Insulation Comparison Guide
Blankets and batts
Blanket and batt insulation is sold in bundles (batts) or rolls (blankets). They are relatively inexpensive. Proper installation is essential for the best performance: sealed cavity or bay with an air barrier on all six sides. Small voids due to sloppy installation and/or sagging can significantly impair performance.
Rigid foam board
This insulation is easy to use and an easy DIY way to add insulation to existing assemblies. It can be used almost anywhere and comes in a variety of thicknesses and facings. However, foam manufacturing uses CFCs and other toxins. Likewise, off-gassing and deteriorating R-values in some circumstances are worth considering.
Rigid fiber board
An alternative to rigid foam, rigid mineral wool board, largely comprised of rocks, can have high recycled content and contains no blowing agents or CFCs. It is durable and versatile; it is also fire resistant, non-combustible, sound-absorbent, and water repellant. Read the Fact Sheet.
Loose-fill and blown in
One of the most practical solutions for insulating old houses, loose insulation can be blown into existing attic and wall assemblies without removing interior wallboard or exterior sheathing and siding.
It can settle well into cracks; however, it also settles so that the tops of stud bays originally filled may become voids in time, and other obstructions can block areas from being filled.
Spray foam can help make a house airtight; it works as a vapor barrier and it adds significant insulation. There are two types of foam-in-place insulation: closed-cell and open-cell. Budget and use will determine which is a better choice. Today, most foaming agents don't use CFCs or HCFCs, however, air quality and end-of-life disposal of the product and anything it touches are still important considerations.
Structural insulated panels (SIPs)
SIPs include an insulated core sandwiched between two structural facings. Because the insulation is built-in within factory conditions, the airtight tolerances are tight and the system generally performs better than site-installed systems. Types include: Foam board core, Liquid foam core, Straw core insulation
Reflective insulation reflects escaping heat back in the direction of your home’s interior. Foil insulation works best when it is placed near the heat source. During the summer months, it reflects the heat away from your home to lower your AC usage. Types include foil-faced materials such as kraft paper, plastic film, polyethylene bubbles, and cardboard.