How To Achieve R 49 In Attic

It s been a while since i dealt with insulation but i m pretty sure your gc was talking about the standard fiberglass batting the pink stuff when he said that you would need 17 inches of insulation to reach your required r value of 49.

How to achieve r 49 in attic.

It also suggests r values when adding insulation to uninsulated or under insulated attics crawl spaces and walls. Amongst all of the popular types of insulation currently used by the industy spray foam insulation features the highest r value per inch. X 24 in 6 pieces 48 sq. References department of energy.

Obviously if you don t have 17 inches of attic space then you ll have to use some other kind of insulation. Bag meets r 49 attic code requirements with a single batt. As dana mentioned use a smart vapor retarder. Fill available space with roxul comfortbatts.

Then install a sheet membrane for air tightness. Spray foam insulation r values. If you truly need r 49 that won t work but if that is just a target r 46 is close. You can achieve better thermal performance in your attic by adding an additional layer of insulation.

Fortunately attic insulation can be upgraded simply by adding more to achieve the recommended total depth in inches without removing existing insulation. Input depth of existing blown in insulation in inches. Achieving greater r values in exterior walls in exterior walls add insulating sheathing to achieve a greater r value in your wall system. This calculator is to be used as an estimating tool only.

For your attic project install r 49 ecotouch insulation. For example energy star recommends r 30 for a roof in the southern united states r 38 for the middle of the country and r 49 for the northern part of the country. Evaluate your house s current r value and recommend whether additional r value is needed and appropriate types of insulation. 2 r 23 batts will just fit inside a 2x12 rafter for r 46.