If there is no water damage or signs of insect or rodent infestation, it may be because the attic insulation is not being removed. The bottom line is that old insulation must be taken out because it impedes air flow to the attic, can promote mold growth and is dirty. The old floor insulation has been exposed to outside air due to the attic having ventilation. There is no real way to separate these unpleasant substances from insulation, so it's best to completely eliminate them.
Before installing any new insulation, disinfect and sanitize the area for greater peace of mind. If your current attic insulation is infested with mold, taking it out will save you a lot of stress. Insulation becomes less effective and mold could damage other components of the attic. In addition, it is not advisable to place other insulating material on top of the mold-infested insulation.
We know that the old traditional attic floor insulation must be removed before spraying the roof covering with foam, as this makes it difficult for air to flow into the house. According to the International Association of Certified Home Inspectors, the typical lifespan of attic insulation indicates that spray foam insulation, home wrapping insulation, and duct tape can last up to 80 years or more. The big problem is that this creates the perfect conditions for mold to grow not only in the insulation, but also on the roof and other areas of the attic. If there is an insulating layer of fiberglass or cellulose on the attic floor, as the air in the living room heats up and rises, you'll want to move to the attic. But if you're thinking about improving insulation, you might be starting to wonder if you'll have to remove the old attic insulation to install the new materials.
Many homeowners have questions, for example, whether attic insulation helps or not and how much attic insulation is needed to save energy. If the old insulation is misaligned, removing it might be easier, or it could be realigned to obtain the insulating properties. Another reason you'll want to remove the insulation from the attic floor is that if airflow becomes difficult, there will be a temperature difference between the attic and the rest of the house. That old insulation could cause more problems than it's worth and hinder the ability of spray foam to effectively insulate the attic.
When you insulate the attic floor with spray foam, you basically isolate it from the rest of the house, creating an airtight seal. The last thing to keep in mind is that any old insulation must be removed from the attic floor before the spray foam can be applied. Here are some scenarios where you should completely remove and discard old insulation before adding any new insulation material. If you're hiring a local spray foam insulation contractor, you must remove any pre-existing insulation before proceeding with the project.
Although attic insulation is said to last between 80 and 100 years, it loses effectiveness as it ages. This is due to one of the main reasons why you want to remove the old insulation from the attic floor when insulating the roof covering with spray foam. When cellulose, fiberglass, or other insulating materials in the attic fall, “empty spaces” are created where mold can grow, become dirty and lose effectiveness.
