Once determined subtract the current r value from your desired r value to get the r value you need to add.
Desired r value for attic.
The recommended r value for attic floor insulation for this house is r 38.
R value is a measure of insulation s ability to resist heat traveling through it.
This zone s recommended r value for an uninsulated attic is r30 to r60.
The homeowner could then check table 1 to find several choices.
Your home s age if your home is more than 10 year old you likely need more insulation.
When determining how much insulation you need don t guesstimate calculate.
Find the recommended r value for attic insulation in your area.
Be sure to carefully follow the installation instructions to get the desired insulation r value.
This effect is most important if the new insulation is more dense than the old insulation.
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.
An attic with too little insulation will waste energy and money in both winter and summer.
There are many ways to retrofit a home with fiberglass and.
Measure the length and width of the attic then multiply those numbers to get the total square footage.
Input length width and desired r value of the area to be insulated.
This calculator is to be used as an estimating tool only.
The higher the r value the greater the insulation performance.
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.
You will need a higher r value of insulation if you live in the northeast than if you live in southern california.
Insulation level are specified by r value.
Of inches to determine your existing r value.
R value measures how well certain building insulation materials can resist heat.
Recommended home insulation r values.
An r value of 40 to 50 rsi seven to 8 8 is recommended for attic insulation in most parts of u s.
It is generally better to insulate to a higher r value than the minimum recommended level.
Subtract that amount from the desired r value for your home s zone to.
Determining your attic insulation needs.
The higher the r value the better the thermal performance of the insulation.
Know exactly how much you need with our project calculators.
Calculate the square footage of the attic you re insulating.
