fiberglass insulation installed in the walls and ceiling of an attic

How Long Does Fiberglass Insulation Last?

Fiberglass insulation is a durable and long-lasting solution for sealing your home. However, it doesn’t last forever, and certain conditions can reduce its effectiveness and lifespan.

At REenergizeCO, we specialize in retrofit applications of fiberglass insulation in Colorado’s existing housing stock. We know how effective fiberglass is as an insulator, as well as the issues that can require retrofitting (or, in rare cases, replacement).

If you have concerns about your home insulation, call REenergizeCO in Denver at (303) 227-1000 or in Fort Collins at (970) 323-3191 today. Our professional insulation installers serve homeowners throughout the Front Range.

Lifespan of Fiberglass Insulation

Fiberglass insulation was first introduced in the 1930s. In ideal conditions, you can still find some homes constructed in the 1940s–1950s with the insulation intact.

The question is whether the insulation is still providing an effective thermal barrier years after the fact. Optimally, fiberglass insulation can last 80–100 years before needing replacement; however, its useful life is reduced when conditions are unfavorable.

Some of the issues that can reduce the lifespan of fiberglass insulation in your home include:

  • Moisture — water damage is the number-one enemy of blown-in insulation or fiberglass batts 
  • Formation of mold and mildew
  • Insect, rodent, and other pest activity
  • Wind washing
  • Accumulation of dust, dirt, etc.

Fiberglass insulation does degrade over time, and conditions like these can accelerate the process. Most people become aware of these problems because they feel a draft or chill; notice a damp, musty smell; experience bad allergies; or see their energy bills go up.

Thankfully, insulation removal is not always necessary. In fact, we have found that removal is the exception and not the rule. As long as the insulation is not damaged by moisture, pests, etc., it is often possible to retrofit existing fiberglass insulation with new materials.

Read More: Is It Worth Removing Fiberglass Insulation?

Does Fiberglass Insulation Go Bad?

The fiberglass used in batts, rolls, and blown-in insulation is an inert material. As such, it doesn’t break down or “go bad” on its own.

However, this does not mean the material is indestructible. External factors such as moisture accumulation and animal activity can compromise the integrity of the insulation (see above). Prolonged exposure to water creates the ideal conditions for mold and mildew to grow. Infestations can result in droppings and debris being left in the insulation.

Problems like these don’t just reduce the efficacy of the insulation. They are also health hazards that can impact the comfort and air quality of your home.

Does Fiberglass Insulation Deteriorate Over Time?

Fiberglass insulation that is kept dry and free from pests can remain effective for decades or even a century. But, as the old saying goes, “nothing lasts forever.”

Even the most well-sealed home will generate dust and debris in the walls, floor joists, etc. These materials get in the spaces between fiberglass particles and weaken the thermal barrier created by the insulation. Loose-fill insulation of all types—fiberglass, cellulose, and mineral wool—is vulnerable to this “wear and tear.”

Deterioration due to dirt, dust, and other particles is very gradual. You could spend a lifetime in a well-insulated home and notice hardly any changes. However, deterioration of fiberglass batts, rolls, or loose-fill materials is accelerated if the insulation gets wet or damaged.

How Settling Affects Home Insulation

There is also the issue of fiberglass insulation settling over time. Insulation R-value is maximized when the material is tightly packed together. Settling occurs when the force of gravity causes insulation to slip down in a treated space, leaving gaps through which air can flow.

Settling is a gradual process. If the insulation was installed correctly (especially if a professional did the job), there should be minimal settling with little to no impact on your home efficiency or the environment inside your house.

If you do notice a change and it is determined that your home insulation has settled, the good news is that removal and replacement of the insulation is rarely necessary. Fiberglass insulation lends itself very well to retrofitting. Provided the original material insulation is intact and in good condition, a previously insulated space can be retrofitted with new blown-in insulation.

Talk to an Experienced Insulation Contractor Today

Fiberglass insulation remains an effective and affordable option for insulating houses. It is especially useful in attics, as well as strategic installations in other areas of the home.

At REenergizeCO, we recognize the value provided by fiberglass insulation. While many insulation companies push customers to opt for removal and replacement with new insulation, we take a more conservative approach that emphasizes retrofitting existing insulation.

Good-condition fiberglass insulation can enjoy renewed life with expertly installed blown-in insulation. This approach is much faster and less messy than a new installation. It is also easier on your bank account.

Contact REenergizeCO today to learn more about upgrading your home insulation. Our team performs fiberglass insulation retrofitting and new installations in Denver, Fort Collins, and throughout the Colorado Front Range.