Attic Insulation Requirements

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.

Attic insulation requirements.

Include insulation in the outer walls of the home. Add loose fill insulation to your attic or foil faced batt insulation to your cathedral ceiling. According to the u s. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation.

The recommended level for most attics is to insulate to r 38 or about 10 to 14 inches depending on insulation type. 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. Existing 3 4 inches of insulation. 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.

Pa302 1 ceilings with attic spaces n1102 2 1 r402 2 1. Add insulation to attic. However there is an exception. 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 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. Recommended insulation levels for retrofitting existing wood framed buildings. 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. The 2015 irc requires r 49 insulation for ceilings with attic spaces.

For added energy control and sound deadening.