Q & A
What is mold?
There are thousands of mold species. Chances are good that you’ve seen some, growing on a loaf of bread or a piece of over-ripe fruit. Or, perhaps you’ve seen it on the woodpile in the backyard. Mold is a fungus that is present just about everywhere-even in the air, both indoors and out. There are thousands of mold species. Chances are good that you’ve seen some, growing on a loaf of bread or a piece of over-ripe fruit. Or, perhaps you’ve seen it on the woodpile in the backyard. Mold is a fungus that is present just about everywhere-even in the air, both indoors and out.
Household mold is caused by excessive moisture in the home. Here are some common causes of moisture and mold growth:
- leaky plumbing
- flooding (due to natural disaster or plumbing)
- malfunctioning air-conditioning and/or heating units
- improper or absent venting in bathrooms, laundry rooms, and kitchens
- leaky roofs
- ill-fitting or old, leaky windows
You can usually see mold. It often looks like black, gray, or green spots — though it can be a variety of colors, depending on the species. You may be able to smell it too. Most molds have a distinct, musty smell.
It is possible to have mold and not know it.
This is particularly true when mold results from a plumbing leak inside a wall or other hidden area. Peeling paint, bulging wallboards, and/or discolored wallpaper may indicate the presence of mold. If you suspect hidden mold, hire an experienced professional to perform an inspection.
If the mold is confined to an area no larger than 3′ x 3′, you can probably handle the job yourself.
If the mold covers a larger area, or is a result of extensive water damage or sewer water, you’ll need professional help. It’s important to hire someone with experience and someone who has the right tools to keep the mold contained.
Plan on requesting quotes from at least three contractors. If your state contractor licensing board regulates mold remediation, find out if your potential contractors have a mold remediation license.
Taking care of mold is a two-step process. You must first repair the cause of the moisture that is encouraging the mold growth. Then, you must remove the mold itself.
A small mold problem may be inexpensive, perhaps the cost of repairing a leaking pipe and buying some basic cleaning and safety supplies. Larger problems, such as remediating mold caused by a flood, can cost thousands of dollars.
In general, experts agree that some people experience nasal problems, respiratory problems, and eye or skin irritations due to mold. People who are sensitive to mold often have more severe reactions.
From a scientific perspective, there is still a lot to learn about molds and their effect on human health, so it’s best to error on the side of caution. The Center for Disease Control (CDC) suggests this rule of thumb: If you see or smell mold, remove it. It may pose a health risk.
If you suspect that mold is causing a health problem, contact your doctor. You can also refer to the Environmental Protection Agency’s Mold Resource page for more about mold and health.
You can buy a humidity monitor at home improvement stores or online. Basic models sell for around $10. The humidity in your home should be kept between 30-60%.
There are no standards for acceptable or unacceptable levels of mold. So, a test is of little value, unless you want to take a surface sample to ensure that mold has not returned to a remediated area. Even in cases of remediation, though, if the underlying moisture problem has been fixed, the mold will probably not flourish.
If you can see the mold, you already know you have it in your home. In most cases, it’s best to spend your time and money repairing the moisture problem and removing the mold, not paying for mold testing.
If you are removing mold from a small area, household cleaning products will probably work just fine. In fact, the Environmental Protection Agency (EPA) recommends using detergent and water on solid surfaces. Depending on the surface, you can wipe it clean, or use a scrubbing brush.
Bleach is often recommended for killing mold. But, the EPA cautions that it is not enough to kill the mold, since dead mold can still be an allergen.
The mold must be removed. If you are determined to use bleach, be sure to use it in a well-ventilated area (windows and doors open). And, don’t mix it with other cleaning products. Mixing products can cause toxic vapors. For more safety tips, see the EPA’s Mold Cleanup Guidelines.
No. Remove the mold and dry the area completely before painting or caulking. Painting or caulking over existing mold will not kill it.
Yes. Moisture can get trapped inside new homes that are air-tight, especially if kitchen and bathroom ventilation is inadequate or absent. Also, if your carpet was laid directly on a concrete slab without a vapor barrier in between, your carpet may absorb moisture and be subject to mold growth as well.
If you repair the moisture problem and have the area dried out within 24-48 hours, mold will probably not grow. It’s a good idea to recheck the area periodically for signs of mold growth.
If you have carpets or upholstered items that do not dry within 24-48 hours of getting wet, you should remove them from your home and replace them.
Yes. The Environmental Protection Agency (EPA) recommends an N-95 respirator, which you can purchase at home improvements stores. For more information on the N-95 respirator and other safety guidelines, see the EPA’s Mold Cleanup Guidelines.
Prices range from $295 and up, depending on the location and size of the home, and how many samples are taken for analysis.
The seller usually pays for the inspection, but there is no set custom.
Most homeowner’s insurance do not cover mold, especially if the mold results from a maintenance issue, like poor ventilation, leaky plumbing, clogged rain gutters, or a malfunctioning air-conditioner.
Mold may be covered if you can establish that it resulted from a covered peril, such as rain that entered the home. Be aware, though, that some policies have an absolute mold exclusion.
If the mold has been removed and the moisture problem has been fixed, the mold will probably not flourish again. Remember that mold needs moisture in order to survive. If the area is visible, you can check it from time to time to ensure that mold has not returned.
Disclosure rules vary by state. But, it’s in your best interest to disclose any mold issues. If you paid for professional mold remediation, you can show buyers a copy of the service contract.
A pre-inspection by a qualified home inspector will also help assure potential buyers that the problem has been resolved.