Fiberglass Insulation vs Foam Insulation

Insulation is a part of your home that is rarely seen or discussed, but in actuality is vastly important.  Properly insulating your South Texas home can keep your utility bill low which is great for your wallet and the environment.  Modern insulation can be made from just about anything including newspaper, cotton, wool, and artificial materials such as chemical foams.  More environmentally friendly options are on the market too, recycled-content insulation and formaldehyde-free are just a few of those available.  If you haven’t read our general information about insulation installation, you can read it here.


Practically everyone can recognize fiberglass insulation, it’s that pink stuff your parents told you to never touch and were paranoid about you breathing around it without a mask.  They weren’t wrong!  Fiberglass installation is best left to the professional as the glass fibers of which it is made, can be broken off and inhaled which can lead to lung damage.  The traditional form of fiberglass insulation is made with phenol-formaldehyde which is toxic, but recently, manufacturers have begun to make fiberglass without formaldehyde as well as using 30-40 percent recycled glass.

Fiberglass works as insulation because the tiny glass fibers trap bubbles of air that slow the transfer of heat.  Because it is widely used across the USA, installation is cheap and it can be easily purchased.  It is prone to air leakage, which makes the R-Value lower and it is also flammable.

Foam Insulation

Spray foam insulation is one of the most effective insulations that you can choose for your home, it’s a liquid that is poured or sprayed into a wall cavity where it will expand and harden.  The R-Value of spray foam depends on the type that you choose; the traditional form uses polyurethane (a type of plastic) as well as chlorofluorocarbons which has been shown to damage the ozone.  This type of spray foam has an R-Value of 6-7 because of its density.

The newer forms of spray foam are made from vegetable-bases such as corn fructose and soy and use water, hydrofluorocarbons, or carbon dioxide in place of chlorofluorocarbons.  Greener foam comes with a decrease in R-Value: 3.2 – 4.5 per inch.  Spray foam must be installed by professionals, and some types are made only for new wall construction.