When attempting to insulate your home against escaping heat, R-38 insulation may provide just the degree of insulation you need. But this will depend on the climate you live in, and how cold or hot the temperatures may get in your area.
Advantages of R-38 Insulation
Regardless of the type of insulation you use, whether fiberglass, foam, or rigid, you can get the insulation ratings you need. It all depends on insulation quantities and thickness. R-38 rated insulation is considered the standard degree of insulation needed for homes in zones 1 to 5 in the U.S. It may be overkill for homes in milder climates. In climates with more severe temperatures it will usually be inadequate.