Every year new insulation products are introduced into the building industry. It used to be that crumbled up newspapers, old shoes and clothes were the best way to insulate walls in homes. Fiberglass, cellulose and now spray foam are the most common materials. What about these materials? Is one really better than the other? What should be the main factors homeowners consider when choosing to insulate their homes?



Spray foam, Cellulose and Fiberglass insulation are all good products.

There is a war of R-values. Manufacturers claim that their product has substantially greater R-value than their competitors. The fact is that there is not much difference.

R-value is simply a measurement of "resistance." It is a measurement of how resistant an insulating material to temperature differences. If the outside is freezing cold, then a higher resistance is preferred to keep the indoors warm. Therefore, the higher the R-value, the better the insulation.

For the most part, spray foam, cellulose and fiberglass have similar R-values. They are all great, time-tested materials and will provide a great insulating material. The only exception is that a polyurethane foam has nearly double the R-value of the above products. The price for polyfoam is also double.

Proper insulating methods are more important than the material itself.

Any insulation is only as good as the installation. So, it is very important that the installers fill every void. Gaps at the tops of the walls or bottoms of the walls greatly compromise the insulation's performance. In fact, the highest R-value materials will not provide much benefit if the installation was poor.

When renovating an existing house, this is the most common problem. The walls are closed cavities and installing insulation with zero gaps is nearly impossible. Make sure that the installer has many years of experience and comes with good recommendations.

Insulating your home is ultimately a matter of economics

It is true that people commonly threw newspapers and clothing into their wall systems during the early 1900s. The costs involved in heating homes were much lower, so insulation was not a great concern. Since the 1940s, heating fuel costs increased exponentially. Every decade since, insulation R-value recommendations have increased. It is important that one understands the cost savings when insulating their home.

Some homeowners think they need to have the highest R-values in their walls and at the same time never consider their attics. Since heat rises, it is best to increase the R-values in attic insulation then insulate the walls. With the new foam products, some homeowners also think that the more expensive the insulation, the better. When the fact is, the amount of insulation needed has to do with the climate and energy costs. It is better to insulate at current Department of Energy recommendations than insulate so heavily that there is no economic advantage. In fact, too much insulation can cause other problems that lead to costly fixes (i.e., restricted ventilation).

When considering insulating materials, homeowners should not overly concern themselves with the product as much as the cost of installing the product. As is always true with any remodeling or new build construction, multiple bids from experienced, recommended insulators will bring the greatest cost savings and insulating values.