The thermal barrier of a home should consist of a continuous layer of insulation on all sides—including the lowest floor, the exterior walls, and the ceiling or roof. Doubling the thickness of insulation will double the insulation's R-value, cutting heat loss in half.
How Much Insulation is Too Much? In Southern California, you'll want to shoot for an R-Value of around 30 for an optimum experience. The California Department of Energy's 2019 Building Envelope requirements state the minimum R-Value for wood-construction ventilated attic spaces in California is R-22.
Direct contact with fiberglass or breathing airborne dust containing fiberglass may irritate the skin, eyes, nose, and throat. The symptoms of irritation are often nonspecific, temporary, and may include itching, coughing, or wheezing.
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.
Exposure to VOCs can cause irritation of the eyes and respiratory tract, headaches, dizziness, and other side-effects. These can impact more on people with sensitive respiratory systems, such as people with asthma and certain allergies.
Improperly installed insulation can have a negative effect on a home with regards to mold growth. For example, gaps left in the insulation can create cold spots that can lead to condensation and surface mold growth.
Symptoms of Inhaling Fiberglass Insulation
When inhaled, fiberglass particles cause irritation of the throat, mouth, and nasal passages, causing you to cough. Nose bleeds can also occur. Regular exposure can cause asthma. Because this is usually occupational, it's typically referred to as construction workers asthma.
Measures can be taken to reduce exposure after a person has come in contact with fiberglass. Eyes should be flushed with water and any area of exposed skin should be washed with soap and warm water to remove fibers.
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.
It is possible to over-insulate your house so much that it can't breathe. The whole point of home insulation is to tightly seal your home's interior. But if it becomes too tightly sealed with too many layers of insulation, moisture can get trapped inside those layers. That's when mold starts to grow.
Unless your home was specially constructed for energy efficiency, you can probably reduce your energy bills by adding more insulation. Many older homes have less insulation than homes built today, but even adding insulation to a newer home can pay for itself within a few years.
It's possible to over-insulate an attic as too much will cause moisture buildup and eventually result in mold. Eventually, adding more insulation leads to diminishing returns in trapping heat as well.
Yes! 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.
DIY Frequently Asked Questions / Can I stack insulation to get a higher R-value? Yes. For example, two R-19 batts can be stacked on each other to create R-38 insulation. You also can add loose-fill insulation on top of a bottom layer of batts.
Batt or rolled insulation or blown loose-fill insulation (fiberglass or cellulose) can be installed on top of old insulation.
"Fiberglass insulation should never be left exposed in an occupied area, according to the American Lung Association," says ALA's Godfrey. "Exposed fiberglass insulation, once in the air, does cause respiratory reactions, such as dry, scratchy throat and coughing, as well as acting as a skin and eye irritant.
A Japanese medical researcher has reported the first evidence that fiberglass, which is produced by the billions of pounds annually here and widely used as an insulating material, may be responsible for causing lung disease in workers similar to diseases caused by asbestos.
The industry officials said fiberglass and most of the other synthetic fibers were different from asbestos in several important ways. For one thing they are thicker and do not penetrate the lung as deeply. And these fibers tend to be more soluble and tend to dissolve in human tissue before they cause tumors, they said.
As a result, people who handle or are exposed to this insulation can breathe in tiny bits of glass. After a while, those bits can get stuck in a person's lungs, leading to respiratory ailments. Fiberglass exposure can also inflame the eyes and skin, making them itchy.
Causes of Itchiness from Insulation
Coming into contact with fiberglass insulation material can cause itchiness on your skin. The tiny fibers of glass from the insulation wool can irritate your eyes and your skin. Too much contact with fiberglass can result in irritant contact dermatitis or skin inflammation.
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.
Black Spots on Insulation caused by Air Leakage
Particulates released by combustion appliances, such as wood stoves, boilers, furnaces, diesel heaters or auto exhaust, can produce very fine soot that can build up over time in insulation. Tobacco smoke can also contribute.
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.
Dust. You can clean your house all you want but if the attic is full of dust, you will still have health issues. Dust mites blown into the air cause severe colds, sneezing, watery eyes and asthma. The dust could be coming directly through openings on the roof or blown into the living space by your HVAC unit.