Fiberglass insulation is constructed of tiny shards of glass that form pockets to trap air and help restrict the transfer of heat. Its naturally mold resistant in that the material itself is not a food source for mold.
Wet Insulation Can Lose Its Insulating Value
When your insulation becomes wet, it will start to lose some functionality, such as inhibiting heat transfer. Damp insulation can lose about 40 percent of its insulating R-value. You might think fiberglass is waterproof, but the thick batt can retain moisture.
Technically, mold does not typically grow on the insulation itself. Fiberglass is not a viable food source for mold. Yet mold growth is often found on the top surface of attic insulation.
As mentioned, loose fill insulation like fiberglass becomes discolored when it filters the air leaking from your house. While it might not be immediately noticeable, over time the air leaking from your house carries dust, other particles and moisture, which is what ultimately turns the fiberglass insulation black.
Mold can grow on the fiberglass insulation backing, which is made of paper and is a mold food source. Fiberglass insulation without backing may be the best choice. Cellulose insulation is constructed of ground paper, which is an ideal food source for the growth of mold if it becomes wet.
Fiberglass insulation, a man-made mineral fiber constructed from a variety of materials, such as sand and recycled glass, is the most popular form of insulation in the United States -- more than 90 percent of homes in America are lined with the pink stuff [source: Spencer and Gulick].
Therefore, when looking for and trying to identify asbestos insulation, check the areas that are the most vulnerable to heat transfer. That's where you'll find insulation material, which may contain asbestos. Asbestos insulation is usually found in the less-visible parts of the home, including the following: Attics.
Unless damaged, it can last 80 to 100 years in most houses before it needs to be replaced. However, insulation can start falling from fiberglass batts after 15 to 20 years, so if your insulation was installed in batts well over a decade ago, it might be time for an inspection or a home energy audit.
Douse the insulation in a bleach solution (1 cup bleach and 1 gallon hot water) and scrape clean with a wire brush.
When portions of insulating material harbor mold spores, then you should replace it. Even if the material dries out, mold spores can become airborne and travel to other wet areas of the house. If you catch it early enough, then you'll only need to replace a small section of material, keeping your cost lower.
How long does it take for mold to grow on wet insulation? Mold begins growing between 24-48 hours after your insulation gets wet.
There are a few ways that insulation in the home can have an adverse health effect. Insulation can make you ill in a variety of ways, often presenting some allergies or the flu. Improper Installation--This could be poorly installed or hung insulation, or simply using the wrong material in the wrong space.
If the insulation became wet from water that contained any contaminates such as flood water and sewage, then the affected insulation and the wallboard are likely ruined, and both materials need to be removed as soon as possible.
Cleaning Up: when fiberglass insulation gets wet, it won't just immediately soak up the water. Fiberglass doesn't absorb water, so no instant damage will be done to your home's structure. However, if the problem goes unfixed, that will do damage and seriously decrease the insulation's functionality.
You can absolutely new insulation over old insulation… as long as it isn't wet. Energy Star advises as follows: “If it… appears that the insulation [is wet or] has previously been wet, you should look for the cause and repair the problem to prevent a reoccurrence. Remove any wet insulation.
Your insulation needs to be removed along with the droppings, as it'll carry some of its toxicity if left in your attic. Removing old insulation and replacing it with new ones will not only rid your home from any rodent infestation and mold, but also improve its energy efficiency and overall air quality.
Pink Batts insulation will last up to 50 years before it needs any attention. Fire and rot resistant, Pink Batts will not degrade like many insulation materials, and is not a good food source for vermin, the scourge of many cavity insulations.
There have been many tests on the health side effects of fiberglass by government agencies and private labs, with the only generally agreed upon fact being that fiberglass is an irritant, which becomes immediately apparent when handling the pink insulation common in houses.
The pink coloring dates back to the invention of modern fiberglass insulation by an employee of the Owens-Corning company in 1938. Owens-Corning colored its insulation in a distinctive way for marketing purposes at first, and pink insulation became so well-known that most fiberglass insulation is now made to be pink.
If you breathe asbestos fibers, you may increase the risk of several serious diseases, including asbestosis, mesothelioma and lung cancer. Asbestos exposure may increase your risk for cancers of the digestive system, including colon cancer.
Improperly Installed Attic Insulation Can Make You Sick
They have a sickening odor which can make people ill after long exposure. If your attic insulation was not installed properly, it is important to rectify the problem immediately to avoid serious health problems.
Blown-in cellulose insulation is fire retardant
This is because it is treated with borax, boric acid, and/or ammonium sulfate (all of which are considered non-toxic in this application).
Two common toxins found in attic insulation are formaldehyde and asbestos. These types of toxins are now banned from being used, but many older homes still have this type of insulation in them. If you have an older home with old insulation, you may have these toxins still in your home.
Blown fiberglass comes in three common colors: white, pink or yellow and the colors simply identify the manufacturer. Blown-in fiberglass insulation in attics typically has an R-value of 2.5 per inch. The density of the blown-in fiberglass determines the R-value just like it does for a batt.