Mold Facts

Frequently asked questions
 

Note: Mold determination is not part of a general home inspection. If we identify any moisture related problems in our report, you should take it upon yourself to consider having the home tested for the presence of mold prior to the end of your contingency period.

Molds are simple, microscopic organisms whose purpose in the ecosystem is to break down dead materials. Molds can be found on plants, dry leaves, and on just about every other organic material. Some molds are useful, such as those used to make antibiotics and cheese. Some molds are known to be highly toxic when ingested, such as the types that invade grains and peanuts. Most of the mold found indoors comes from the outdoors.

Molds reproduce by very tiny particles called spores. The spores float in on the air currents and find a suitable spot to grow. Spores are very light and can travel on air currents. If mold spores land on a suitable surface, they will begin to grow.

Molds need three things to thrive- moisture, food and a surface to grow on. Molds can be seen throughout the house, and can be found in most bathrooms. Mold growth can often be seen in the form of discoloration, and can appear in many colors-white, orange, pink, blue, green, black or brown. When molds are present in large quantities (called colonies) they can cause health problems in some people.

Who does mold affect?

Mold spores can cause adverse reactions, much like pollen from plants. Mold spores cause health problems when they become airborne and are inhaled in large quantities. Everyone is exposed to mold in some concentration in the outdoor air. Indoor exposure to molds is not healthy for anyone. In particular, people with allergies, existing respiratory conditions or suppressed immune systems are especially susceptible to health problems from mold exposure. Additionally, infants and children, pregnant women and the elderly can be sensitive to the effects of mold exposure. Some molds are more hazardous than others. For some people, a small number of mold spores can cause health problems. For others, it may take many more.

What are Symptoms of mold exposure?

There are many symptoms of mold exposure. The extent of symptoms depends on the sensitivity of the exposed person. Allergic reactions are the most common and typically include: respiratory problems such as wheezing and difficulty breathing; nasal and sinus congestion; burning, watery, reddened eyes or blurry vision; sore throat; dry cough; nose and throat irritation; shortness of breath; and skin irritation.

Other less common effects are: nervous system problems (headaches, memory loss, moodiness); aches and pains; and fever. If you have any of these symptoms, and they are reduced or completely gone when you leave the suspect area, chances are you have been exposed to some sort of allergen, quite possibly mold.

How can I tell if I have mold in my home?

Some mold problems are obvious - you can see it growing. Others are not so obvious. If you can see mold, or if there is a musty odor in your home, you probably have a mold problem. Areas that are wet, or have been wet due to flooding, leaky plumbing, leaky roofing, or areas that are humid (such as bathrooms and laundry rooms) are most likely to have mold growth. Look for previous water damage.

Visible mold growth may be found underneath wallpaper and baseboards, behind walls, or may be evident by discolored plaster or drywall. If you don't have any observable mold, but are experiencing symptoms likely to be mold-induced, the mold could be growing in areas you can't see, such as the ducts of a heating/cooling system. In this case, the only way to know if you have mold spores is to test.

Many home inspectors or Industrial Hygienists can conduct air sampling to detect the presence of these spores in your home. If you have obvious mold, you can conduct a swab test that can be analyzed to determine the molds that are present. Testing is the only way to determine if you have a mold problem and what type it is. Take a copy of the laboratory report along with you when you visit your doctor or allergist. This will aid in determining a method of treatment.

If I have mold in my home, what should I do?

The first course of action is to determine why the mold is growing. Investigate any areas that are moist, and repair the source of the moisture. There could be a roof or plumbing leak, or groundwater leaking into your basement. Your air conditioning drip pan could have mold growing in it. Your air duct system could be contaminated with mold. If you see mold in your laundry room, chances are that your dryer is not properly vented to the outside.

Clothes dryers generate humidity and should never be vented inside the house. Mold will grow on any surface that provides moisture and food. Substances that are porous and can trap molds, such as paper, rags, wallboard and wood, should be thrown out.

How can I keep mold from damaging my home?

Adequate fresh air exchange. OPEN A WINDOW EVERY NOW AND THEN. Believe it or not, some people RARELY open their windows. This lack of air exchange leads to odors, and can create a perfect breeding ground for mold.

Repair water damage as soon as it is noticed!

Watch for signs of moisture, such as condensation on windows, cracking of walls and paint, loosening of drywall tape, warped wood or musty odors.

Install bathroom fans that vent humidity to the outside AND USE THEM. Consider having an electrician install a twist timer for your vent. Vent your clothes dryer to the outside. Clean any moldy surfaces as soon as they are noticed.

What can you do to control moisture?

Bathroom vents can remove excess moisture from showers and baths. Often people do not use the bathroom fan because it is noisy, or they don't want to let it run while they are gone from the house. We recommend using it! If not, leave the door open when you are done. Closing the door traps moisture in you bathroom which can cause a lot of problems. One great solution is to install a timer switch to control the fan after you exit the bathroom.

Kitchen vents, if vented to the outside, can remove excess moisture from cooking. Range hood fans that vent back into the room can remove smoke and odor by passing the exhaust through a filter, but they do not remove moisture from steam. If your house or condo has a recirculating vent (one that blows back into the kitchen), be sure to leave a window open. This is particularly important if you boil water or use a rice cooker.

Clothes dryers that are not vented properly can produce large amounts of moisture in a house or garage. We recommend that you do not use a lint trap. These are considered a fire hazard, and they allow lots of warm, moist air into you house or garage. Even if your dryer vents to the outside, periodically check the duct for obstructions or built-up lint. This is a fire hazard, and can lead to blockage which will force the dryer to vent into the house.

Ventilation of your garage, crawlspace and attic are a must. Do not block the vents in your garage. There are several reasons for this. In many houses the furnace, water heater, and washer and dryer are located in the garage. These all create heat in addition to parking a car in the garage. If moisture is present you can create a perfect environment for mold. Be sure you have enough ventilation for your crawlspace and attic. The general rule is that you should have one square foot of ventilation of every 150 square feet of crawlspace or attic space. If you have had a room addition added to your house, be sure proper ventilation was installed.

If you have turbine vents on your roof, DO NOT cover them with plastic bags in the winter. Air exchange in the attic is critical to the longevity of your roof. Plastic bags can trap moisture in the attic and deteriorate insulation. As the roof warms during the day from the sun, the damp moist environment you are creating can lead to mold.

Another big help in avoiding moisture problems is drainage, both around and under the house. This includes rain gutters and proper grading which direct water away from the structure. Good drainage will get rid of surface water and high ground water before they become a moisture problem. If you house has a raised foundation, consider installing a vapor barrier on top of the dirt.

Many homeowners will experience high humidity conditions in a new home the first year it is occupied. One reason for this is the amount of water that is present in the paint, plaster, concrete and other building materials. This moisture must be evaporated before the house thoroughly dries out. This problem usually corrects itself after the first year. If it does not and moisture problems persist, look for other causes of moisture problems and then correct them.

Additional information. Adobe Reader required for some links:

•  A Brief Guide to Mold, Moisture in Your Home
•  Molds, Toxic Molds, and Indoor Air Quality
•  Moisture in schools and commercial buildings

Our home inspections in San Diego are performed by trained inspectors, and conform to Nationally recognized ASHI standards and the NACHI code of ethics. Mold inspections are performed by AABIE or ESA trained inspectors.