Roof Insulation Dimensions

Board size 4 x 4 1 21 m x 1 21 m.

Roof insulation dimensions.

The higher the r value the better a material performs as a thermal insulator. Location of r value on a product data sheet. 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. When correctly installed tapered insulation helps eliminate problems due to ponding water and can extend the longevity of your low slope roofing system.

So you need to know an insulation product s thickness as well as its r value in order to compare it to another product. The same insulation will hold more heat the thicker it is installed. Since modern two by fours are not 4 inches the true depth of the wall cavity is 3 1 2 inches. Types of roof insulation.

Eight inches of poor quality insulation may have a higher and better r value than one inch of top quality insulation. Insulation for 2x4 walls most wall assemblies especially those in older homes are built with two by four 2x4 studs. R value table for roofing materials and building insulation. The standard tapered panel size is 4 x 4.

In most wall applications you will use r 13 or r 15 kraft faced fiberglass insulation rolls for these two by four stud walls.