R49 Insulation Thickness Guide

Ever stop and wonder “Why is my electric bill so high?”? Unfortunately, you are not alone. Thousands of Americans suffer from exceedingly high energy bills and cannot seem to find the source. Well, we’re here today to offer you one: your insulation. Homes that lack insulation are very susceptible to suffering from high energy bills as their home is unprotected from mildew, humidity, and the outside elements. However, not all insulation is created equal. Blown-in insulation is an excellent, cost-effective solution. However, what does blown-in insulation cost? It all depends on the insulation type and thickness you choose to install. We’re going to discuss the detailed composition of insulation and its direct correlation with what you choose for your home. We will specifically be discussing R49 insulation thickness and the different materials offered in this particular thickness of R-value insulation. 

R-Value: What is It? 

All insulation has an R-value. But what does that mean? An R-value is a number representing the temperature difference required to conduct 1 BTU of heat per hour through an area of 1 square foot per inch thick. With an increase in insulation thickness, the R-value increases, as well. BTU is short for British Thermal Units. It measures the quantity of heat required to raise the temperature 1 degree Fahrenheit when the water’s temperature is at its greatest density (39 degrees Fahrenheit). 

R-49 Insulation Thickness: What is It?

Given what we now know about R-Value, what about R49 insulation thickness? R49 insulation merely means that it requires 49 degrees of temperature difference to conduct one BTU of heat per square foot of area. However, not all R49 insulation thickness is created equal. It depends on the type of insulation material used. Therefore, the type of insulation you choose to use in your home will require a certain number of inches to be installed to reach R49 thickness. The price, therefore, will depend significantly on the material type chosen. These are the required inches required: 

Open Cell Spray Foam14.5 inches to reach R49 Thickness
Closed Cell Spray Foam7-8 inches to reach R49 Thickness
Fiberglass Batt14 inches to reach R49 Thickness
Blown-In Fiberglass16.25 inches to reach R49 Thickness
Blown-In Rockwool16 inches to reach R49 Thickness
Rockwool Batt14.25 inches to reach R49 Thickness
Foam Board Insulation10 inches to reach R49 Thickness

R49 is capable of being used in all climate zones, due to its high heat resistance. It is most often used in homes located in climate zones 5 to 8 in the United States but is safe to use throughout the country. 

The type of material chosen provides certain benefits and setbacks depending on your home and its capabilities. We will discuss each type of material mentioned above in detail. 

Spray Foam Insulation

There are two types of spray foam insulation: closed cell and open cell. Closed cell insulation for R49 insulation thickness requires 7 to 8 inches, while open cell requires 14.5 inches to reach R49 insulation thickness. 

Closed Cell Spray Foam 

Closed cell spray foam insulation consists of tiny bubbles that, once sprayed, traps air. The trapped air provides an additional barrier of insulation. They have a very low thermal conductivity potential and are incredibly fire-resistant. Out of all the material options, closed cell spray foam insulation requires the least amount of thickness to achieve R49 insulation thickness. The R-value is about 6.5 per inch. Therefore, to achieve R49 insulation thickness, about 7 to 8 inches of insulation must be sprayed. For those who desire a drawn out math calculation: 

49     /      6.5     =     7.539 inches

    [    (R-49)   /   R-value  =    required thickness ]

Due to a smaller requirement of thickness, closed cell spray foam insulation is most effective in areas that are smaller or do not have room for additional inches of insulation. 

Open Cell Spray Foam 

Much like closed cell spray foam, the bubbles in the spray foam trap the air and create a barrier of insulation. However, unlike closed cell insulation, open cell spray foam cells are not encapsulated. Thus, it conducts heat faster. The R-value of open cell is 3.5 per inch. Therefore to achieve R49 insulation thickness, about 14.5 inches of insulation is required. (49/3.5=14). Open cell foam insulation is more flexible and can therefore be utilized in more difficult-to-reach places, such as ceilings and roofs. 

Batt Insulation

Compared to blown-in insulation, batt insulation has a greater R-value. Batt insulation comes in three different types: fiberglass, rockwool, and cellulose insulation. R49 insulation thickness ranges depending on whether you use fiberglass or rockwool insulation. 

Fiberglass Batt Insulation

Fiberglass batt insulation has an R-value of 3.6 to 5 per inch. To achieve R49 insulation thickness, fiberglass batt insulation needs to be around 9.5 to 14 inches thick. Fiberglass batt insulation is able to be installed anywhere in the home. 

Rockwool Batt Insulation

Rockwool batt insulation consists of melted-down rock and slab. Rockwool insulation has a very similar R-value to fiberglass batt insulation coming in around 2.8 to 4.4 per inch. In order to achieve R49 insulation thickness, it requires about 14.5 inches of rockwool insulation. 

Blown-In Insulation 

Blown-in insulation is yet another option to use in your home. Blown-in insulation is one of the cheaper and faster options, as it is installed with loose-leaf insulation and literally blown into the open space. Blown-in insulation is able to be blown into tight corners and other hard-to-reach places that rolled-out batt insulation cannot reach. Blown-in insulation costs vary on the type of blown-in insulation material used. 

Blown-in Fiberglass Insulation

Blown-in fiberglass insulation is loose-leaf fiberglass insulation installed via a long hose. As mentioned above, this is a great option for hard-to-reach places in your attic. Due to its installation process and thin, small pieces, the R-value of blown-in insulation is less than batt insulation. The R-value for blown-in fiberglass insulation has an R-value of 3.2. Therefore, to achieve R49 insulation thickness, 16.25 inches of blown-in fiberglass insulation is needed. 

Blown-in Rockwool Insulation 

Blown-in rockwool insulation is installed a bit differently than blown-in fiberglass insulation. Blown-in rockwool insulation is installed using a vacuum. The vacuum will first suck in all the air inside the wall and then replace it with the insulation material. Blown-in rockwool insulation, due to its greater capabilities of heat resistance, is less dense. Its R-value is 3 per inch. It, therefore, requires 16 inches of blown-in rockwool insulation to reach R49 insulation thickness. 

Foam Board Insulation

Hard-backed foam board insulation is yet another option to use in your attic as a barrier. It has great heat resistance capabilities and is extremely durable and thick. Foam board insulation has an R-value of 5, requiring only 10 inches of thickness to achieve R49 insulation thickness. 

What Is Right for You? 

R49 Insulation Thickness is one of many thicknesses that you could use in your attic and additional spaces to insulate and protect against the elements. The materials to comprise such a thickness, however, are many. Our Specialists are here to help you determine the best thickness, as well as materials to suit your home and your specific needs. In the meantime, however, here is a calculator to begin estimating the required amount of insulation required, as you investigate the different options. From blown-in insulation to foam boards, we recognize that each type of material comes with different costs. Blown-in insulation costs with a vacuum are less than those installed by hand. All of these, however, assist in figuring out why your electric bill is so high. Give us a call today. We’d be more than happy to help! 

Good Home Insulation

We’re committed to saving you money and safely keeping your family comfortable all seasons of the year.

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