Most homes have several different types of insulation. For example,
attic floors are often insulated with fiberglass batts or cellulose,
while many basement walls are insulated with rigid-foam panels. For a
variety of reasons, you probably don’t want to insulate your basement
walls with cellulose or your attic floor with rigid-foam panels.
you’re selecting insulation, you need to make sure that your chosen
material is appropriate for its intended location, that it will perform
well, that it won’t be prohibitively difficult to install, and that it
won’t blow your budget.
The higher a material’s R-value, the
better it is at resisting heat flow. In most cases, insulation with a
high R-value per inch is preferable to insulation with a low R-value per
inch, and insulation that resists airflow is preferable to
air-permeable insulation. To save money, however, many builders choose
air-permeable products with a low R-value. As long as air leakage is
addressed by installing a tight air barrier and as long as an adequate
thickness of insulation is installed, even inexpensive insulation
products can perform well.