Get matched with top doorbell installation pros in Clayton, CA

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.

Yes, basement insulation needs a vapor barrier due to its susceptibility to moisture seeping in from the outside of the house. You should install a moisture barrier before you install insulation or purchase insulation that comes prebuilt with a moisture barrier to avoid water damage in your insulation and costly mold and water remediation expenses. 

Adding insulation to ceilings is an excellent way to increase the energy efficiency of your home. If your home's layout is such that you need insulation in the ceilings rather than in the roof, it's likely that at least some insulation already exists in the space. However, each additional inch of insulation you can add boosts the R-value by between 2.2 and 4.2.

Rigid foam board insulation is one of the safest insulation materials for basement walls. The panels offer a moisture barrier to prevent mold and mildew build-up. At the same time, this material is also fire-resistant, so you don’t have to worry as much about a fire breaking out as you would with spray foam insulation.