How To Achieve R 49 In Attic

Click the button to calculate the approximate r value for this job.

How to achieve r 49 in attic. Fortunately attic insulation can be upgraded simply by adding more to achieve the recommended total depth in inches without removing existing insulation. References department of energy. Offers exceptional thermal and sound control performance. Spray foam insulation r values.

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. The table opposite suggests r values by zone as indicated in the map of the united states. Evaluate your house s current r value and recommend whether additional r value is needed and appropriate types of insulation.

This calculator is to be used as an estimating tool only. Achieving greater r values in exterior walls in exterior walls add insulating sheathing to achieve a greater r value in your wall system. You can achieve better thermal performance in your attic by adding an additional layer of insulation. Amongst all of the popular types of insulation currently used by the industy spray foam insulation features the highest r value per inch.

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. Bag meets r 49 attic code requirements with a single batt. Fill available space with roxul comfortbatts. 2 r 23 batts will just fit inside a 2x12 rafter for r 46.

For your attic project install r 49 ecotouch insulation. It also suggests r values when adding insulation to uninsulated or under insulated attics crawl spaces and walls. Then install a sheet membrane for air tightness. If you truly need r 49 that won t work but if that is just a target r 46 is close.