Blown-in insulation generally lasts 15 to 30 years. Its actual lifespan heavily depends on the material, environmental factors like moisture, and whether it has been compressed or damaged by pests.
As a general rule, insulation should be replaced or retrofitted every 15 to 20 years. However, it may need replacing or retrofitting sooner depending on the type of insulation installed, the R rating of the original insulation, compression and movement over time, and whether any damage has occurred.
Blown-in insulation, when installed correctly, can last between 15 to 20 years, sometimes even up to 25 years. However, like all insulation types, it will settle over time. This settling is a natural process that affects both fiberglass and cellulose varieties.
Moisture Issues and Risk of Mold Growth – Because blown-in cellulose is made of paper products, it soaks up any and all moisture in the insulated area. A roof leak, pipe leak or high humidity can cause water to infiltrate the insulation, and insulated areas take a long time to dry back out.
Blown-in insulation, available in fiberglass and cellulose varieties, generally lasts 20 to 30 years. Fiberglass tends to be the more durable option, while cellulose is more sensitive to humidity, which can affect its longevity in certain climates.
Mice are curious and always searching for safe, snug, and warm nesting sites. Attics filled with blown-in insulation provide an excellent option–from the mice's point of view. As long as there is a ready food source. Mice are omnivorous and will eat and chew on almost anything including wood and electrical wires.
The best non-toxic insulation is either mineral wool or foam insulation inserts.
Types of Blown-In Attic Insulation
It's one of the oldest types of insulation still widely used, with a history going back to a time when settlers would stuff the walls of their homes with old newspapers and similar materials to help keep out drafts.
Key Takeaway: Spray foam insulation offers greater energy savings and air sealing benefits, especially in extreme climates, while blown-in insulation is a more budget-friendly option with moderate savings.
Limited Energy Savings
Compared to insulating exterior walls or attics, insulating interior walls often provides less significant energy savings. The impact on your overall home energy efficiency may be minimal, especially if your home already has good exterior insulation and an efficient HVAC system.
Technically, mold does not typically grow on the insulation itself. Fiberglass is not a viable food source for mold. Yet mold growth is often found on the top surface of attic insulation.
When fiberglass fragments are inhaled and deposited in the small air sacs of the lung, the alveoli do not close up and trap the particles. The particles are expelled from the alveoli and there is a rapid clearance of fiberglass dust particles from the lungs.
Whether or not you need to remove the existing insulation depends on its condition. Removing old insulation is generally recommended if it's damaged, contaminated with mold, or infested with pests.
Insulation levels are specified by R-Value. R-Value is a measure of insulation's ability to resist heat flow. The higher the R-Value, the better the thermal performance of the insulation. The recommended level for most attics is to insulate to R-38 or about 10 to 14 inches, depending on insulation type.
Look for the following common signs:
Let's get this straight: As temperatures get colder, loose fill fiberglass attic insulation loses R Value, while cellulose attic insulation actually increases R Value!
By insulating your solid walls, you could save energy, lower your heating bill and make your home more comfortable. If your house was built in the 1990s or after, it'll likely to already have wall insulation to keep the heat in.
What time of year is Insulation cheapest?
Foam insulation is a common target because it's easy for them to chew through. The material offers little resistance, allowing mice to create tunnels or nests within the insulation. But mice aren't just interested in chewing for the sake of it—they're also drawn to the warmth and shelter insulation provides.
Potential problems with spray foam insulation
reduce air circulation and ventilation within a roof space. lead to dampness and condensation on the underside of a roof because it forms an air barrier and stops moisture from escaping. place timber-framed roofs at risk of decay.
5 DIY Ways to Insulate Your Home on the Cheap
Superior Thermal Performance: Cellulose insulation has a higher R-value per inch than fiberglass, providing better thermal resistance. Sound Insulation: Cellulose also provides excellent sound insulation due to its density, making your home quieter.
Insects, squirrels, mice and raccoons dislike cellulose insulation because it contains boric acid which is both a flame retardant and a rodent repellent.
Air movement — insulation doesn't stop air from flowing through gaps, cracks, and penetrations. Moisture — wet insulation loses a significant portion of its rated performance. Radiant heat loss — your body and your walls are constantly exchanging heat regardless of what's in the stud cavity.
The improved blown-in insulation was used by many homes during the 1970s. Polyurethane spray foam insulation was considered a great advancement. Though it was developed by the military in the 1940s, it didn't become popular in homes until the late 1970s and early 1980s.