Attic Insulation Requirements

Find your zone on the map and then use the chart to determine the level of insulation you need to properly insulate your attic walls floors and crawlspaces.

Attic insulation requirements.

R 38 shall be deemed to satisfy the requirement for r 49 wherever the full height of uncompressed r 38 insulation extends over the wall top plate at the eaves. Ventilation openings having a least dimension larger than 1 4 inch 6 4 mm shall be provided with corrosion resistant wire cloth screening hardware cloth perforated vinyl or similar material with openings having a least dimension of 1 16 inch 1 6 mm minimum and 1 4 inch 6 4 mm maximum. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation. Department of energy it s recommended that attics have an r 38 to r 49 or about 12 to 15 of fiberglass or cellulose insulation.

Use unfaced insulation when adding more insulation to an attic that already has some insulation laying the rolls or batts at right angles to the floor joists. Add insulation to attic. However there is an exception. Add loose fill insulation to your attic or foil faced batt insulation to your cathedral ceiling.

1102 2 1 ceilings with attic spaces when section 1102 1 would require r 38 in the ceiling r 30 shall be deemed to satisfy the requirement for r 38 wherever the full height of uncompressed r 30 insulation extends over the wall top plate at the eaves. Add the right kind of insulation when adding additional insulation you do not have to use the same type of insulation that currently exists in your attic. Existing 3 4 inches of insulation. Pa302 1 ceilings with attic spaces n1102 2 1 r402 2 1.

Your attic should have a certain amount of insulation in it and the recommended level of insulation for your attic is dependent on where you live. The recommended level for most attics is to insulate to r 38 or about 10 to 14 inches depending on insulation type. If your insulation doesn t measure up and you need more installation can be done as a weekend diy project or you can call a professional installer to handle the job. The 2015 irc requires r 49 insulation for ceilings with attic spaces.

Include insulation in the outer walls of the home.