Roof Insulation Dimensions

Location of r value on a product data sheet.

Roof insulation dimensions.

The higher the r value the better a material performs as a thermal insulator. R value table for roofing materials and building insulation. Since modern two by fours are not 4 inches the true depth of the wall cavity is 3 1 2 inches. 4 x 8 1 21 m x 2 44 m service temperature limits 100 to 200 f 73 3 to 93 3 c.

The same insulation will hold more heat the thicker it is installed. So you need to know an insulation product s thickness as well as its r value in order to compare it to another product. In most wall applications you will use r 13 or r 15 kraft faced fiberglass insulation rolls for these two by four stud walls. When correctly installed tapered insulation helps eliminate problems due to ponding water and can extend the longevity of your low slope roofing system.

Eight inches of poor quality insulation may have a higher and better r value than one inch of top quality insulation. R value is used as a measurement of the effectiveness of thermal insulating materials. Insulation tapered polyiso foam roof insulation 3 5 tapered polyiso insulation provides a logical and economical answer for roofs that do not permit adequate positive drainage like low slope roofs. Standard material is johns manville enrgy 3tapered and flat polyisocyanurate roof insulation.

Types of roof insulation.