Choosing the Best Basement Insulation Materials

Basement insulation is a great way to conserve energy and increase the livable area of your home. Care must be taken, however, in selecting the method of basement insulation because the basement presents unique challenges.

Basement Insulation Choices
Basement walls are subject to moisture from a number of fronts. Moisture can condense against the interior wall, it can be drawn into the concrete from footers or it can leak through cracks and pores in the concrete. It's not really a question of "if" your basement will attract moisture; it's more of a question of "when" it will attract moisture.

Moisture can reduce the effectiveness of insulation and can promote the formation of mold and mildew. Choosing a basement insulation material should involve keeping the realities of moisture in mind. Your choices include:

• Blanket - Long a popular insulation material, fiberglass batts and rolls are still routinely used for basement insulation. Research by the Department of Energy, however, has shown that fiberglass blanket insulation is a poor choice given that moisture degrades its insulating ability quickly and that this type of insulation succumbs easily to mold and mildew.
• Concrete block - There are several techniques for insulating concrete block used in foundation construction. These involve pouring expanding foam or foam beads into the cavities of the blocks during construction. This is a very effective insulating strategy for new home construction.
• Foam board - Rigid foam insulating boards don't have the same moisture issues as blanket insulation. Foam boards can be expensive, however, and need to have a fire-resistant barrier (typically drywall) installed under most building codes.
• Exterior - Insulating the exterior of the foundation is another new construction strategy for insulating a basement. Exterior insulation can be costly, however, and protecting the above grade portion can be problematic.
• Loose fill - When basement walls are finished, loose fill insulation like cellulose or rock wool. While cellulose is typically treated to be mildew and fire resistant, rock wool might be a better choice for basement insulation.
• Sprayed foam - Applied as an expanding liquid, sprayed foam insulation can be a good choice for existing basement. Most building codes require sprayed foam to be covered with an approved thermal barrier-typically drywall-which means sprayed foam is best used in situations where a finished basement is the ultimate goal.