With the increasing energy prices the buzz on insulation, especially spray insulation, is getting louder. Homeowners are now learning that the key to increasing electricity and home heating costs is not to pay it. And the only legal way not to pay for it is to provide more insulation in the home so that the heating and cooling costs are drastically decreased.

Home insulation is not a new idea. For thousands of years civilizations have used straw, seaweed, sod and even snow to provide insulation for homes. The time-honored reason behind home comfort is to bond a weatherproof home outer shell with a substance that can hold heat or, in southern areas, cool air in the home. The outside covering blocks the wind, snow and rain allowing the insulation layer to maintain the comfort level.

Traditional Insulation Methods

Traditional forms of insulation are very good insulators. Fiberglass batts, rock wool and blown-in cellulose insulation have great R-values, which is a measurement of heat retention across a surface. All three have a factor of R-3.5 per inch, which means that a standard six-inch wall insulation in a wood frame house would attain R-21. This is a great insulation value and would make the home very energy-efficient. However there are long-term considerations:

1. Fiberglass Batts: This form of insulation comes in 15" by 47" batts that stay in the walls by friction it before being covered with a polyethylene vapor barrier. The problem is that, over time, outside humidity levels can cause the batts to slough a bit leaving a small space at the top. In addition, trough sloughing and imperfect fitting of the batts in the wall air can find its way in and form channels in the loose fiberglass. Air currents can find their way into the home through leaks. They also provide convection currents to draw heat outside.

2. Blown-In Cellulose Insulation: This type of insulation is actually made from recycled newspapers. Even though it is treated it is subject to compressing because of moisture and this can decrease the R-value. Rodents also like to tunnel through the cellulose and make nests in it. The holes can create convection currents that cause the R-value to deteriorate.

3. Rigid Foam Insulation: Have a thick slab of insulation is a great idea and this product is impervious to moisture. Two inches of rigid foam can give up to R-20. The only problem with this insulation is that it is very labor intensive top install. Also, all the edges have to be sealed against leaks.

Spray Insulation Weatherproofs

Spray foam insulation contains two separate liquid ingredients that are sprayed through a nozzle into the areas where needed: wall, ceiling, and under-floor areas. This mixed liquid expands into a solid cellular foam mat containing tiny, air-filled cells.

The benefits of spray insulation are numerous, especially for non-horizontal areas like cathedral ceilings and tall walls. When it is applied, it seals all the pores and small holes creating an air and water-proof shield. Once installed it will not sag, and some kinds even expand into areas that are hard to reach with traditional insulation.

Types of Spray Insulation

1. Closed Cell Spray Foam Insulation: This is also called "two-pound" or "medium density" foam and it expands from 20 to 30 times the size of its liquid form. It dries rigid with millions of microscopic air bubbles with an R-value of 7 per inch. Some closed cell sprays are made from soy beans meaning that there are no harmful odors.

2. Open Cell Spray Foam Insulation: This type of foaming application is also called "½ pound" or "low density" and can expand to over 120 times the size of its liquid form. Open Cell spray foam dries soft and, like closed cell, have pockets filled with air. The R-value of this dried foam is close to fiberglass or blown-in cellulose, or half that of the closed cell method. However, open cell spray foam is more effective than traditional insulation as it molds to fit the wall cavity.

For more information on spray foam insulation consult our Contractor Directory for an insulation contractor or post your project online.

Kim Kinrade writes for renovation, travel and news sites. When he is not doing this, or renovating old houses, he finds the time to write novels.