4×8 Styrofoam Insulation Sheets


4×8 Styrofoam insulation sheets are perfect for warming up certain parts of the house during the cold winter months and keeping it cool during the hot summer months. Properly installed Styrofoam insulation helps to minimize energy use, saving the owner money. It also provides for more uniform temperature throughout the entire house, from the exterior walls to the ceilings to the windows, and finally to the interior walls. A more uniform temperature throughout the entire building provides a more comfortable atmosphere for everyone in the family. Moreover, 4×8 sheets of Styrofoam do not have a recurring expenses compared to air conditioners or heaters. They require very low maintenance and the insulation they provide is usually considered permanent.

rigid insulation

The R-Value of Insulation

Keep in mind that the 4×8 Styrofoam insulation sheets come with varied thickness, anywhere from ½ an inch to 5 inches. Obviously, the thicker the insulation sheets, the better it is at retaining heat. The R-value of insulation refers to the measure of thermal resistance. The R-value of insulation depends on a host of factors, which include the thickness, the material, and its ability to reflect sunlight. The purpose of the R-value is to prevent consumers from being misled by fake or misleading advertising claims. Therefore, it is in your best interest to pay attention to the R-Value of insulation because it’ll give you a specific measurement of how well the Styrofoam insulation sheets work in retaining heat.

Tips on installing Insulation

Avoid direct sunlight when installing your 4×8 Styrofoam insulation sheets. Overtime, sunlight can damage the insulation and diminish its overall effectiveness.
If you are insulating your roof, make sure to protect the insulation by coating it with tar, acrylic or silicon.

Avoid moisture buildup on the insulations, which can lead to the growth of mold. During the summer, outside hot air and inside cool air can lead to condensation causing moisture to form on the insulation. Just think of a cold glass of coke on a hot summer day. If you wait enough, you can see all the moisture that forms on the outside of the cup. The same can happen to your house. You can prevent moisture buildup by installing a vapor diffusion retarder on the warmest side of the wall.

Avoid insect problems by placing insecticide around the area you plan to install insulation. Although insects do not eat Styrofoam, they can easily borrow through it, diminishing its R-Value. A lot of manufacturers put insecticide inside their insulation to prevent insects from borrowing through them. When purchasing your Styrofoam insulation 4×8 sheets, make sure to check if they are built to keep away pesky insects.


There are many companies that produce 4×8 styrofoam insulation sheets. Owens Cornings, GREAT STUFF PRO, Enerflex and Johns Manville are the most well known. Your best bet to find the best Styrofoam insulation sheets is at your local Home Depot or Lowe’s, where you’ll find tons of options as well as assistance to help install it at your home for a small fee, which saves a lot of time and headache.


The great thing about Styrofoam insulation sheets is that it’s cheap and lasts a lifetime if properly installed. In the long-run, this can save you hundreds of dollars on your energy bill.

If you are thinking about installing Styrofoam insulation 4×8 sheets, I suggest you do it right away.