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What Happens if Cellulose Insulation Gets Wet?

Cellulose loose-fill insulation being blown into an unfinished wall.

One of the most popular types of insulation for older homes is cellulose insulation because it’s relatively easy to add to an existing structure with minimal remodeling. But what happens if it gets wet?

With roofs that are often several decades old, roof leaks can be quite common in older homes, and they can cause significant harm to any cellulose insulation that’s installed.

How To Tell if Your Insulation Is Made of Cellulose

Cellulose insulation is a loose-fill product made primarily from recycled newspaper that has been treated to resist damage from fire, mold and pests.

It’s usually blown into place using professional equipment, and it’s usually an off-white, tan or gray color, with a texture similar to fluffy down feathers or paper pulp. You’ll find cellulose insulation most often in finished walls, ceilings and floors, as well as in the attic.

What Happens to Wet Cellulose Insulation?

When cellulose insulation gets wet, it tends to settle, compacting down into a tighter space within the ceiling, floor or wall cavity. This leaves part of the cavity devoid of insulation, and in the areas that do have insulation, the material is now so dense that it loses a lot of its effectiveness.

Insulation depends on trapping pockets of air to prevent heat conduction through the material, so when insulation is compacted, those air pockets are lost and it can’t do its job as well.

In addition to losing effectiveness, wet cellulose can also encourage the growth of mold and mildew, contaminate your indoor air with mold spores and lead to structural problems as wood framing begins to rot.

Although cellulose insulation itself is resistant to mold, when it’s soaked with water, it can keep surfaces adjacent to it saturated with moisture, creating the perfect environment for mold and wood rot.

What To Do With Wet Insulation

If a roof leak or a plumbing problem has damaged your cellulose insulation, it’s important to act quickly to keep the damage to a minimum. Here are a few things you can do to save as much of the insulation as possible:

  • Stop the leak: Whether you need to shut off the main water supply or have the roof repaired, it’s essential to stop the leak at its source.
  • Remove the wet insulation: Discard any insulation that has been completely soaked with water so the rest of the space can dry quicker.
  • Dry the area: Use a fan to remove any remaining moisture as quickly as possible.
  • Clean the space: Clean the area and sanitize it to prevent the growth of mold.
  • Monitor the remaining insulation: Keep an eye on the remaining insulation after all damaged material has been removed for signs of mold, settling or other damage. Have a professional inspection done to make sure the insulation is safe and effective.
  • Replace the insulation: If a large portion of your cellulose insulation was affected, or a professional inspection has found that the insulation is too damaged to be salvaged, it’s best to remove and replace it.

Trust OJ Insulation for Insulation Replacement in California

When you need an experienced team to remove and replace the insulation in your California home, talk to our team at OJ Insulation. We offer insulation replacements and new installations throughout southern California and the Bay Area.

With over 40 years of service and the best products on the market, you can count on us for the highest levels of quality, energy efficiency and comfort.

Call us today at (800) 707-9278 to request your free insulation replacement quote in southern California or the Bay Area.

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