Insulating a shed is not a piece of cake. It is particularly true if you are planning to turn it into, say, a home office or a food (perishable) storage.
On a good note, there are several insulation materials available in the market today. You can find insulation materials made of fiberglass, spray foam, and even mineral wool. However, while they all serve the same purpose, each of them performs differently in certain situations. As a result, whether it is for your shed or your house, it makes it difficult to decide which one is better or appropriate to use.
To help you, we enumerated a few shed insulation options as well as how they differ from one another.
Things to Consider When Insulating a Shed
Shed insulation is not a walk in the park. To efficiently heat proof a shed and other types of building, there are several important aspects that contractors and homeowners must take into consideration first. These factors and information are essential as they largely affect the type and amount of material you will need. And, accordingly, the overall cost of insulating a shed.
Here are the top four factors you should examine.
- The location’s standard weather. Not all places share the same “typical” weather. The city of New York, for example, is colder than Houston, Texas during winter. And for New York homeowners to follow the same insulation requirements used for Houston houses would be inappropriate and inefficient. The same goes with the place your shed is located. If the typical climate in your area is both extremely cold and hot, then it is best to fully insulate your shed. Accordingly, the weather can also significantly affect the number of materials you will need as well as the cost of both the materials and labor.
- The reason for insulation. Although it is known as storage for home tools and garden equipment, a backyard shed can have several purposes. Some use it as a workshop area, a summer house, a kid’s play den, a home office, and even (perishable) as food storage. Whatever it is you wish to turn your shed into, each situation requires a varying degree of insulation. For instance, if you are planning to turn your shed into food storage, then it is highly recommended to do full shed insulation. It means you need to thoroughly insulate all parts of the room, including the walls, roof, and even floors. The same applies if you are going to turn it into a home office or a kid’s play den.
On the other hand, if it is simply storage for home tools or discarded and unused appliances, then full insulation is not necessarily needed.
- The degree of insulation needed. You must use the right type of insulation material to efficiently heatproof your shed. To know what type of material is best for your shed, however, you need to get the U Value that is recommended for your home.
U Value, also known as thermal resistance, is the rate measure of a roof and wall’s heat loss. Contractors measure a house or a building’s U Value to calculate the most suitable insulation material (which I will explain further in the next section).
- The overall physical state of the shed. Last but not least is the physical condition of the room. The door, windows, and even the roof of the shed must be all intact and in good shape. Make sure that there are no cracks or gaps that may cause the heat to escape. If you found issues similar to what I mentioned, I suggest you fix them first before you insulate the room.
The R-Value of Insulation
Also known as R-factor, R-value is a rating given to insulation materials. It is essentially used to measure how well a material can resist the flow of heat. And the higher the R-value a material is, the greater its resistance to heat transfer. In other words, if an insulation material has a high R-value, then it has a good insulation effect and is most likely efficient to use in areas with extreme weather.
Do take note that a material’s R-value does not exactly equal to its thickness as well. In fact, when it comes to home insulation, thickness does not matter—but the R-value. Thus, it is extremely important to use a material with an R-value that is appropriate for your house.
Why Is R-Value Important?
There are several insulation materials available in the market today. Each material, depending on what it is made from, resists heat flow differently. In other words, they have varying R-Values.
Learning an insulation material’s R-Value is crucial as not all houses and buildings—and even the rooms inside a house—have a similar temperature. Some spaces are colder than others and may need a material with high thermal resistance or R-Value. Using a material that has the most fitting thermal resistance is much more efficient and can help you save energy in the long run.
4 Top Shed Insulation Options
Made using extremely fine glass fibers, fiberglass is a popular insulation material commonly found in homes. Essentially, its function is to reduce the speed of heat and cold as they flow and spread throughout the entire house—from walls, floor, and roof.
Fiberglass is best to use in spaces that need average temperatures such as the bedroom and the living room. And since it can reduce noise, it’s great to install in music and art studios.
A fiberglass’ thermal resistance varies depending on its thickness. An inch of fiberglass batt, for example, has an R-Value of 3.1 to 3.4. A three and a half-inch of fiberglass batt, on the other hand, has an R-value of 10.8 to 11.9 while the R-Value of a 12-inch batt ranges between 37.2 and 40.8.[source: Insulation R Value Chart – — (greatdayimprovements.com)]
The cost of installing fiberglass as an insulation material differs depending on various factors, including the size of the house or room, the location’s typical weather, as well as the area’s average labor pay. But on average, the cost of installing fiberglass for insulation ranges between $0.88 and $1.64 per square foot. And a 500 sq. ft. room can cost you around $300 to $600.
Pros and Cons
- Disadvantages. Fiberglass does not perform well in areas with high humidity and air exchange. And because it easily holds moisture, molds and mildew develop and thrive well in it.
Known as insulation and an air barrier material, spray foam is made by mixing polyol resin and isocyanate. Its function is to seal floors, walls, as well as ceiling cavities, to prevent air movement. It is typically and best used on small, hard-to-reach, and hard-to-fill areas like rim joists, crawl spaces, and spaces around light fixtures and electrical outlets.
Spray Foam R-Value
The thermal resistance of a spray foam depends on what type it is. An open-cell spray foam, for example, has an R-Value of 3.5 to 3.6 per inch while a closed cell spray foam has an R-Value of 6.0 to 6.5 per inch. 10-inch-thick open-cell spray foam has a thermal resistance of 35.0 to 36.0 while a closed-cell spray foam with the same thickness has a 60.0 to 65.0 R-Value.[source: Insulation R Value Chart – — (greatdayimprovements.com)]
The price of spray foam varies depending on the type. Open-cell spray foam, for instance, costs around $0.44 to $0.65 per square foot while the cost of closed-cell spray foam ranges between $1.00 and $1.50. When it comes to installation, the average amount of both spray foams range between $1.50 and $4.90.
Spray Foam Pros and Cons
- Perks. According to Home Advisor, spray foams work well against moisture. It has noise canceling effects too and even provides air sealing.
- Disadvantages. Spray foam comes with a high initial cost and takes longer to install compared to other insulation materials. It can cause eye irritation, skin, and even respiratory.
Blown-in cellulose is a type of insulation material that is either paper- or wood-based. It is thick and dense with a consistency similar to feathers. Using a mechanical tool, it is blown into empty spaces. Hence, its name. And just like other insulation products, it works as a barrier to slow down the flow of heat and cold throughout the house or building.
Blown-in Cellulose R-Value
Blown-in cellulose is divided into types; one is used specifically for attic and the other is for walls. And while they are the same type of material, their R-Value differs from one another. Blown-in cellulose for attic has a thermal resistance of 3.2 to 3.7 per inch while blown-in cellulose for walls has 3.8 to 3.9 per inch. A 10-inch thick blown-in cellulose for the attic, on the other hand, has an R-Value of 32.0 to 37.0 while blown-in cellulose for walls with the same thickness has an R-Value of 38.0 to 39.0.[source: Insulation R Value Chart – — (greatdayimprovements.com)]
In the US, the typical cost range homeowners spend for blown-in cellulose insulation is between $944 and $2,140 while the national average is $1,542. Its cost per square foot is around $1 to $1.50. In terms of installation, prepare to spend at least $40 to $70 per hour.
Blown-In Cellulose Pros and Cons
- Perks. Blow-in cellulose settles easily even in parts that have obstructions such as the attic. It is cheaper compared to fiberglass too, even though it has a higher R-Value. The material naturally repels insects too.
- Disadvantages. The only drawback the material has is that blown-in cellulose does not perform well in moisture-prone areas.
Mineral wool is a fiber-based insulation material that looks like fiberglass insulation and sheep’s wool. It is, however, denser, and stiffer compared to fiberglass and is made by combining slag and stone. It is commonly used in the piping industry not only due to its great thermal conductivity but also for its high resistance to heat.
Mineral Wool R-Value
The thermal resistance rate of mineral wool batt, as well as the one for attic and walls, are all different. Mineral wools for attic and walls, for instance, the R-Value is 3.1 to 4.0 per inch. On the other hand, mineral wool batt’s R-Value is 3.1 to 3.4 per inch.
The price of mineral wool depends on the type as well as the application. Mineral wool that is specifically for cavity wall insulation, for example, can cost you $10 to $15 per square meter. In general, however, the price ranges between $0.62 to $1.10 per square foot. Including labor cost and installation, expect to spend at least $2,200 to $5,900 for a 1000 square foot area.
Mineral Wool Pros and Cons
- Perks. Mineral wool is affordable. It has great thermal conductivity and can also reduce—if not cancel out—noise. It is also not flammable and can withstand moisture.
- Disadvantages. Constant contact with the material may cause skin irritation. It has lower heat storage capacity too.