Pros And Cons Of Blown-In Cellulose

If you’re considering blown-in cellulose insulation, you want to know if you’re making a wise investment decision. Every product has its benefits and drawbacks, and cellulose insulation is no different. Will blown-in cellulose work for the project you have in mind? Is this the right choice for your budget and lifestyle?

South Central Services has insulated hundreds of new and existing homes. Our team installs both blown-in cellulose and spray foam insulation. While we often favor spray foam for its superior performance, blown-in cellulose has its place among insulation options.

By the end of this article, you will know:

• The benefits of using blown-in cellulose
• The drawbacks to using blown-in cellulose
• Whether or not blown-in cellulose is right for you

What Is Blown-In Cellulose?

Blown-in cellulose is a type of cellulose insulation. Blown-in cellulose is just what it sounds like: loose-fill cellulose particles scattered by a blowing machine.

Fiberglass is another type of blown-in insulation. While the application of these two products is essentially the same, the products are quite different.

Another type of cellulose insulation is dense pack cellulose. Dense pack insulation is tightly packed into building cavities. While the two insulations are related, this article will focus specifically on blown-in cellulose insulation.

Pros Of Blown-In Cellulose Insulation

Why do homeowners choose blown-in cellulose insulation for their homes? There are several selling features that draw homeowners to blown-in cellulose.

1. Environmental friendliness
2. Effective conductive insulator
3. DIY capabilities
4. Insulation safety

Let’s examine each of these benefits in more detail.

1. Blown-In Cellulose Is Relatively Eco-Friendly.

Since blown-in cellulose is composed mainly of recycled print materials. How much of the cellulose is recycled depends on the manufacturer. One cellulose manufacturer, Nu-Wool, claims that 86% of their product is recycled content. As a general rule, cellulose should be made up of at least 70% recycled material.

When it comes to recycled content, cellulose cannot be beaten. Spray foam insulation is not made of recycled materials, and fiberglass may contain 60% recycled content at most.

One consideration for the environmentally friendliness of blown-in cellulose is the decline in print media. When cellulose insulation became popular in the 1950s, 60s, and 70s, newspapers were significantly more common. The amount of recycled material may decrease as recyclable print materials become less popular.

2. Blown-In Cellulose Prevents Conductive Heat Transfer.

Like all other insulation materials, blown-in cellulose is measured by a metric called R-value. R-value, or resistance value, is the measurement of how well a material resists conductive heat transfer. The higher the R-value, the better a material does with insulating.

Blown-in cellulose can be installed to any R-value, but is usually installed between R-19 and R-60. For our climate zone, attic applications usually need an R-value of R-49. Attics take on a great deal of heat from the sun in the summer.

3. Blown-In Cellulose Can Be Installed As A DIY.

Not all insulations can be installed DIY. Some products, like spray foam insulation, are too complex for a homeowner to tackle on their own successfully.

Another popular attic insulation is fiberglass batts. Batt insulation can also be installed DIY but can be tricky to install correctly. To maximize performance, fiberglass batts must fit snugly inside cavities without gaps. Purchasing the wrong size of batts will lead to gaps.

Blown-in insulation is easier to install as a DIY. While you will have to rent a separate blowing machine, the most math you’ll need to do is determining how many bags you need to meet the necessary R-value for your attic. Installing blown-in cellulose yourself will also be time-consuming, but it is technically possible. There are also fewer risks to DIY blown-in compared to DIY spray foam.

4. Blown-In Cellulose Is Safe To Touch.

One other benefit of blown-in cellulose is the safety of its material. When interacting with the insulation, it is wise to wear personal protective equipment (PPE) like safety glasses, gloves, and a mask. However, this PPE is only to protect you from getting dust on your hands or in your eyes and lungs.

Other blown-in insulations, like fiberglass, are less safe to touch. Fiberglass insulation is composed of thin glass and plastic fibers. This glass can become airborne or give you contact dermatitis if you touch the insulation. When dealing with blown-in fiberglass, PPE becomes much more important.

Cons Of Blown-In Cellulose Insulation

While blown-in cellulose has some clear benefits, there are a few drawbacks to using cellulose. Some of these include:

1. Limited applications
2. Lack of air-seal
3. Cost
4. Settling

Let’s examine each of these drawbacks in more detail.

1. Blown-In Cellulose Has Limited Applications.

As a blown insulation, cellulose can only be used for attic floors. When you consider all the areas of a home that need insulation, blown-in cellulose is somewhat restricted.

Blown-in cellulose can be installed in walls and rafters through the dense pack method. However, dense pack cellulose is not a DIY method like blown-in cellulose.

2. Blown-In Cellulose Does Not Offer An Airtight Seal.

As an insulation, blown-in cellulose must have a reasonable R-value. R-value is the traditional measurement of insulating power. However, there are two methods of heat transfer that R-value doesn’t measure: conduction and radiation.

Blown-in cellulose cannot stop conductive or radiant heat transfer. Air can easily pass through blown-in insulation, letting heat pass along with it. Without a separate airtight seal, blown-in cellulose will only protect from one of three methods of heat transfer.

When we insulate an attic with blown-in cellulose, we combat this weakness with an air-seal on the attic floor. By stopping air leakage, we can maximize the performance of the blown-in.

3. R-Value To R-Value, Blown-In Cellulose Is Equally As Affordable As Other Insulation Solutions.

When blown-in cellulose first hit the market, it was an affordable insulation option. There were plenty of recyclable print materials to create cellulose insulation. As digital media has replaced print media, fewer materials are available.

Cellulose is still relatively budget-friendly, especially when compared to a premium product like spray foam. However, to meet an R-value of R-49 in an attic, blown-in cellulose pricing is still between $1.70 and $4.00 per square foot.

When paired with an airtight seal, blown-in cellulose is not as inexpensive as fiberglass batt insulation.

4. Blown-In Cellulose Will Settle Over Time.

Blown-in products settle over time. Blown-in insulation is loose fill sitting on top of itself. The top layer compresses the layers below it. As time passes, the insulation will naturally weigh on itself.

Settling occurs much faster if the insulation is disrupted. If you go to your attic and touch the cellulose, the particles will redistribute and settle through any open spaces.

Blown-in cellulose can deliver its expected R-value for many years when left undisturbed. However, cellulose insulation will eventually need to be topped off to offer that R-value.

The Bottom Line About Blown-In Cellulose Insulation

Blown-in cellulose is an excellent option for attic insulation when spray foam is out of budget. Cellulose is safe to touch and is comprised of mostly recycled materials. On its own, blown-in cellulose can deliver an appropriate R-value for attics. When paired with an airtight seal, cellulose becomes more expensive but also stops all forms of heat transfer.

Now that you understand the benefits and drawbacks of blown-in cellulose, your next step is to:

• Discover if blown-in cellulose qualifies for any tax credits
• Estimate the cost of blown-in cellulose for your attic
• Compare the best insulations for attics