Should you remove your old attic insulation?

Going into hot, dusty attics is something we do every day, all year round. While crawling around all those attics we often get asked, “Does my insulation need to be removed?”. You might be thinking that the old stuff on the floor of the attic will add additional insulation up there, but that isn’t always the case. That old insulation could actually cause more problems than it’s worth. 

Old insulation with signs of pest infestation.


Attics are vented. Air leakage through gaps, cracks, and penetration in the attic floor deposits dirt and dust in batts. This is called wind washing. Wind washing reduces the effectiveness of attic insulation by pushing insulation away from the edges of the attic space. As the insulation protection decreases, you will also notice a diminishing comfort of your home in areas such as less noise control, inability to maintain proper indoor heating and cooling, along with the danger of circulating allergens. 

Pests Love Insulation

Mice, bats, birds, and squirrels will nest and urinate in fiberglass batts and make a mess. You may even hear them tapping around your attic at night. These critters will build nests and use the insulation as their home while seemingly multiplying and inviting all their friends to their new home. Pest urine and droppings are hazardous and need to be removed along with all the insulation in the infected areas.  In this situation, insulation removal is necessary.  We typically use cellulose blown in insulation because the fire retardant chemical borate is also a rodent deterrent. 

Water Damage

Insulation can hold moisture for a long time and become a source of mold spores or mildew. Wet insulation will join its fibers together and create clumps in your attic. If your insulation is compressed or contaminated, then it will lose effectiveness. Damp insulation can lose about 40 percent of its insulating R-value. 

It can be challenging and overwhelming to know what to do about your current attic insulation. That’s why we offer a straight-forward Home Energy Audit that will assess your home and help determine any necessary work. Contact Comfenergy today to get started. We’re happy to answer any questions about the process of making your home run efficiently and safely!