0 |

**How thick should your blown in insulation be?**

When blown into attics and wall spaces, loose-fill fiberglass offers an average R-2.5 thermal value per inch (the higher the number, the greater the insulating effect). You’d need a thickness of about 7.5 inches of insulation to match the insulating value of a batt of R-19 insulation (R-19 is a common batt value).

**How many inches of blown insulation is R60?**

R 60: Thickness that oscillates between 19 and 22 inches. R 70: Thickness that oscillates between 22 and 25 inches.

### How thick is R60 attic insulation?

17 inches

The average recommended level is 17 inches of R60. How much insulation in attic for Zones 5-7? In Zone 5, the average minimum requirement for attic insulation is 11 inches of R38 fill. The average recommended level is 17 inches of R60.

### How thick is R60 blown insulation?

R 60: Thickness that oscillates between 19 and 22 inches.

**How many inches is r40 insulation?**

Johns Manville R-40 Fiberglass Batt Insulation (24-in x 48-in)

**How thick is r50 blown insulation?**

between 15 and 19 inches

R 50: Thickness that oscillates between 15 and 19 inches. R 60: Thickness that oscillates between 19 and 22 inches. R 70: Thickness that oscillates between 22 and 25 inches.

## How many inches of cellulose is R60?

The average recommended level is 17 inches of R60. In Zone 4, the average minimum requirement for attic insulation is 11 inches of R38 fill. The average recommended level is 17 inches of R60.

## What is the R-value of 6 inches of blown-in insulation?

If you will be installing a rigid board that has an R-value of 6.5, and you live in a very cold area requiring six inches of insulation, the total R-value will be 6.5 x 6 or (6.5+6.5+6.5+6.5+6.5+6.5), totaling to an R-value of 39.

**Can you put rolled insulation over blown insulation attic?**

“Faced” insulation should not be placed on top of existing insulation in the attic. Any new batt or roll insulation installed over existing insulation in the attic needs to be without a vapor retarder (face). The vapor retarder on top of or between layers of insulation can trap moisture.