Rigid Insulation R Values Thickness

Understanding r value thursday december 13 2018 what does r value mean.

Rigid insulation r values thickness.

Because of this i often get questions about which type of foam board insulation to use and what r values these products provide. Our r value guide to rigid insulation includes the doe s recommended insulation by zone chart r value calculator and base building material r values chart. There are three basic foam insulation board products on the. Along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system.

I ve written several posts about how to insulation basement walls in which i promote the use of foam board insulation as the first line of defense against moisture and mold. For example a wall with 3 fiberglass batting r value of 10 8. Rigid insulation r value by comparison usually ranges from r 4 0 to 6 5 and may get as high as r 8 7 depending on the insulation material. Rigid insulation is usually made up of fibrous materials or plastic foams.

In comparison an inch of blown fiberglass insulation has an r value of 3 1 3 4 and an inch of blown cellulose in an attic has an r value of 3 2 3 7. The r value for foamular xps insulation is provided from testing at two mean temperatures 40ºf and 75ºf and from two aging conditioning techniques 180 day realtime aged as mandated by. Foam board insulation types. Traditional loose fill insulation such as fiberglass or cellulose has an r value between r 2 0 and 3 5 per inch of thickness.

Because rigid foam plastic insulation products are not all aged in accordance with the same standards it is useful to publish comparison r value data.