R Values For Roofs

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.

R values for roofs.

R value measures how well certain building insulation materials can resist heat. 0 00 per inch of thickness tpo. For example two inches of extruded polystyrene with an r value of 11 has an rsi of 1 93721. 0 24 per inch of thickness epdm.

To convert rsi to r value multiply the rsi by 5 67826. A material s r value is the measure of its resistance to heat flow. 0 24 per inch of thickness. 0 33 per inch of thickness bur gravel.

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. Here are the r values of the most popular commercial roofing systems. Insulation with r 2 5 is compressed from 94mm to 78mm i e. Types of roof insulation.

The way it works is simple. Always check with your local code authority. R value table for roofing materials and building insulation. R value is used as a measurement of the effectiveness of thermal insulating materials.

The higher the r value the greater the insulation performance. If insulation is compressed its r value is reduced by its compression. The higher the r value the more the material insulates. 6 6 per inch of thickness metal.

0 34 per inch of thickness bur smooth. Therefore its r value is reduced by 17 to r 2 1. When determining how much insulation you need don t guesstimate calculate.