Attic Insulation R38 Vs R49

The law of diminishing returns tells me that r49 isn t much better than r39 and r60 probably even more so.

Attic insulation r38 vs r49.

Whoa whoa david oswald you ve just entered the domain of the law of diminishing returns. 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 ve read it should be r 49 or higher for optimal effectiveness. 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.

Recently door to door sales representatives for an insulation company offered a free inspection and quote to add additional insulation. 30 grains of black powder will drive that lead ball just fine. 90 grains might be approaching the ma. Sixty grains even faster.

Eere information center 1 877 eere info 1 877 337 3463. I like our gc but he. 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. 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.

Here s what i mean. Existing 3 4 inches of insulation. 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.

We re having our attic blown w insulation. Add insulation to attic. Wall insulation whenever exterior siding is removed on an. I have a 6 year old home with about 12 inches r 30 of blown in insulation in the attic.

Enter your data into the fields where indicated. We re trying to be as environmentally smart as possible and i m not sure who to believe.