How To Achieve R 49 In Attic

Evaluate your house s current r value and recommend whether additional r value is needed and appropriate types of insulation.

How to achieve r 49 in attic.

The table opposite suggests r values by zone as indicated in the map of the united states. It also suggests r values when adding insulation to uninsulated or under insulated attics crawl spaces and walls. 2 r 23 batts will just fit inside a 2x12 rafter for r 46. Spray foam insulation r values.

Amongst all of the popular types of insulation currently used by the industy spray foam insulation features the highest r value per inch. Click the button to calculate the approximate r value for this job. Input depth of existing blown in insulation in inches. Obviously if you don t have 17 inches of attic space then you ll have to use some other kind of insulation.

As dana mentioned use a smart vapor retarder. X 24 in 6 pieces 48 sq. 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. 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. For your attic project install r 49 ecotouch insulation. References department of energy.

Achieving greater r values in exterior walls in exterior walls add insulating sheathing to achieve a greater r value in your wall system. Offers exceptional thermal and sound control performance. Then install a sheet membrane for air tightness. Bag meets r 49 attic code requirements with a single batt.