The Proper Installation of R-11 Draped Insulation in Basements
Draped insulation is a common term for blanket or batt and roll insulation, a type of insulation ideal for insulating certain parts of your home and is known for its lower cost compared to other insulation materials. Insulating your basement is a critical part of keeping your home comfortable and energy efficient, but blanket insulation in the basement should be thought of as a temporary expedient. If you aim to insulate your basement to an R-value of R-11, proper installation of the insulation is essential.
Use in Basements
Blanket or batt and roll insulation is generally less expensive than other types of insulation, recommending itself to homeowners on a tight budget. According to the Pennsylvania Housing Research Center, however, draped insulation offers only a temporary solution for insulating your basement, since draped insulation "puts the basement at risk for moisture issues" because the insulation's "vapor barrier does not allow the basement wall to dry toward the interior space."
Blanket insulation can be installed either vertically or horizontally. A typical installation places the blanket insulation against the top sill plate (the top horizontal wall joist to which the vertical wall joists attach) and secures the blankets to the sill plate using furring strips (thin strips of wood). Finally, patch tape is used to tightly seal the seams between the blankets. To ensure that the insulation delivers an R-value of R-11 when installation is complete, you will need to look for the R-value of the draped insulation you purchased and determine how many layers you will need to install to achieve a value of R-11.
It is always important to obtain installation instructions from the manufacturer whenever you can and to follow them exactly, particularly safety and proper handling instructions. Since the performance of your basement insulation depends in large part on the quality of the installation, proper installation is critically important. Even for a single type of insulation such as blanket insulation, installation methods can differ tremendously among different insulation manufacturers.
Because draped insulation, though less expensive than other types of insulation, is more prone to moisture problems, homeowners insulating their basements should consider using an alternative insulation material either in conjunction with or in lieu of draped insulation. According to the U.S. Department of Energy, loose-fill insulation, sprayed foam insulation and foam-board insulation are ideal for finished basements, while concrete block insulation and insulating concrete forms are a good choice for basements that have not yet been built.