R Values For Roofs

For example two inches of extruded polystyrene with an r value of 11 has an rsi of 1 93721.

R values for roofs.

R value is used as a measurement of the effectiveness of thermal insulating materials. Location of r value on a product data sheet. R value table for roofing materials and building insulation. The higher the r value the better a material performs as a thermal insulator.

0 00 per inch of thickness tpo. The higher the r value the greater the insulation performance. A material s r value is the measure of its resistance to heat flow. 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.

0 34 per inch of thickness bur smooth. Know exactly how much you need with our project calculators. The higher the r value the more the material insulates. Therefore its r value is reduced by 17 to r 2 1.

Here are the r values of the most popular commercial roofing systems. 0 24 per inch of thickness epdm. Always check with your local code authority. The way it works is simple.

Insulation with r 2 5 is compressed from 94mm to 78mm i e. R value measures how well certain building insulation materials can resist heat. 6 6 per inch of thickness metal. 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.

To convert rsi to r value multiply the rsi by 5 67826. If insulation is compressed its r value is reduced by its compression. When determining how much insulation you need don t guesstimate calculate.