Blown in insulation generally lasts for about 20 years. It's important to note, however, that the quality of the installation job will have a major impact on how long the insulation lasts. If you're not confident in your ability to do the job yourself, it might be worth hiring a professional.

It can last up to 20 years. Blown-in insulation is made of fiberglass, and it works by trapping air in small pockets. This insulation is then sprayed or blown into the wall cavities, and it forms a thermal barrier that helps to keep your home warm in the winter and cool in the summer. Blown-in insulation is a great option for homeowners because it's affordable, easy to install, and it lasts for up to 20 years. It's also effective at blocking out noise from outside, so it can help improve the sound quality of your home.