While many types of insulations aren't likely to grow mold, there are some that do and when they do it should be taken care of as soon as you realize that it is a problem. In most cases blown in forms of insulation will not get moldy, however fiberglass insulation and rockwool insulation that has been laid in a wall cavity, in the ceiling, or in the attic may get wet and or moldy. In both situations it is important to take action as soon as possible.

Dress For Safety.
Before you attack any mold problem you need to dress for safety. This means that you will need to wear rubber gloves and never touch mold without them on. You should also wear safety goggles to protect your eyes from the spores and a respirator designed for protecting you against mold spores. For more on what you should be wearing to protect yourself see the article What To Wear When Removing Mold From Your Home.

Contain The Area.
If there isn't a very large area of mold then a containment field isn't necessary to contain the area. However, a small mold mess is described as being less then ten square feet and many issues with mold in the insulation are larger than that. It is a good idea to set up a containment field if the mess is large, if you don't know how big it is, or if any of your family members are already experiencing health problems related to mold. Mold can be dangerous and you want to keep it from spreading around the house. See The Health Concerns of Mold for more information.

To set up your containment area you will need 2-3 millimeter thick plastic sheets or drop clothes. You will need to tape them over the doorways and any open walls. If the room is large and the mold isn't all over you should make your containment area smaller. Attach your plastic sheeting to the ceiling with duct tape and to the floor with duct tape or tacks. Make a doorway by overlapping the plastic sheets and taping them to the ceiling, but not the floor. Put a fan in the window to blow the spores out and to keep the pressure in the room less then the pressure outside the room. For more on setting up a containment area check out the article Mold Removal: The Containment Area.

The Process.
To clean this mess up you will have to make sure that you go slowly and carefully. The more you move things around the worse.

  1. If need be remove the wallboard to get to the insulation. If the wallboard is moldy (and it likely will be) then you should get rid of it by cutting it into small squares and throwing it away in a thick black garbage bag. Seal it with duck tape and place it in a second garbage bag (also sealing this one). For more information on dealing with the wallboard see the article Mold Removal: Dealing With Wallboard. For more information on disposing of moldy items see the article How To Dispose of Moldy Items.
  2. Pull out the insulation mats or boards. If they are wet or moldy they need to be disposed of using two layers of trash bags or two layers of heavy duty plastic. In both cases you should duct tape them to seal them. If possible possible you should pass the wrapped insulation through a window rather than take it through the house. This will release fewer mold spores into your house.
  3. If there is mold inside the wall cavity, ceiling, or floor then you will need to remove that. To do this you should spray it down with hydrogen peroxide until it is all damp. Let it sit for ten minutes. Come back and scrub the mold up with a sponge or scrub brush. Make sure you are removing as much mold as you can.
  4. Even if you don't see any mold in the cavity you should spray it down with hydrogen peroxide (or another cleanser, see Mold Killing Cleansers for more options) and let it sit there until it is thoroughly dry. If the cavity is damp then you can use fans, heaters, and dehumidifiers after you have cleaned up all the spores to speed up the drying time.
  5. Now you should put fresh insulation in and then fresh wallboard. It is a good idea to use materials that resist mold if the mold issue is caused from general moisture in the home. Consider having a cellulose insulation sprayed into the wall cavity to prevent mold. Use wallboard that is resistant to moisture and molds and finish with mold resistant primer, paints, and or wallpaper.

Mold Prevention.
It is never enough to just get rid of the mold. You need to make sure that whatever caused the mold in the first place is taken care of. There are a number of different reasons that you may have mold problems in your walls and insulation. Make sure that you are taking care of those problems at the same time as getting rid of the mold.

  • Water leaks often cause this kind of damage.
  • When the roof leaks it too can cause this same type of issues.
  • Floods are unavoidable and they aren't really something that you need to fix, but knowing that is the cause for your mold issues is important.
  • Finally, there are times when the moisture builds up. This is caused from too much humidity, too much water in the area, and also a house that is sealed too well. If this is your problem you will need to make sure that you are lowering your humidity.

To prevent your mold you should see the article How to Prevent Mold In Your House.

It is important to get rid of mold as soon as possible. When mold has begun to grow in your walls and is using your insulation as a good place to find food (they actually eat the dust and dirt in the insulation rather than the insulation itself) then you will want to make sure that you pull your wallboard off, dispose of your insulation, clean everything, and put it all back together again.