Roof R Value Calculator

The r value calculator is best used as follows.

Roof r value calculator.

For each different material multiply the thickness by the standard r value per inch for that material. Eps based claddings directly fixed on timber framing. Input depth of existing blown in insulation in inches. Click the button to calculate the approximate r value for this job.

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. This calculator is to be used as an estimating tool only. This webpage calculates the r value of walls roofs and suspended floors for most insulation material r values. It uses the iso thermal planes method the same method as used in nzs4214 2006.

Our calculator helps you measure what r value for exterior walls you may be looking for as well as for different applications. 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. Add the results for all the materials together to get the total r value for the roof assembly. Class 2 high rise apartment a building containing 2 or more sole occupancy units each being a separate dwelling.

Includes multi unit residential buildings. Some of the possible material combinations may not be suitable for actual constructions i e.