Professional in full foam insulation installation gear adding spray foam insulation in an attic

Spray Foam Insulation Vs Cellulose: What’s Better For Your Home

Spray foam insulation and cellulose insulation both improve your home's energy performance and comfort by different means. There are many benefits to spray foam insulation, but the advantages of cellulose are often overlooked. Here's a side-by-side review that breaks down the pros and cons of each.

What is Foam Insulation

Insulation is any material used to disrupt the natural flow of energy, allowing for the constant maintenance of temperature in a home. It blocks additional heat from entering the house when it is hot outside and keeps the warmth inside when it’s cold.

The way insulation is rated is by its R-value. In terms of insulation, an R-value measures how resistant the insulation is to heat flow. R-value determination is reliant on insulation type, thickness, and density.

Typically, a higher R-value indicates better climate control ability and energy efficiency; however, the Department of Energy recommends choosing the correct insulation level based on your region’s specific climate needs.

The good news is that the majority of homes already have some amount of insulation installed.

The most common places to find insulation would be:

  • the attic,
  • any floors above basements or crawl spaces, and
  • inside the exterior walls of your home.

Exterior walls, attics, basements, and crawl spaces are also the most effective areas of a home to add additional insulation to control your indoor air quality and climate better.

Regardless of the home’s age, it is always a good idea to see if there are ways to improve energy efficiency. According to the North American Insulation Manufacturers Association, 90 percent of homes in the United States do not have adequate insulation.

It is a good idea to determine if your home has insulation material and where it is installed. If your home has insulation, it is a good idea to determine the type of insulation:

  • It could be fiberglass bat or loose-fill fiberglass insulation.
  • Cellulose insulation, spray foam, or foam board insulation are also pretty standard in more modern homes.
  • Vermiculite insulation (Caution: homes built before 1980 with vermiculite insulation in the attic should be tested for asbestos by a licensed professional), as well as a few others not mentioned here.

Once you have discovered the insulation type in your home, compare that to the current industry standards to see if anything needs to be updated or added.

Next, you will need to calculate how much insulation you will need. To do this, measure the depth of your current insulation. The industry-standard measurement is R-38, with the minimum thickness being 12 inches. So, suppose your insulation is only 4 inches deep. In that case, you will have to add at least 8 inches of insulation to bring it to the correct rating (this is simply a general standard and is not the same for every geographical locale).

When the time comes to buy insulation, take the location and current state of the insulation in your home into consideration. If you are doing it yourself, consider if you need to rent tools or if you need to bring a professional in to assist.

After all of that has been established, it is time to learn about the differences between spray foam insulation and cellulose insulation.

The good news is that there are various types of insulation, and we will be discussing the different aspects of each of them here.

Residential Insulation Thermal Resistance or R-Value Calculator

If you are in the process of building or renovating a home, chances are you have thought to yourself, how much insulation do I need to satisfy the thermal resistance values determined by each state’s ecology and weather for the different parts of a home.

If so, you are exactly where you need to be, as the calculator below will give you a good idea of how thick your insulation should be in order to satisfy local residential heat resistance requirements when building or renovating a home.

Spray Foam Insulation

A spray foam insulation kit is a quick and easy way to achieve energy efficiency in your home.

Spray foam insulation is a liquid latex or spray polyurethane foam that typically comes in a can for small jobs. It is sprayed through gaps into sections needing insulation and then immediately expands and hardens, instantly filling the space.

For larger jobs using spray foam insulation, spray foam installers will spray everything into place with larger equipment and a different type of spray foam; closed-cell spray foam.

Closed-cell spray foam insulation is denser, resulting in a higher R-value. The R-value of closed-cell foam is approximately R-6.2 per inch of thickness, almost double that of open-cell spray foam.

Because of this huge difference, closed-cell spray foam is pricier than open-cell foam.

Some well-reviewed brands are Froth-Pak, Tiger Foam, Great Stuff Pro Gun Foam, and JM Spray Foam Products.

Advantages of Spray Foam Insulation

Because it comes in a can, you can use this insulation to increase the resistance rating of areas inaccessible to other insulating methods. By merely spraying, similar to a can of spray paint, you can reach oddly-shaped areas around doors, windows, and vents.

Along with this, spray foam insulation sets very quickly. It can then be shaped, trimmed, painted, or stained with ease! With a couple of cans and some time, you can reduce energy costs, keep pests out, and make your home more comfortable by air sealing open gaps and cracks.

Buildings treated with spray foam insulation insulate as much as 50% better than the other products out there.

Disadvantages of Spray Foam Insulation

One major disadvantage of using spray foam is the impact that it has on the environment. This type of residential insulation is customarily made using hydrofluorocarbon (HFC) blowing agents that have been known to contribute to global warming.

Hydrofluorocarbons are said to be harder on the environment than elevated levels of carbon dioxide. In the United States, HFCs are scheduled to phase out in January 2021, but this may be delayed due to the global Corona Virus pandemic.

Another disadvantage is the process of curing the insulation. While curing, spray foam emits a toxic gas that can cause blurred vision and trouble breathing.

Using a full face mask and respiratory protection is a must. The spray foam contains isocyanates, potent irritants to the eyes, gastrointestinal, and respiratory tracts. Any direct skin contact with isocyanates can cause inflammation and rashes.

Cellulose Insulation

Cellulose insulation is an entirely different type of insulation option. The dry cellulose insulation is made from recycled paper products and then treated with boric acid (flame retardant).

Cellulose insulation is generally used in wall and roof cavities to increase energy efficiency, reduce noise, and keep insects out. Dry cellulose is added to older homes by blowing it into channels of set areas inside the walls.

This is called loose-fill insulation and can also be installed in new homes by using a type of netting that is removed when the actual walls are put in place to hold it in.

With loose-fill insulation, it has been known that the initial form of application settles at about 30-40%, meaning that the R-value will shift numbers over time with every different project.

It is important to read the instructions entirely and reference any charts associated with achieving the desired R-value. Experienced installers may dense-pack the insulation to help mitigate some of the insulation settlings. This can only be done in a closed cavity by applying pressure on that cavity to ensure there are no insulation gaps.

Another type of cellulose insulation is called spray-applied cellulose. Otherwise known as wet-spray cellulose, it is often used for new wall construction.

The critical difference from dry cellulose is simply being wet down with water and adding some moisture retardant to prevent mold.

Wet-spray cellulose allows for the cellulose to be used without a closed container to hold it in. Also, wet spray allows for better sealing and eliminates settling issues common to dry cellulose insulation.

As a side note, the wall that is being treated must be dry for 24 hours before applying the wet-spray cellulose.

Stabilized cellulose is a third type of cellulose insulation that is available. Commonly used in the attic or roof, it is applied with a small amount of adhesive to reduce settling and decrease the total amount needed. This option is used mostly for roofs, attics, and ceilings because it is an approved method for roofs with a 5:12 slope.

The last main type of cellulose insulation is known as low-dust cellulose. Because of the large amounts of dust that regular cellulose insulation produces, heavy-duty masks and other personal protective equipment may be needed.

Low-dust cellulose has a small percentage of oil or dust dampener within it, causing only simple masks to be required. This option is the best for people sensitive to newsprint or paper dust, even though new dust won’t be created after installation.

Advantages of Cellulose Insulation

With the highest recycled content of any insulation available, cellulose is considered the most “environmentally friendly” type of insulation. It is commonly composed of about 75-85% recycled paper fiber, usually newspapers.

The other constituent portion is made up of a fire retardant to avoid any future disasters. Unlike foam insulations, which use HFC blowing agents with a global warming potential higher than carbon dioxide, OSHA states that cellulose insulation installation only requires a dust mask to install in the home.

Another advantage that cellulose entails is annual savings. It is important to note that yearly costs will change due to home performance, climate, heat/cooling usage, and the rest of the building’s airtightness.

One installer claimed that cellulose installation could save homeowners 20-50% off their utility bills than other insulation types.

Along with lowering energy bills, cellulose insulation has been known to reduce sound traveling through walls and between home levels.

By providing both mass and damping and being three times denser than fiberglass, cellulose improves sound reduction compared with fiberglass.

Lastly, the insulation’s borate treatment gives it the highest (Class I) fire safety rating, and safety is so important when it comes to the structure of your home.

Disadvantages of Cellulose Insulation

One key disadvantage to cellulose insulation is the access to installation expertise and building codes. Because of modern building codes, some homeowners may not have the updated regulations on installing it properly.

Homeowners and professionals alike should call the city before installation to ensure it is an approved activity.

An expert in cellulose insulation would understand how to pack it correctly, apply partially wet cellulose on sloped surfaces best, and how long it requires to dry.

It is essential when performing any work on the roof to inform someone what you are doing and that you will be on your roof for a time. This is for obvious safety reasons should anything unfortunate happen while on top of your home.

There have also been a few cases where there is an increased mold infestation inside buildings that used the wet-spray method. Combined with a vapor barrier, this can become a huge issue if not taken care of properly.

Wrapping up With Some Insulation Tips and Tricks

Here are a couple of final, general tips when it comes to installing more insulation in your home:

  • It is recommended to insulate your attic, outer walls, and crawl spaces first because they have the most potential for heat transfer.
  • Another tip is to insulate water heaters to prevent excess heat loss. Search for insulation pre-cut jackets of at least R-8. This can save you about 4-9% of heating costs.
  • There are also a few other insulation types, such as fiberglass insulation, foam boards, and glass wool. Always ensure you do the proper research before deciding on the insulation to install or add to your home.

A properly insulated home will make you feel safe and ready for any weather.