Roof Insulation R Value Calculator

Typical recommendations for exterior walls are r 13 to r 23 while r 30 r 38 and r 49 are common for ceilings and attic spaces.

Roof insulation r value calculator.

To calculate the total r value of a roof assembly. Our calculator helps you measure what r value for exterior walls you may be looking for as well as for different applications. R value of insulation is the most important guiding factor on the ability of the insulation to reduce heat flow up or down. To convert the r value of a specific thickness of a material to rsi divide the r value by 5 67826.

This calculator is to be used as an estimating tool only. For example two inches of extruded polystyrene with an r value of 11 has an rsi of 1 93721. Work out all the different materials and surfaces that make up the wall ceiling or surface you want to work out the r values and u values for. R value is a measurement that rates how resistant a product is to heat flow measuring the ability of heat to transfer from one side of an object to another.

Building insulation of course is what we are normally referring to when we say thermal insulating materials but in a commercial roof system the r values of other components such as cover boards and certain adhesives can often be included when calculating the total r value of the system. The r value calculator is best used as follows. Remember the horizontal or vertical orientation of the material is important to get its insulation value correct. Our insulation pack calculator will help you work out the area to be insulated and provide a recommendation on the number of packs required for your project.

Input depth of existing blown in insulation in inches. Click the button to calculate the approximate r value for this job. As a result the higher the r value the better the insulation properties when it comes to roof insulation in fact what this means is by increasing or decreasing the thickness of the insulation one can change the effectiveness. For example if you have a type of insulation that has an r value of r 5 per inch of thickness you will need a depth of 6 inches of this insulation installed in your attic to reach r 30 if you live in zones 2 or 3.

To convert rsi to r value multiply the rsi by 5 67826. Ceiling insulation r value r value for walls and more.