What Is The R-Value of Spray Foam Insulation and What Do You Need to Know About It?

When you decide to insulate your house, you will see that spray foam insulation is one of the most effective ways to do it. R-value measures how efficient a material is at insulating your home, and spray foam insulation has high R-values. Especially closed-cell spray foam insulation, R-value per inch is higher because it is a rigid insulation type with its thick and dense form. If you would like to learn more about the R-value to make up your mind, you can find the information you are looking for below. Go ahead and read!

What is R-Value?

R-value stands for the thermal resistance value of insulation material. The goal of insulation is to decrease the conductive heat flow. Normally, heat flows from warmer places to cooler ones till the temperature is stabilized. The degree to which the insulation material can resist conductive heat flow is shown by its R-value. The higher the R-value an insulation material has, the more effective it is in resisting unwanted airflow. 

How Insulation Works?

The fundamental goal of insulation is to prevent or at least slow down the transfer of the heat from the heated places to the unheated places at your home or from inside your house to outside. Insulation works in this way by reducing conduction, convection, and radiation. 

Conduction

Conduction is the process of heat transmission through the contact of atoms or molecules of different materials when there is a temperature difference. Since particles are closer, conduction is seen more in solids and liquids when compared to gases, where particles are further away from each other. The energy transfer occurs as a result of the vibrations of the particles; no matter but energy is exchanged between the materials. 

The fundamental goal of insulation is to prevent or at least slow down the transfer of the heat from the heated places to the unheated ones at your home or from inside your house to outside. Insulation works in this way by reducing conduction, convection, and radiation. 

Convection

Convection takes place in gases and liquids. It refers to the flow of heat from one place to another promoted by the fluids’ movement. Fluids expand and become lighter when they are exposed to heat. Hence, the heated fluid rises and changes places with the cold fluid above. The heat source pushes the cold fluid down to be heated and rises. It means there is always a constant fluid flow from hot places to cooler ones. 

Radiation

Radiation is the transfer of heat by electromagnetic waves. It is called radiation when the infra-red radiant energy is transmitted from a hot location to a cooler one through the air or a vacuum. Radiant energy does not interact with a matter in between unless an object blocks its way. When an object blocks its path, that object absorbs energy to convert it to heat. The most known example of heat transfer via radiation is the radiant heat from the sun. Despite traveling millions of miles through space, the heat from the sun becomes effective once an object such as buildings, trees, people, or the earth blocks its path. 

In short, in all three mechanisms, heat moves from warmer to cooler places until the temperature is balanced. Insulation will provide you with the comfort of decreasing undesirable heat flow.

What Is the Amount of Insulation or R-Value You Need?

The R-Value needed to insulate your house properly depends on some factors. Depending on the climate of the location you live in, the required R-value changes. If you live in a cool place, you need an insulation type that has higher R-values. 

Likewise, the part of the house you would like to insulate affects the needed R-value. Insulating the exterior walls or windows of the house requires insulation with less R-value. In contrast, insulating attic, crawl spaces, basement walls, ceilings and garage doors with a higher R-value will be proper. While determining the amount of insulation required, you need to measure the height and length of the places you want to insulate. 

R-Value Chart for the USA

You do not necessarily need to insulate your house using the material with the highest R-value. The R-value that will best fit your house is determined by the USA climate zone you live. Find your house’s zone on the map, and then see the R-value insulation chart to find out what level of R-value your insulation should have. For example, if you have a closed-cell insulation that has an R-value of R-5 per inch of thickness, you will need a depth of 4-inches of this insulation installed in your 2X6 wall  to reach R-20  if you live in Zones 4 or 5.  

What Is the Foam Insulation Spray R-Value

There are two types of foam insulation: open-cell foam and closed-cell foam. Both open-cell and closed-cell are effective types of insulation when appropriately applied. However, they have different uses. Also, the R-value of spray foam insulation depends on its type.

Closed-Cell Foam R-Value

Spray foam comprises two chemicals that immediately expand after contacting each other. When the chemicals expand, bubbles are formed. Closed-cell foam is the type of insulation where interconnected closed holes are built during the expansion. For that reason, closed-cell foam is denser than open-cell foam, and the denser the foam, the higher the R-value is. Closed-cell foam has an R-value in the range of 5.6-8. That value is much higher when compared to other types of insulation such as fiberglass, cellulose, or even open-cell foam.

Open-Cell Foam R-Value

Unlike the closed-cell foam, which comprises co-dependent closed bubbles, open-cell foam is made of cells that are not embedded during the expansion of the chemicals it is made from. Open-cell foam is porous and not as dense as closed-cell foam. For that reason, its R-value is less than the closed-cell foam. The R-value of open-cell foam insulation is around 3,5 per inch. Although it is not the right type of insulation in places with extreme weather conditions, open-cell foam is perfect for reaching nooks and crannies in a house.  

Conclusion

In short, depending on the house's location, the climate conditions, the insulation goals, your choice of spray foam type, and the R-value required may change. Closed-cell foam offers a higher R-value than other types of insulation. If you want to insulate your home, contact us now to learn more about the right spray foam and R-value you need.