Adding New Insulation Over Old Layers

Do you need more insulation in your home? If it was built in the 1970s or earlier, chances are it does! Older homes often don’t meet today’s energy efficiency standards and are under-insulated. Think it may be time to re-insulate? Can you put new insulation on top of old insulation? This is a question we get a lot.

In short, yes—you can install new insulation over old insulation. Keep reading to learn more!

Can I Add New Insulation Over Existing Layers?

According to ENERGY STAR®, you can put new insulation over old insulation, “unless it is wet. If it is wet or appears that the insulation has previously been wet, you should look for the cause and repair the problem…” Wet insulation is problematic, as it can lead to mold, mildew and sometimes the rotting of ceilings or roof rafters.

Although insulation professionals will handle the installation for you, here are some things to keep in mind about removing old insulation and installing new insulation over old insulation, according to ENERGY STAR:

  • “Faced” insulation should not be placed on top of existing insulation in the attic. Any new batt or roll insulation installed over existing insulation in the attic needs to be without a vapor retarder (face). The vapor retarder on top of or between layers of insulation can trap moisture. Any existing batt or roll insulation in the attic should have the facing against the attic drywall floor or no facing at all.
  • Batt or rolled insulation or blown loose-fill insulation (fiberglass or cellulose) can be installed on top of old insulation.
  • Insulation should be rolled out perpendicular to the joists—and unfaced rolls should be used.
  • Rolled insulation should not be tacked down. The R-value can be reduced if the insulation is squashed or flattened.
  • Any vermiculite insulation found in your attic should be tested. If the test reveals that asbestos is present, the vermiculite should be removed by a certified professional before installing more insulation.
  • It’s recommended to air seal before installing insulation since air leaks can hinder the performance of insulation and significantly reduce the energy efficiency and comfort of your home.

The most important thing to keep in mind is that you don’t have to worry about all this. Professionals will be able to answer any questions you have—and handle your entire home insulation project.

If you live in the Indianapolis area, the team at Overhead Door Co. of Indianapolis & Muncie can help. We have experience installing all types of insulation. Contact us today to learn more about our services or if you’re ready for a quote!