The recommended level for most attics is to insulate to r 38 or about 10 to 14 inches depending on insulation type.
How deep should attic insulation be.
This allows you to board the attic to use as additional storage space.
Existing 3 4 inches of insulation.
For loose fill read labels.
In temperate coastal areas such as zone 3 attic insulation of at least r30 up to a maximum of r60 is recommended.
First things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of insulation.
For loose fill cellulose this translates to a total depth ranging from 8 inches.
Recommended insulation levels for retrofitting existing wood framed buildings.
Add insulation to attic.
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.
The insulation in your attic should be at least 12 thick.
You can achieve better thermal performance in your attic by adding an.
Fibreglass insulation will need to be laid to a depth of anything between 8 inches and a foot.
The thicker the better.
Around a 4 inch depth of insulation will be required with the highest performing spray foam.
To insulate to r value 50 with an r value of 3 5 per inch you will need 50 divided by 3 5 or about 14.
Achieving greater r values in attics.
Inspecting your attic insulation.
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.
Calculating thickness divide the desired r value by the r value per inch stated on the label.
For batts or rolls calculate the number based on the width and length of the product you re using.
If your attic insulation is only a few inches thick or if you can see the ceiling joists you re wasting money on your heating and cooling bills.
Measure your attic s square footage.
It is not uncommon to see 15 to 20 of insulation in a well insulated attic.