Types of Insulation and Guide to Installing

Insulation acts as a barrier between the climate inside your home and the climate outdoors. Proper insulation makes every room of your home comfortable and pays for itself over time in energy savings. To get started, you'll need to make sure that walls, roofs and those seldom-used nooks in your home are all properly insulated.

How Much Do You Need?
The first step to insulating a home is to determine how much insulation you'll need to get the job done. This is based on several things:

• Where you live (different climates call for different insulation needs)
• The type of house that you have (the type of foundation, how many levels it is, its age, the number of windows)
• How you heat and cool your house (heat pump, furnace, central air, window air conditioners)
• Local building codes

When considered together, these elements determine your R-value, or the amount of insulation your home requires. The bigger the number, the bigger your insulation needs. As a general rule, homes in colder northern climates have a higher R-value than those in the South.

Check with your local home center and building inspector to find out what the recommended R-value is in your area. Building codes will specify a minimum R-value. This corresponds to the R-value of the insulation you will buy. You can go higher than the minimum without worry, but you'll need to compare the extra insulation costs against potential energy savings, which could be minimal.

Types of Insulation Materials
When selecting insulation, there are four main types to choose from. These include:

Fiberglass: This is the most widely used form of insulation. It is made of spun glass, and can be purchased in precut batts, rolls or blankets. It's easy to install, but the dust it creates will make you itch like crazy. Wear long sleeves and pants, gloves and goggles to keep the irritation to a minimum.

Cellulose: Cellulose insulation is made from recycled paper that is treated to be bug and fire-resistant. It can be installed by hand or blown on wet with a machine.

Rock Wool: Rock wool insulation is made of actual rock that has been spun into soft fibers. It can be purchased in batts, blankets or as loose fill that is blown into walls.

Foam: Foam insulation is typically polyurethane-based. It can be purchased as a spray that expands to fill in areas or as foam boards that can be installed anywhere insulation is needed. In most cases, foam insulation needs to be installed by professionals. It is the most expensive option, but also the most energy efficient.

Where to Insulate
A well-insulated home is insulated from attic to foundation, but your budget may not make it possible to tackle your home's entire insulation needs at once. If you're insulating in stages, work through your home in the following order:

1. Attic: The attic is the area most vulnerable to heat transfer. According to the US Department of Energy, attics should usually have R-22 to R-49 insulation. Make sure that the area beneath your roof is insulated first. Then concentrate on the attic floor to keep heat and air conditioning in the rooms that you use.
2. Ceilings: Cathedral ceilings are also extremely susceptible to heat loss. Foam board insulation is the material most commonly used for this type of installation.
3. Walls: Newer homes should have insulation in all exterior walls. Older homes may not, or they may have insulation that doesn't meet current requirements. It's best to call a professional for guidance; the most practical solution is usually blown-in foam insulation.
4. Crawlspaces: An uninsulated crawlspace can cause cold air to seep into your house during the winter months. If this appears to be a problem in your home, consider adding insulation to the space, either under the subfloor for ventilated crawlspaces or along the subwalls for unventilated crawlspaces.
5. Basements: In most cases, there's not a lot of value in insulating a below-grade basement because the ground acts as insulation. If cold air is seeping through the floor, however, you'll benefit from insulating the basement ceiling.

Shopping for Insulation
Manufacturers are required to list the R-value of insulation on the packaging. This makes it easy to match a given type of insulation to your needs.

Some insulation has a vapor barrier on one side. In variable climates, this helps to prevent condensation from forming. For exterior walls and ceilings, choose insulation with the vapor barrier. For interior walls and floors, it usually isn't necessary.

Check the space that you have available before you buy insulation. To get a higher R-value, some types of insulation must be thicker. Compressing it to make it fit into a space reduces the R-value.

Installing Insulation
Check the manufacturer's instructions to see how insulation should be installed. For batts and rolls, you'll need full access to the space to roll the insulation out correctly. This could mean removing floorboards or interior walls. For foam and fills, you'll need to drill holes in walls or floors to pump the material into place.

Insulation Tips

1. Make sure that the area you're insulating is properly ventilated. Keep soffit and other ventilation systems clear. Sealing out the air completely encourages mold growth.
2. A vapor barrier must face the living space. This will prevent moisture from building up in the insulation.
3. Be especially careful when installing insulation near light fixtures. Only fixtures labeled as IC, for direct insulation contact, should be placed up against insulation.