Several weeks ago, my mom called me almost in a panic. This is nothing new -- it seems that most calls from mom in the middle of the day have a certain importance about them. This time she was concerned with the insulation -- or lack thereof -- located in the attic area of her home. She wondered if there was sufficient insulation to keep her warm this winter.

Therefore, like a good son, I planned a trip to her home to assess the situation and offer my opinion. Why do I share this situation with you? Well, perhaps you may be in a similar panic. So, let's talk insulation.

Insulation comes in many shapes and sizes. There are also many different techniques of installation used based on the era in which the home was constructed, the applicable thermal codes at the time, and the upgrades in regard to remodeling projects.

The most common type of attic insulation used currently is called cellulose. This type of insulation has been widely used in construction for about the last 15 to 20 years. Cellulose insulation has the appearance of deformed or shredded cotton balls and is installed by being "blown-in" through a 4-inch tube that is connected to a truck. Current thermal code requires an R38 insulation factor in the attic area. This is about 14 inches of insulation. This product is very cost-effective. An attic with about 1,500 square feet of coverage could be insulated for about $300 to $400.

From the late-1960s and early-1970s to about 1990, fiberglass insulation was the common type used in attics. This was typically pink or yellow in color and would make one itch rather easily upon coming in contact with the skin. The typical R factor for this time period was 19 to 24. If this describes your situation, the best advice I could give would be to add an additional R19 factor of cellulose insulation directly on top of the existing fiberglass base.

Prior to the mid- to late-1960s, there were many types of insulation used because there was not a strict enforcement of applicable thermal code. A common type of insulation used at this time was called "rock," because it has the appearance of small pebble-sized rocks. In many instances, this type of insulation contained asbestos. The common R factor of this type of insulation was about an R13. I am frequently asked about the dangers of asbestos insulation and there are many scenarios. To be brief, I suggest that unless you plan on an extensive remodeling and replacing the attic insulation, simply add an additional R24 factor of cellulose insulation over the top of the existing layer.

A basic lesson of code for exterior walls in a basement or above-ground floor is R13. An R19 factor would be needed between floor joists between the basement and main floor level.

If you would like to submit a home remodeling or home improvement question to be addressed in this column, please e-mail them to Joel Jones at joelthehomeinspector@msn.com.

Joel is the owner of "The Inspector," a home and building inspection company and a home improvement and remodeling consultant.