Mold Inspection Tips For Homeowners

I once received a call from a potential mold inspection client who feared that she may have hidden mold in her walls. She was concerned about possible hidden mold because a mold inspector told her that the ants observed in her property were a very likely sign of hidden "house mold" because ants eat mold.

Forget about house ants

Before we discuss a few basic tips on how to look for mold and moisture problems around the house lets talk about how not to find mold. Do not depend on ants to let you know if you have mold. In my home state of Florida as well as in the rest of North America ants are not a sign of mold infestation in your house. They are a sign that you have scraps of food or droplets of water in the house that the ants have discovered.

What about leaf cutter ants

Some ants eat mold, but these ants are not found in our homes. They do not even live in the United States. These specialized ants (called leaf cutter ants) live in large, underground colonies in the jungles of Central and South America. Furthermore, these ants do not enter people's houses looking for mold not even in the jungles of Central or South America. They tend to their own private gardens of cut-up leaves covered in fluffy, white mold in underground mold farms. They only consume the mold that they raised in underground mold farms they build, and they only grow and eat a very few specific species of mold. If there are any ants in Florida that eat house mold, I have never seen one - despite having done home inspections since 1993 and mold inspections since 2003. I have seen lots of homes, lots of mold, lots of ants and never once have seen ants in the vicinity of the mold. Most ants probably don't like house mold anymore than humans do because of the natural mycotoxins, beta glucans, allergens, and volatile organic compounds mold produces. In fact, it is predators (such as ants, other insects, and microbes) that prompt molds to produce many of the noxious chemicals most house molds produce.

Check for odors

So what are some signs of mold? if you have had a leak then the first sign of mold may be musty / moldy odors in the vicinity of the leak, check for these odors. Of course you do not want to be looking for or sniffing for mold, or touching mold if their is even a slight chance that you may have a compromised immune system, allergy, asthma, or any other conditions that would put you at risk of a negative reaction resulting from any form of mold exposure. In addition this article in no way will equip you to conduct your own mold inspection, it is just intended to give you a few simple tips. If you suspect a mold problem contact a certified mold inspector.

Check for odors near your AC ducts

Another trick to check for mold in your house is to turn your AC off for a while, the longer the better but just several minutes will due if you have a serious problem. Next turn your AC back on and leave your thermostat alone for a while, turning it on and off to more than one cycle in several minutes can damage your compressor. Now immediately stand directly under the path of air flowing from a duct. If your AC unit or your homes ductwork is contaminated with mold you will smell the musty mold odors blowing in your face. Remember do not do this if you are asthmatic, allergic to mold, or have a compromised immune system, do not do this if their exist any chance that you may have any of the above mentioned conditions or any health conditions that could become a problem as the result of exposure to mold.

In ducts the odors build up when the AC is off and may dissipate after the AC has been on for a while. Please note minor moldy odors and minor mold contamination are not unusual in AC units and may not cause a problem for most people. Having a mold inspector sample the air from your ducts may not do you much good because mold in AC units is often vegetative, in other words in may be growing without producing many spores. Further investigation by having an experienced certified mold inspector inspect inside your AC may be of benefit.

Look for mold on AC registers and coils

Metal AC register grills become cold as air exiting your duct passes through them. If you have high humidity condensation may form on these registers. AC coils are designed to form condensation when you simply use your AC unit in the cooling mode; this feature helps the system to remove humidity from your air. AC registers in humid buildings and coils in any building have a good chance of forming a mold problem. The bottom sides of AC coils sometimes grow large amounts of velvety Grey cladosporium mold or clear jelly like bacteria masses, and AC register form black cladosporium mold. So check your AC registers & coils for mold.

Look for spots in basements and closets

Sometimes mold does not start as the result of a leak in your home but may occur as the result of humidity problems, in such cases the mold typically starts in areas with poor circulation such as in basements, closets, and bathrooms, and may spread if your homes humidity is above 60%RH to 65%RH. Mold growing on drywall in bathrooms is typically black cladosporium or it may be pen asp. In your homes closets powdery mildew like white or green spots of mold are common. To find these molds look for light spots on black clothes, luggage, and shoes, it does not show well on light colored clothes.

Look for spots on water damaged building materials

Small spots, smug marks, or a powdery residue in the area that became wet is a good indication of mold. Most mold spots are black, brown, green, or white. These initial growths of mold are typically very small at just a few millimeters across in the start. One way to tell a smudge mark, a bad paint job, or other marks and stains from mold is to rub it with a dry cloth. Most molds will at least partially rub off or smear and leave a streak mark on the surface. This is because mold is intentionally designed to be friable (easily broken) in addition mold spores are intentionally designed to detach easily for dispersal. Discoloration from scuff marks and paint etc will often not smear easily. Of course this method does not work all the time and is not full proof, but some times it is helpful to a degree in providing some preliminary info on what you may be dealing with. The best way to tell if a stain is mold is to send it to a lab.

Check window caulking,

Hidden mold inside walls is common and one of the primary reasons for hidden mold inside walls is window leaks. If you have even minor hairline defects in your window caulking it may let small amounts of rain water or sprinkler system water into your walls. Moderately or seriously defective caulking causes many mold problems in this mold inspector’s experience.

Inspect baseboards

When water enters walls if flows down and soaks into your baseboards and causes them to swell, when they dry they shrink. Swelling and shrinking causes baseboards to separate from the wall slightly, you will see a small crack between the top of the baseboard and the wall. Water in your walls that causes baseboards to separate from your walls means water in your walls that may have caused mold.

Check tack strips,

Tack strips under your carpet will become stained and rapidly rot if you have water entering your walls. Water in your walls means possible mold in your walls. Peeling your carpet back to see the tack strip located under the perimeters of your carpets may loosen or even damage your carpet, so if your carpet is important to you don't pull it up to check your tack strips.

Don't forget your wallpaper

If heavy wall paper is installed any moisture that enters these walls will become trapped behind the wall paper, moisture trapped behind wall paper mixed with wall paper glue is a perfect recipe for a serious mold problem. During mold inspections wall paper is not typically peeled thus hidden mold may not always be discovered but it is common to find mold hidden behind wall paper. The vast majority of moldy wall paper is on perimeter walls, as apposed to on interior partition walls.
Perimeter walls are the walls of a building that abut the exterior of a building; these walls receive moisture from cracks and defective caulking on the exterior side of the walls. Inspecting behind sections of wall paper may reveal large amounts of hidden mold.

If you think you have a house mold problem and are concerned about possible resulting health problems, do not only rely on the tips from this article, do not rely on hungry ants, cheap mold inspectors, or divining rods. Hire a professional mold inspector who utilizes moisture meters, humidity meters, borescopes, and air samples to detect mold problems in your home and who provides professional remediation recommendations.