To make your home truly energy efficient, you should make sure it is well insulated to make it more comfortable and reduce your heating and cooling costs. Properly installed insulation reduces heat loss and gain through your home’s building envelope. There are a few different types of insulation; the best type and form for your home depends on your climate, whether you are adding insulation to a new or existing home and whether you are hiring a professional or completing the installation yourself.
There are four general categories of insulation:
- Fiberglass batt
- Rigid foam board
- Spray foam
Common types of loose-fill and blown insulation include fiberglass/mineral wool and cellulose. Fiberglass/mineral wool insulation manufacturers spin this insulation in a similar fashion to how booths at carnivals spin cotton candy, but use melting glass or rock instead of sugar. Cellulose is made of ground-up newspaper that has been treated with fire retardant.
Loose-fill or blown insulation is commonly used in existing homes as well as in new construction. Both types can be installed at a high density (dense-packed) or blown in to a wall cavity. This type of insulation is generally used on attic flats and slopes of low to moderate pitch (less than six inches).
Fiberglass batt insulation
The loose fiberglass or mineral wool fibers used in loose fill can also be held together with a type of adhesive to create batts or blankets that can then be used to insulate your walls. Fiberglass batts can be used anywhere in your home as long as they are properly supported: attic flats, attic slopes of any pitch, open walls or knee walls in existing or new construction and more.
Rigid foam board insulation
Rigid foam board insulation serves a variety of purposes, including structural strength, thermal break, exterior sheathing and serving as an air barrier in addition to insulating your home. Types of rigid foam board insulation include EPS (expanded polystyrene), XPS (extruded polystyrene) and polyisocyanurate.
Rigid foam board is commonly used in both retrofits and new construction as a continuous insulation (not to fill in wall cavities). In new construction, it can be used on the exterior or interior as a continuous layer before laying down siding or drywall. In retrofits, it can be used to contain any blown insulation or to support batt insulation.
Spray foam insulation
The most common type of spray foam insulation is spray polyurethane foam (SPF), which comes in high-density (closed-cell) and low-density (open-cell) forms. Both types require a thermal barrier to provide some protection during a fire. The most commonly used thermal barrier is ½-inch drywall.
Spray foam insulation is commonly used in both open or exposed cavities in both new construction and retrofits. In attics, it is typically applied to the underside of roof rafters. It is especially suited for insulating band joists, as it seals and insulates.
These are the four most common types of insulation used in homes in the United States. It is hard to say which type is best for your home, but it is important to note that it won’t matter which material you use if it is installed incorrectly. Whether you are hiring a professional or doing the work yourself, be sure that the insulation completely fills any cavities you are insulating. Any voids that are left behind can decrease the performance of your brand new insulation. Check out the Department of Energy website to read some frequently asked questions about insulation.