Heat flows from warm areas to cool areas. It does this in three ways:

• Conduction - where heat is transferred directly from mass to mass
• Convection - transfer of heated air from one space to another (hot air rises, heavier cool air sinks)
• Radiation - simply means that any warm body/object gives off heat toward a cooler one.

The job of attic insulation is to reduce the transfer of heat with a minimum of solid conduction so that your home stays warmer in cool weather and cooler in warm weather. In this article deals with the qualities and applications of various types of known insulations and informs you on how best to evaluate R-values.

The R stands for resistance to heat flow. The greater the R-value, the greater the insulating power. R-value requirements depend on factors such as local climate and the surface you are insulating (ceiling, walls, floors, etc.) and are regulated by your local building codes. Contact your county or city building inspector for the specific insulation requirements for your area. Each region of the country has individual requirements for adequate amounts of insulation.

In most areas of the country, the local utility company will offer brochures with helpful suggestions on how to reduce your energy bills. Some will arrange to have an expert come to your home to point out areas that need to be insulated or weatherized. Often there is no charge for this service and it may even lead to low or no interest loan programs you may be eligible for. Also, state or federal tax credits may apply for any additional insulation work you may do.

Check with your State Energy Commission, local power company, or local home center for the optimum R-value in your particular region.

Safe-use practices are very important when you work with any type of insulation.

• Dust mask and goggles are necessary for work with all types of insulation.
• Fully cover your body, if possible long sleeves, a hood, long pants, and gloves.
• Always use the correct tool(s) for the job.
• Be sure power tools are properly grounded. Watch power cord placement so that it does not interfere with the tool's operation.
• A hard hat should be worn, since roofing nails may be sticking through the sheathing.
• If you are not allergic to tetanus shots, be sure yours is current. There are usually exposed, rusty nails in an old attic.
• Keep the insulation clear (3" or so) from objects that transfer heat to reduce fire hazards, and install sheet metal baffles around recessed light fixtures, chimneys, and flues.
• In older homes with possible frayed wires, do not allow the aluminum vapor barrier of batt insulation to come in contact with the wire, since it could short circuit and start a fire.
• Working in attics or other hot areas can cause loss of body salt by excessive sweating. A good idea is to take salt tablets. (Check with your doctor first)
• When working outside on a roof, wear shoes or boots with rubber soles; stay clear of power lines; secure extension ladders with safety hooks that clamp over the ridge; and delay your work until the roof is free from dampness of rain, frost snow, or dew.
• When working high on the outside of the house, you should use scaffolding to provide a balanced, level working surface.
• Do not step through attic floor joists onto the ceiling of the room below. It will give way.
• Some types of insulation are flammable. Check with your local building department and fire department for special application precautions or restrictions.

Caulk. A pliable material, usually forced into a gap or crack with a gun or pressurized can, hardens into an effective seal against air and moisture infiltration.

Cellulose. Blown-in or loose, consists of rock wool, glass fiber, vermiculite, and/or perlite. Use this in floors, walls, and hard-to-reach places. This type of insulation is poured between joists or blown in with special equipment. It is best suited for use in irregular-shaped areas and is the best option for blowing into existing finished walls.

Fiberglass. Blankets or batts, a popular insulator for walls, floors, ceilings, roofs, and attics. Fitted and stapled easily between studs, joists, and beams, I feel it is best suited for the do-it-yourselfer.

Flexi-vent. A waffle-like strip of plastic designed to allow air circulation to carry away moisture that could build up under insulation.

Foam. Extruded polystyrene, isocyanurate board, and fiberglass board. These rigid panels are used on unfinished walls, in new construction, or on basement and masonry walls or exterior surfaces. The panels are glued or cut to friction fit between studs, joists, or furring strips and must be covered with drywall or paneling for fire safety. They offer a high insulating value for a relatively thin material, but are highly flammable, and some chemically based sprays or foams may discharge poisonous films over a period of time. Be sure to use a closed-cell, waterproof rigid panel in exterior applications or in high moisture areas.

Furring. Strips of wood used to level out a surface prior to finishing.

Shims. Thin wedges of wood used to bring furring strips level with each other when used on an uneven wall.

Silicate compound. Made of glass and sand. It does not burn, release toxic fumes, nor attract vermin. It comes in lightweight easy-to-handle bags and should be used in the same manner as loose fill or cellulose.

Vapor barrier. Most common is a 6 mil. sheet of plastic attached over insulation to eliminate moisture infiltration and deterioration of insulation.

Open sun-facing curtains/blinds: Before you leave for work, open any curtains or blinds that face the sun to naturally reduce your heating bill.

Close the chimney flue: When you're not enjoying a fire in the fireplace, make sure that the chimney flue is closed, or you'll lose lots of heat through this gaping hole.

Close all windows completely: Just because your window looks closed doesn't mean it's tightly sealed shut. If there's a locking mechanism, lock it.

Turn down the thermostat: If you can, turn down the heat in rooms that you don't use regularly.

Older houses are a particular challenge, as there have been many updates in energy efficient construction and building design in the last decade alone. It's easy enough to check for drafts on a nice, cold day. From the inside of your house, feel for chilly air around problem places. Do something about cold winter drafts, you will save money and be more comfortable.

Places to look for drafts:

• Doors
• Light Switches
• Wall Sockets
• Windows