How Much Is Enough Attic Insulation

Having enough insulation in your attic is one of the best ways to save energy on both heating and cooling your home.

How much is enough attic insulation.

The higher the r value the better the thermal performance of the insulation. For example if you install r 19 fiberglass batts in 2x6 frame walls with the studs 16 inches on center double top plates and other elements of standard framing the actual r value of the whole wall with the r 19 insulation will be about r 15. To find out if you have enough insulation in your attic measure the thickness of the insulation from top to bottom using a ruler. First off you should know that insulating your attic isn t cheap.

If your attic insulation covers your joists and is distributed evenly you probably have enough. Add the right kind of insulation. The recommended level for most attics is to insulate to r 38 or about 10 to 14 inches depending on insulation type. Spray foam while the most expensive is best for noise reduction and new construction.

Use our roll insulation calculator to estimate the amount of wall insulation crawlspace insulation or attic insulation you need for your project. These recommendations are for true r values not the nominal values listed on insulation packaging. How well a particular insulation works is expressed by the r value which ranges from 2 0 to 8 0 per inch of insulation. Blown in insulation is the least expensive option and ideal for older attics.

If it is less than r 30 which is to say 11 inches of fiber glass rock wool or 8 inches of cellulose then you may want to add more. It can cost anywhere from 1 700 to 2 100 or between 1 50 and 3 50 per foot to insulate an attic depending on what insulation material you choose. Energy information administration predicts that this. The higher the r value the better job the insulation does at preventing the transfer of heat.

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. Check the chart below as a down and dirty guide of your existing r value. How much should i add. Insulation levels are specified by r value.