blown-in-insulation saint louis, missouri

Can You Add New Insulation Layers Over Old Ones?

St Louis - St Charles Insulation Company.

blown-in insulation attic-st-charles-mo
blown-in insulation attic St Charles, Missouri

Adding New Insulation Over Your Existing Insulation


Remove Old Insulation or Add New Insulation Over the Old Insulation

Whether your energy bills have been sky high and you want to make more eco-friendly choices or you’re renovating your home and figure now’s a good time to add new insulation, you may wonder: can I simply add new insulation over the old layers, or should insulation removal take place beforehand?

Great question. The answer is yes, you can put new insulation over old. But there are some circumstances that would require insulation removal first, such as in the case of contaminated insulation from pests, water or smoke. Moisture is the biggest culprit, as it can lead to mold and mildew, as well as ceiling and roof rafter rot.

Considerations When Adding New Layers Over Old

While insulation contractors in St. Louis MO will take care of all the insulation removal and installation, here are some things to know about the process.

  • “Faced” insulation shouldn’t be installed over existing insulation. This is when a material such as plastic or Kraft paper is attached to fiberglass insulation in an effort to control drafts, mold or moisture. That’s because the vapor retarder can trap moisture and lead to even more problems.
  • Batt or rolled insulation or blown loose-fill insulation types are good candidates to be installed over old insulation.
  • Rolled insulation should not be fixed in place with tacks, as the R-value can be compromised when the material is flattened.
  • Contractors should seal for air leaks before installation of new insulation, as leaks can compromise energy efficiency.

Should You Remove Old Insulation?

As we said before, there are some circumstances where you should remove insulation first before adding more. This will entail an evaluation of your home’s existing insulation prior to making a decision.
You should not add new over old if:

  • Your old insulation is soggy with water. Whether this has happened due to a hidden plumbing or roof leak, mold growth and structural damage due to rot or insect infestation can occur.
  • The old insulation is made of vermiculite material: Because this insulation can have asbestos in it, it has to be removed by professionals to avoid health complications.

Tips When Adding New Insulation

  • Don’t install insulation with vapor barriers, which can cause condensation.
  • Install roll or batt insulation perpendicular to joists.
  • Loose-fill insulation can be installed on top of old insulation.
  • Whole-house air sealing is a wise idea before adding new insulation, as leaks will reduce energy efficiency and comfort.

Addict Insulation will take care of all these details so you don’t have to worry about a thing. We will evaluate your old insulation and let you know if removal is necessary first. We will also evaluate your home size and other factors to determine the best kind of new insulation that should be used.

Call Addict Insulation In Missouri

To book your consultation on removing old insulation and adding new layers, contact us in St. Charles MO or St. Louis MO at 636-233-7314.

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