Roof System R Values

The average r value for some common roof materials include.

Roof system r values.

It uses the iso thermal planes method the same method as used in nzs4214 2006. For example two inches of extruded polystyrene with an r value of 11 has an rsi of 1 93721. 0 00 per inch of thickness tpo. Rsi r value système international is the metric equivalent.

The way it works is simple. 6 6 per inch xps insulation. To convert rsi to r value multiply the rsi by 5 67826. Some of the possible material combinations may not be suitable for actual constructions i e.

R value table for roofing materials and building insulation. 0 34 per inch of thickness bur smooth. 5 0 per inch eps insulation. To convert the r value of a specific thickness of a material to rsi divide the r value by 5 67826.

6 6 per inch of thickness metal. R value because many states or regions require that a roof system have a minimum amount of thermal resistance on commercial industrial and or institutional buildings. Here are the r values of the most popular commercial roofing systems. Eps based claddings directly fixed on timber framing.

This webpage calculates the r value of walls roofs and suspended floors for most insulation material r values. The higher the r value the better a material performs as a thermal insulator. 3 85 per inch polyiso. 0 33 per inch of thickness bur gravel.

The higher the r value the more the material insulates. 0 24 per inch of thickness epdm.