Get matched with top doorbell installation pros in Vienna, MO

You do not always need to remove old insulation before adding new. If the existing insulation is in good condition—not wet, physically damaged, moldy, or infested with pests—you can add new insulation directly on top of it for a compounding effect. You can also mix different types, such as adding blown-in insulation around existing fiberglass batts.

However, removal is recommended if the old insulation is compromised by water damage or pests. You should also remove it if you plan to install a different type of insulation, like switching from roll or batt insulation to spray foam. If the existing insulation is very old or damaged, you will likely get more benefit from removing it and starting fresh.

The time required for insulation installation can range from a few hours to a few days, with most projects taking 1-3 days to complete. The final duration depends on the project's size and complexity, the area size, and the type of insulation being installed.

Blown-in insulation works, but only for unfinished attics. Also, it isn’t the longest-lasting nor the most effective option. For better options, look into spray foam insulation or natural fiber batts. They typically have a longer lifespan, better heat resistance, and stronger sound-proof abilities. Spray foam insulation costs about $1.25 to $1.50 per square foot, but can go up to more than $4 per square foot. Fiber batt pricing varies depending on the material.

The best type of attic insulation depends on where you live, your budget, and what stage of construction the attic is in. For example, if you're building a house, then structural insulated panels are a worthy investment since they're easy to install during construction and they're the most energy-efficient type of insulation.  

Additionally, if you live in a very warm climate, then you can potentially save quite a bit of money by opting for reflective insulation, which is more affordable than comprehensive insulation but doesn't work well for cool climates. Blown-in, loose-fill, and spray foam insulation are all great options for attics in moderate climates.