An attic with too little insulation will waste energy and money in both winter and summer.
Desired r value for attic.
If the existing attic floor insulation has an r 11 insulation value then an additional r 27 would be needed to bring the attic floor insulation up to the level recommended for that house.
R value is a measure of insulation s ability to resist heat traveling through it.
R value measures how well certain building insulation materials can resist heat.
Instructions on the product where current r value is listed will guide you through estimating the number of packages to buy based on the number of square feet you re insulating and the desired r value.
Determining your attic insulation needs.
Once determined subtract the current r value from your desired r value to get the r value you need to add.
Subtract that amount from the desired r value for your home s zone to.
Be sure to carefully follow the installation instructions to get the desired insulation r value.
The higher the r value the better the thermal performance of the insulation.
The homeowner could then check table 1 to find several choices.
Recommended home insulation r values.
Where you live different climates require different insulation r values.
Click the button to calculate the depth in inches and pounds of total insulation required for this job.
Of inches to determine your existing r value.
Measure the length and width of the attic then multiply those numbers to get the total square footage.
An r value of 40 to 50 rsi seven to 8 8 is recommended for attic insulation in most parts of u s.
When determining how much insulation you need don t guesstimate calculate.
The recommended r value for attic floor insulation for this house is r 38.
This zone s recommended r value for an uninsulated attic is r30 to r60.
You can compensate for this stacking effect and achieve the desired total r value by adding about one extra inch of insulation if the old insulation is fiber glass or about 1 2 inch if the old insulation is rock wool or cellulose.
It is generally better to insulate to a higher r value than the minimum recommended level.
Input length width and desired r value of the area to be insulated.
This calculator is to be used as an estimating tool only.
You will need a higher r value of insulation if you live in the northeast than if you live in southern california.
This effect is most important if the new insulation is more dense than the old insulation.
Calculate the square footage of the attic you re insulating.
The higher the r value the greater the insulation performance.
There are many ways to retrofit a home with fiberglass and.
Your home s age if your home is more than 10 year old you likely need more insulation.
