How to Find the Right Type of Insulation
What is R-Value? The R-Value of insulation is a measurement of how resistant a section of insulation is to heat flow. Technically, it stands for Thermal Resistance. That term is fairly self explanatory, but can be easily wrapped up by saying that R-Value is a measurement of how much heat is allowed to pass through a section of insulation. The higher the value, the more resistant it is to heat flow. Thus, the higher the value, the more your heat stays inside the house in the winter, and the more the heat stays outside in the summer.
The R-Value that you need is usually determined by local building codes according to where you live. Florida and Maine are going to have very different insulating needs within a residential building. Your local code enforcement office should be able to provide you with a detailed list of recommendations for your area. Everything from the floor, to walls, to the attic should be included, and all are usually insulated with different values to maximize the energy efficiency of the house.
Having developed a little working knowledge of what insulation does, let's take a look at several different types and some common applications for each.
Fiberglass insulation usually comes in long rolls. Sometimes these rolls are pre-cut into specific lengths known as batts. The fiberglass insulation functions like a giant blanket that can be placed between the studs in your wall, rolled out between the rafters in your ceiling, or stapled between the joists in your floor.
The thickness of the roll of insulation is what determines the R-Value. A common mistake is to buy a high R-Value insulation and then try to smash it down to make it fit into a tight spot. Smashing the insulation actually decreases the R-Value. The insulation works by trapping air in between the spun particles of fiberglass, and this process is not allowed to happen when the insulation is smashed flat. Follow the guidelines that are given by the manufacturer to allow the insulation to function as it was intended. You will save money in the long run when the product is allowed to function properly.
Foam insulation comes in sheets of varying thicknesses. Usually they are 4" x 8" and can easily be cut with a utility knife to whatever size you need. As with fiberglass, the thickness determines the R-Value. Foam insulation boards are generally not as efficient as fiberglass batts. The insulation value just isn't as high. There are, however, a few instances where foam insulation is ideal to use. It can be used on concrete basement walls to enhance the insulating value of the concrete and also function as a moisture barrier. It can also be used as an extra layer of protection on the outside of the house, and you will often see it installed underneath vinyl siding.
Blown-in insulation is exactly what its name implies. It is made up of different types of shredded material that are blown through a large vacuum system into your attic or walls. This creates a nice big fluffy blanket that works very well to eliminate heat transfer through your roof. The R-Value is determined by taking a ruler and measuring how thick the insulation is after it settles. This type of insulation works very well, but you can't disturb it. If you are in your attic moving stuff around all the time and walking through the blown-in, you will destroy the R-Value. If you are active in your attic a lot, then fiberglass rolls is probably the best way for you to go.
By doing a fairly quick analysis, you can determine your needs and then project your needs to the products that are available. This will allow you to make the best decision as you choose the right insulating solution for your home. The most important thing is that, if you feel like your home is not insulated properly, you do something about it. Most people underestimate just how much of a difference a properly insulated home can make on their utility bills. It can also have a direct effect on energy concerns. During peak usage seasons, you can make a big difference in the amount of energy that is consumed by maximizing the efficiency of your own living space. As population densities continue to increase, the ability to conserve as much energy as possible becomes more important every year.
Brian Simkins is a freelance writer living in Chicago. He enjoys using his 14 years of home improvement experience to educate and equip new home owners.