Attic Insulation R38 Vs R49

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Attic insulation r38 vs r49.

Whoa whoa david oswald you ve just entered the domain of the law of diminishing returns. Recently door to door sales representatives for an insulation company offered a free inspection and quote to add additional insulation. Add insulation to attic. Existing 3 4 inches of insulation.

The bottom line is that although you can certainly put r 40 insulation under your slab or r 80 insulation in your walls it may not be the smartest thing to do. Sixty grains even faster. The law of diminishing returns tells me that r49 isn t much better than r39 and r60 probably even more so. Use this insulation savings calculator to measure the financial impact of increasing your insulation performance.

Eere information center 1 877 eere info 1 877 337 3463. 30 grains of black powder will drive that lead ball just fine. R49 to r60 r38 to r49 r25 to r30 and add r5 to r6 insulative wall sheathing beneath the new siding 6 7 8 whenever exterior siding is removed from an uninsulated wood frame wall drill holes in the sheathing and blow insulation into the empty wall cavity before installing the new siding. I have a 6 year old home with about 12 inches r 30 of blown in insulation in the attic.

Our gc says r 38 is what they usually use in this area and that s good enough. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation. Take a look at the bigger picture and see whether you might be better served by reducing the size of the home finding ways to save on water heating appliances and plug loads or. I like our gc but he.

90 grains might be approaching the ma. 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. I ve read it should be r 49 or higher for optimal effectiveness. Get free shipping on qualified r38 r49 insulation or buy online pick up in store today in the building materials department.

Here s what i mean. Wall insulation whenever exterior siding is removed on an.