Whether you're building a 20' x 40' shop in your backyard, or a 75' x 200' structure for your expanding business, you'll have some important decisions to make regarding R-value. R-value indicates the insulation's capacity to resist heat flow. The higher the R-value, the better the insulation's ability to hold heat, or keep your building cool. ...The post Which R-Value Should I Use? appeared first on CMI Insulation.