This webpage calculates the r value of walls roofs and suspended floors for most insulation material r values.
Roof r value calculator.
Eps based claddings directly fixed on timber framing.
The r value calculator is best used as follows.
It uses the iso thermal planes method the same method as used in nzs4214 2006.
Click the button to calculate the approximate r value for this job.
Input depth of existing blown in insulation in inches.
Remember the horizontal or vertical orientation of the material is important to get its insulation value correct.
Includes multi unit residential buildings.
Add the results for all the materials together to get the total r value for the roof assembly.
This calculator is to be used as an estimating tool only.
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.
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.
Some of the possible material combinations may not be suitable for actual constructions i e.
To calculate the total r value of a roof assembly find the total thickness in inches of each type of insulating material within the system.
For each different material multiply the thickness by the standard r value per inch for that material.