REMODELING ARTICLE - WHAT IS INSULATION?

Insulation is defined as a material or combination of materials which retard the flow of heat and/or sound.

There are five basic reasons to insulate: thermal comfort, acoustical comfort, moisture and fire protection and environmental conservation.

Thermal Comfort: Insulation resists the flow of heat. Heat is a form of energy, it always travels from hot to cold flowing outward in winter and inward in summer. By reducing heat flow, a properly insulated home uses less energy in winter for heating and less in the summer for cooling.

Heating and cooling account for 50 to 70 percent of the energy used in the average American home -- about 20 percent goes for heating water. On the other hand, lighting, appliances, and everything else account for only 10 to 30 percent of the energy used in most residences. Inadequate insulation and air leakage are leading causes of energy waste in most homes. Insulation saves money and our nation's limited energy resources. It can also make your house more comfortable by helping to maintain a uniform temperature throughout the house. Walls, ceilings, and floors will be warmer in the winter and cooler in the summer. Unless your home was recently constructed with special attention to energy efficiency, adding insulation will probably reduce your utility bills. Most existing homes in the United States are not insulated to the best level. Older homes are likely to use more energy than newer homes, however even a new home can often benefit from adding insulation. Furthermore, insulating your home will typically save enough money in reduced utility bills to pay for itself within a few years, continuing to save you money for as long as you own the home and increasing it's resale value. Many lending companies will even finance your project. Often the monthly savings on your utility bills will be equal to your monthly loan payments. And the savings never stop, as utility costs rise the insulation in your home saves you even more money.

Acoustical Comfort: Insulation is also an excellent sound absorber as well as an energy saver. When installed in the walls and ceilings, it can reduce the transmission of sound. Sound transmission is noise that travels from room to room, from home to home, or from appliances such as washers, dryers, heating and air conditioning systems, phones, radios and TV's. Special and standard insulation materials can be used to encase or enclose a noise generating source, forming a sound barrier between the source and the surrounding area. Insulation placed in walls and ceilings can provide a barrier to the entry of sound from the outside or other rooms.

Moisture: All types of insulation perform differently with exposure to moisture. Insulation will lose its insulating efficiency or R-value when wet. Exposure to water can also promote mold growth, dry rot, and the potential for health problems. It is important when choosing what type of insulation is right for your home, to determine what effects moisture has on it and what applications it is best suited for.

Fire protection: Used in combination with other materials, insulation helps provide fire protection in framing systems throughout your home. It is important to keep this in mind when retrofitting or adding additional insulation to your home. I would not suggest installation of materials that do not have the best fire ratings around areas of your home that have a higher potential for fire. For example a gas furnace, kitchen or if your home is not up to current UBC electrical wiring standards.

Environmental: Just keep this in mind, the electricity generated by fossil fuels for a single home puts more carbon dioxide into the air than the average car. Better insulation means lower energy use. You get the picture.

Insulation is rated in terms of thermal resistance, called R-value, which indicates the resistance to heat flow. The higher the R-value, the greater the insulating effectiveness. Always be sure to install the correct R-Value recommended for your area. Manufacturers of insulation products print the R-values of their products either on bags or on labels attached to plain bags. In most cases, R-values are also printed on the facings of bats and rolls. On unfaced insulation, the R-value is printed on the product or indicated by stripe coding.

The amount of energy you conserve will depend on several factors; your local climate, the size, shape, and construction of your house, the living habits of your family, the type and efficiency of the heating and cooling systems and the fuel you use. Once the energy savings have paid for the installation cost, energy conserved is money saved and the annual savings will increase if utility rates go up.

When insulating a home, it is important to get the R-value specified by the builder or the local building code. It's also important that the product provide long-lasting thermal performance. While R-value "per inch" is promoted by some manufacturers, the overall R-value installed is what counts. More R-value alternatives provide greater flexibility in meeting code energy requirements in your area. Keep in mind that the area of your home you are insulating determines what R-rating will be needed for installation. For instance, a ceiling requires a higher R-value than a basement concrete wall. A great resource for determining what R-values to use in your home is located at: www.ornl.gov/roofs+walls/insulation/ins_05.html. For more information on insulation recommendations for a specific area, contact the local building department or the local gas or electric utility for their recommendation.

There are three basic kinds of insulation most commonly found in today's construction.

Fiber glass insulation is made from molten sand or recycled glass and other inorganic materials under highly controlled conditions. Fiber glass is non-combustible, however most facings attached to fiber glass insulation are combustible and should never be left exposed. Other special flame-resistant facings may be left exposed where desired, such as on a basement or crawl space wall. Fiber glass insulation is not absorbent and, if exposed to moisture, will not wick up or hold water and will not support the growth of mildew, mold or bacteria. It will dry out and retain its original R-value. it is most commonly package in rolls or squares (bats) that are sized to fit between wall, ceiling and floor studs. Fiber glass insulation can also be blown into an attic space to nearly any R-value.

Cellulose insulation is mostly commonly found in ceilings and attic spaces. It is made primarily of ground-up or shredded newspaper, which is naturally combustible. To protect against fire, cellulose insulation is heavily treated with fire retardant chemicals. Though it is treated with fire retardants, it is not fire proof. This means the insulation could still burn if exposed to a heat source. However this insulation is inexpensive, non toxic and easy to install. Cellulose materials are spread out in an even layer when installed and can be added to relatively easily by simply spreading more over the existing material. Cellulose insulation can also be blown into an attic space to nearly any R-value.

Foam board insulation comes in sheets and is used for all areas of construction from basement to roof from walls to floors. This is commonly used in new construction because of its ease of installation and its R-values. This is not, however, an easy installation for existing homes unless you are planning on doing an addition or extensive remodel. I would not recommend this type of product for retrofitting a home. Check out www.dow.com/styrofoam/index.htm for a look at this product if you are interested.

A fourth type of insulation is becoming more popular, spray foam insulation. This type of insulation can be used in either new construction or existing buildings. It is installed through a spraying process either directly or by injecting it into an area. My neighbor had this insulation installed in his home. The process was simple. The installer drilled small access holes into the walls of the house, sprayed the foam into these holes and patched them up. I have been informed however that there is a down side to this insulation alternative. When installing into an existing structure the foam can create too good of a barrier within the walls, not allowing them to breath and trapping moisture inside. This can lead to rot inside the walls. I would investigate this alternative before deciding this is the solution for your home. In addition this is not a solution that you can apply yourself, it requires a licensed specialty contractor with the proper equipment to perform the work. For a good example of this type of insulation visit www.airkrete.com.

The material you choose will depend on local codes and the type of application. It is possible to add insulation to almost any house. You may be able to do the job yourself if the structural framing is accessible, for instance in unfinished attics or under the floor over an unheated space. Or, you may prefer to hire an insulation contractor. In either case, it is important to choose and install the insulation correctly. It is most important to insulate your attic to the recommended level, including the attic door, or hatch cover. Provide the recommended level of insulation under floors above unheated spaces, around walls in a heated basement or unventilated crawl space, and on the edges of slabs-on-grade. Use the recommended levels of insulation for exterior walls for new house construction. When remodeling or re-siding your house, consider using the levels recommended for new construction in your existing walls. Also, insulation of water pipes will increase efficiency of appliances, provide protection against freezing and deliver hot water throughout your home faster.

Sources
NIA (National Insulation Association); www.insulation.org
DOW; www.dow.com
NAIMA North American Insulation Manufactures Association; www.naima.org
USA INSULATION; www.usainsulation.com
DEPT. OF ENERGY INSULATION FACT SHEET; www.ornl.gov/roofs+walls/insulation/
AIR KRETE; www.airkrete.com