Attic Insulation R38 Vs R49

Add insulation to attic.

Attic insulation r38 vs r49.

30 grains of black powder will drive that lead ball just fine. Sixty grains even faster. Eere information center 1 877 eere info 1 877 337 3463. 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.

We re trying to be as environmentally smart as possible and i m not sure who to believe. I have a 6 year old home with about 12 inches r 30 of blown in insulation in the attic. Wall insulation whenever exterior siding is removed on an. Square feet of house or area to be insulated current and desired r value for insulation and type and cost of your energy.

Enter your data into the fields where indicated. 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. Our gc says r 38 is what they usually use in this area and that s good enough.

The law of diminishing returns tells me that r49 isn t much better than r39 and r60 probably even more so. 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. 90 grains might be approaching the ma.

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. Recently door to door sales representatives for an insulation company offered a free inspection and quote to add additional insulation. I like our gc but he.

Whoa whoa david oswald you ve just entered the domain of the law of diminishing returns. We re having our attic blown w insulation.