R Values For Roofs

The way it works is simple.

R values for roofs.

Know exactly how much you need with our project calculators. Always check with your local code authority. Therefore its r value is reduced by 17 to r 2 1. 0 24 per inch of thickness epdm.

Insulation with r 2 5 is compressed from 94mm to 78mm i e. Please note that the r values for roof membranes shingles tiles air films and roof deck materials might or might not be permitted by your local code to be included when total roof assembly r value is being calculated for the purpose of satisfying energy code requirements. Location of r value on a product data sheet. 0 24 per inch of thickness.

The higher the r value the greater the insulation performance. Types of roof insulation. The higher the r value the better a material performs as a thermal insulator. A material s r value is the measure of its resistance to heat flow.

0 33 per inch of thickness bur gravel. If insulation is compressed its r value is reduced by its compression. 0 34 per inch of thickness bur smooth. R value table for roofing materials and building insulation.

It is important to know the 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. 6 6 per inch of thickness metal. Here are the r values of the most popular commercial roofing systems. For example two inches of extruded polystyrene with an r value of 11 has an rsi of 1 93721.

To convert rsi to r value multiply the rsi by 5 67826. R value is used as a measurement of the effectiveness of thermal insulating materials. The higher the r value the more the material insulates.