How Long Does Blown In Cellulose Insulation Last

How Long Does Blown In Cellulose Insulation Last?

Installing new insulation or upgrading existing insulation is a sizeable project so it is natural to want to know how long the blown in cellulose insulation will last.

Blown in cellulose insulation will last anywhere from 20 to 30 years under ideal conditions. There are many factors that affect the lifespan of blown in cellulose which is why you need to make sure that it is installed professionally from the beginning.

Factors Affecting Life Span of Blown in Cellulose Insulation

Attic Insulation Toronto has decade’s long experience in the industry and has amassed a lot of knowledge and experience to overcome these potential problems.

Existing Air Leaks

The process of installing blown-in cellulose insulation properly begins long before the material itself is even fed into the machine. Cellulose is effective in regulating heat transfer via conduction but not so much where there are direct air leaks. Installing the cellulose before first sealing all the air leaks means that the air continues to flow. These air leaks are also extremely difficult to detect once the insulation is installed. This situation limits the effectiveness of the insulation as far as energy efficiency is concerned.

This isn’t a problem as long as the air leaks are identified in advance and sealed appropriately. Our technicians have the expertise to perform this step satisfactorily which can be hard to do without the proper training and experience. This one of the many reasons we discourage DIY installation.


Blown in cellulose is a fluffy material that settles with time. In fact, cellulose has the highest rate of settling rates at anywhere between 13 and 20 percent after installation. This settling continues over the weeks, months and years after installation and can cause severe energy efficiency issues if not addressed properly during the insulation.

Fortunately, this is an easy problem to overcome by simply adding more insulation than is needed to account for the settling. Despite cellulose high settling rate, it still offers a higher R-value per inch of thickness than the alternatives. This settling is simply not a good enough reason not to install cellulose.


Cellulose blown in insulation is primarily made from recycled newsprint and therefore more susceptible to moisture damage. A major leak in the attic can seriously affect the material’s ability to do its job properly.

This insulation, however, has great fire and water resistant qualities so save for a major leak, you shouldn’t be too concerned about moisture damage. Still, you need to regularly check your roof and attic for moisture problems especially after a storm or harsh weather.

Our technicians do all they can to make sure that the attic is sufficiently water and moisture proof before installation and may make additional recommendations depending on the state of the attic.

Does Cellulose Insulation Settle Over Time?

Cellulose insulation is one of the best types due to its breathability and greener alternatives to traditional fiberglass insulation. Cellulose insulation utilizes recycled paper products that are treated to be repellent to pests and even to safeguard against fires, so it is only natural that this insulation type is becoming the most popular for attic insulation. One factor of this type of insulation that gets negative mentions is its propensity to settle over time, rendering its insulation properties ineffective.

Not all cellulose insulation settles within attics and a lot of the determining factor behind this has to do with how the insulation was applied in the first place. If cellulose insulation has settled, you have likely discovered that this is likely the case due to an increase in your home’s energy output. What can cause cellulose insulation is predominantly the process of choosing to have the insulation blown in. Due to the insulation being exposed to the air, it is only natural that settling will occur, which will create gaps in the areas needing to be insulated.

To avoid this potential problem, you should request that the cellulose insulation covering your attic floor be blown in at a much higher thickness than what is traditionally applied. This will give the insulation a thickness that can prevent any air leakages. If the blown in insulation is laid to light, the material can easily begin to settle and even scatter over a period of time. If you feel that your cellulose insulation has begun to settle, then you may want to contact an attic insulation specialist for a consultation to determine if this is the case. A specialist will be able to determine if there is a fix to the situation, or if the insulation should be removed and reapplied to an acceptable thickness.

Is Blown in Cellulose Insulation Good?

Cellulose insulation in and of itself is always a good option when deciding the type of insulation to apply to your attic. This type of insulation is more pliable and much better at retaining an acceptable R-value in your overall attic insulation performance. With this in mind, having this type of insulation blown in may not be the best option depending on if you have it blown in correctly. Blown in cellulose insulation when applied at a thick enough width can last for years; this material is also less susceptible to mold and mildew.

If you want to have your cellulose insulation blown in, you should always consult with a professional service to ensure that the material is blown in at a density to avoid possible settling over time, which can be a problem with cellulose insulation. To ensure that your insulation is applied properly, always make sure that you buy enough cellulose insulation to provide a second coating on top of the first coating.

This insulation type will provide an overall better insulation performance than other insulation types but preventing the settling of the material is an absolute must during the application process.

Is Cellulose Insulation Harmful?

Apart from its propensity to settle, there is very little to find in cellulose insulation to label it harmful. This insulation type provides an incredibly long-lasting performance with less harmful properties of insulation types as they age. With that said, cellulose insulation does have a couple of drawbacks that should be kept in mind. Firstly, it is crucial to keep cellulose insulation 100% dry at all times. When this material becomes wet, it is incredibly hard for it to dry out. Additionally, constant moisture will waterlog the cellulose, causing it to settle as time goes by.

Cellulose insulation can also cause potential health risks if it remains wet. The chemicals applied to cellulose insulation are used to prevent pests and rodents from nesting with the material, in addition to preventing fires from engulfing the material and becoming worse. Once these chemicals are saturated with water, they can release ammonium sulfate within the air of the home, which can cause breathing problems as well as overall malaise and ill-health. A professional cellulose insulation installer is trained to ensure that there are no moisture leaks in the attic.

Always ensure that your cellulose insulation is odorless before having it installed. If there is a strong odor, this is a sign that the chemicals were applied to oversaturation. Also, be sure to have your cellulose insulation installed far away from any light sources which can cause the material to catch fire. A clear way to ensure that there may be a problem with your freshly installed cellulose insulation, always be on the lookout for odors that smell strongly of chemicals, this is likely a sign that the cellulose insulation has been moistened.

When in doubt, consult a professional service to either install or inspect your cellulose insulation for malfunctions. Call us now: 647-931-6385

Why You Should Have Blown In Cellulose Insulation Installed Professionally

Watching experts at work installing blown-in cellulose may look like a simple job and often it is. There are many obvious and subtle considerations that may escape the layman including heat transfer through walls, types of lights in the attic space, whether or not the chimney is properly insulated (if it passes through the attic) and many more considerations. The installation itself is the simple part. An expert’s wealth of knowledge, experience and equipment is irreplaceable if you want to get the most energy efficiency and a long life out of your insulation.

Attic Insulation Toronto guarantees that the installation is done right from the very beginning and you can begin to recoup your investment in energy savings within the shortest time possible.  Call us now: 647-931-6385

Article Updated: January 29, 2020