They are available in widths suited to standard spacings of wall studs and attic or floor joists.
R factor for live in attic.
Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation.
Depending on where you live and the part of your home you re insulating walls crawlspace attic etc you ll need a different r value.
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.
Recommended insulation levels for retrofitting existing wood framed buildings.
Loose fill insulation usually made of fiberglass rock wool or cellulose comes in shreds granules or nodules.
Add insulation to attic.
Therefore at least 11 inches of fiberglass or 9 inches of.
Existing 3 4 inches of insulation.
Typical recommendations for exterior walls are r 13 to r 23 while r 30 r 38 and r 49 are common for ceilings and attic spaces.
2x4 walls can hold r 13 or r 15 batts.
Houses in a cold climate should have a minimum of r 49 in the attic which is equivalent to approximately 16 of fiberglass insulation.
2x6 walls can have r 19 or r 21 products.