Which type of insulation is "good'?

Now that I know what how insulation works, I need to know how to distinguish between "good" insulation and "bad" insulation. One of the most simple ways of distinguishing whether an insulation material is "good" or not is by looking at the R-values. All insulation is rated in thermal resistance, called R-value. The R-value indicates the resistance to heat flow, so the higher the R-value, the better.

Another important piece of information that I found out was that not all types of insulation is safe to install by yourself. Some materials might need a professional to install, so when I am choosing the materials, I must remember to read the label carefully.