Here are the r values per inch of the most common types of insulation.
Blown attic insulation r value per inch.
R value of insulation by type.
This calculator is to be used as an estimating tool only.
Therefore a three inch thick board has an r value of 3.
This calculator is to be used as an estimating tool only.
As a benchmark one inch of solid wood has an r value of 1.
When determining how much insulation you need don t guesstimate calculate.
Atticat expanding blown in pink fiberglas insulation nominal bag weight 28 5 lbs.
Let s start with an example.
Click the button to calculate the depth in inches and pounds of total insulation required for this job.
Input depth of existing blown in insulation in inches.
Minimum thickness inches minimum settled thickness inches 13 5 9 168 5 0 169 4 75 4 75 19 9 1 109 5 0 26 7 7.
Blown fiberglass installed in the attic has an r value of 2 2 per inch so 12 inches of it would give you an r value of 26 4 in your attic installation project.
An r value is also calculated per inch of width.
The total r value of installed insulation is.
R value bags per 1000 sq.
The r value of loose fill cellulose is r 3 2 to 3 8 per inch2.
Loose fill fiberglass has an r value of r 2 2 to 2 7 per inch3.
Input length width and desired r value of the area to be insulated.
The higher the r value the greater the insulation performance.
In comparison an inch of blown fiberglass insulation has an r value of 3 1 3 4 and an inch of blown cellulose in an attic has an r value of 3 2 3 7.
R stands for resistance and the higher an insulation s r value the more efficiently it resists transfer of heat from a warm zone into a cooler zone.
How is insulation r value calculated.
R value measures how well certain building insulation materials can resist heat.
Achieving the desired r value depends on both the depth of the insulation and its density.
Know exactly how much you need with our project calculators.
As you can see there s some variation in r value depending on the particular type and brand of products used.
R value is a measurement of thermal resistance and measures the ability of heat to transfer from one side of an object to another.