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Absolutely home buyers should be concerned about molds in their prospective home. Especially when a good home inspector informs them that there are conditions in the house that may produce future out breaks of mold. Maybe there is a bargain to be had in the real estate transaction. A possible diamond in the rough provided the savvy buyers can identify the causes of the mold and prevent future outbreaks.
Lets start at the beginning.
The public image of mold is often misleading and far from the truth. And yes, certain molds are toxic to humans especially if the individual is sensitive or allergic to molds. However, keep in mind that molds are a large class of organisms that serve a very important function in the environment – they decompose and break organic matter as part of the nutrient cycle. They break down fallen leaves from trees and other detritus. Think of the mold that magically appears and grows on our bread if left uneaten for too long.
Molds are ubiquitous. They can be found in our cars, between our toes, the spores can be found floating in the air. The key to mold growth in our homes is a source of moisture and organic matter and humid environment, anything over 65% humidity will support mold.
Where are molds most commonly found in the home?
In short, mold can be found anywhere in the home provided there is a constant source of moisture, poor ventilation situation and organic surface for mold to feed on. It is even possible for mold to grow on dust covered surface where mold feeds on the dust.
Molds are often found in bathrooms because we have a source of moisture when we shower, a condition for poor ventilation and hence the humidity especially in the winter when we close the windows to keep the heat inside. And, we have a source of organic matter – the drywall, particularly around the ceiling because hot humid air tends to rise and hangs out at the ceilings when there is a lack of proper ventilation. Bathrooms are required to have either a window accessible to the exterior or mechanical ventilation to the exterior with a minimum of 50 cubic foot per minute (cfm) exhaustion. It is highly recommend that after a shower, to leave the bathroom exhaust fan on for about 30 minutes to complete vent the humid air to the exterior. A simple timer installed on the exhaust fan will handle that.
Other common areas to find mold is the basement or crawl spaces and attic spaces. The scent of musky dampness is a very good indicator that the environment has poor ventilation and highly likely will have mold somewhere. Often mold is growing behind wood panels, organic surfaces near the floor where the moisture is highest. In the attic, mold will grow right on the wood framing member and roof sheathing.
What all these places have in common is they have poor ventilation and a source of moisture. Basements and crawlspaces are often damp to begin with. The moisture comes from the ground as the foundation is made of cement which is porous. Efflorescence is a good indicator that moisture has moved from inside the cement and onto the surface of the cement. Attics with improper vent discharges often will result in mold growth. For example, bathroom vents, kitchen vents and even dryer vents can be improperly installed to discharge into the attic space instead of directly to the exterior. These vents exhaust moist indoor air supplying the attic with enough moisture to to support mold growth.
Mold is also commonly found in rooms that have an exterior wall where it can be cold during the winter season with insufficient or missing insulation. When the heat is turned on, warm air passes over the cold surface, often the cold corner of a room where the ventilation is poor, the warm air forms condensation on top of the cold surface. This provides enough moisture to support mold growth around those cold corners of the room. To remedy this is simple, ventilate the room. Make sure enough air is circulating the room and insulate the attic and exterior walls to rid the house of those cold corners.
What you should know to get rid of mold in the house.
A good home inspector will be able to explain in detail and in layman terms to their clients what they need to know about mold should the buyers wish to continue with the real estate transaction. What can be done? – depends on the extent of the damage. First, address the root cause. Where is the moisture coming from? Eliminate the source of moisture. Next remove and replace all affected building materials. Ensure there is adequate ventilation in the new construction.
If the extent of the damage includes structural members, this is where it is having such information is priceless as prospective buyer can determine financially if they which of continue, renegotiate the price or walk away from the real estate transaction. If the home buyer decides to proceed with the purchase, they should be fully aware of the risks involved. A good home inspector needs to explain in laymen terms the implications of the risk factors noted. Every risk factor requires a detail explanation to the client.
Superman has the super power of “X-ray” vision which allows him to see behind walls or inside houses. Imagine if you have that power before you buy your next house? Read more about infrared thermal imaging and seeing behind walls.
What other defects and damages can infrared thermal imaging detect that is not visible to the human eye? Moisture! How is that possible you ask? Remember that infrared thermal images display temperature difference. The image produced is a thermogram displaying surface temperatures relative to one another.
So why does the drywall under the window clearly show a cooler temperature? Recall that blue is cooler compared to red or orange. If the temperature was not significantly different, we would not look further into this. The mostly like two reasons include missing insulation behind the drywall or the drywall is moist. We use a moisture meter to eliminate the moisture issue, leaving the missing insulation the most likely explanation. However, if the moisture meter indicates moisture, we inspect the window well and window still closer for signs of moisture damage. We always confirm with a moisture meter reading before concluding moisture damage.
If the moisture meter comes up positive and the window still shows moisture damage, depending on how long this condition has gone on for and whether the immediate area has good ventilation or not, this could be good conditions for mold growth if left unchecked. Also, behind the drywall would definitely be subject to mold conditions as ventilation is nil plus the ample moisture supply.
A quick scan with the Flir B-250 gives the home inspector an idea of where to investigate further. The scan is non-invasive and does not damage the walls or any other part of the house. This makes the inspection fast, accurate and provides clients with proof of defect or damage.
In winter, when warm air is vented directly into the attic, the moisture in the warm air will condense. Over a season, that can add up to a lot of moisture in your attic and that creates an ideal condition for mold. Furthermore, the roof sheathing start to cup and rot. The moisture can also run down the ceiling and into the drywall, and again, this creates an ideal environment for mold and rot.
So what is mold? Simply put, mold is a fungus found pretty much everywhere on this planet. Ever left food out and after a week or so, the food grows fuzz around it? That’s mold. Aside from food spoilage, molds are microbes involved in all natural material bio-degradation. This also includes building materials such as wood framing members, sheathing, and drywall.
Molds are ubiquitous. Mold spores are a common component of household dust. However, when mold spores are present in large quantities, they can present a health hazard to humans, potentially causing allergic reactions and respiratory problems.
There are thousands of species of molds, all requiring moisture to grow. In the ecosystem, their role is to decompose. The term “toxic mold” refers to molds that produce mycotoxins, such as Stachybotys chartarum.
Mold around the house is found in damp, dark or steamy areas such as bathroom or kitchen, cluttered storage areas, recently flooded areas, basement areas, plumbing spaces, areas with poor ventilation and outdoors in humid environments. In addition, attics particularly with vents that improperly discharge directly into the attic are prone to supporting mold. Often time when I inspect an attic, it is common see a bathroom vent or kitchen vent discharge directly into the attic, and the framing immediately around the vent discharge is covered in black mold.
The key for mold growth around the house, as already mentioned, is a damp environment and a lack of ventilation. For the average home owner, visible mold is relatively easy to spot if you know what you are looking for. However, when mold is hidden behind drywall, a panel, storage items, or behind furniture attached to the wall it may be difficult to identify.
Identifying mold is beyond the scope of a standard home inspection. A good home inspector can recognize conditions the would support mold growth and report that to the client. And, if home buyers expect to buy a home free and clear of any mold, then don’t buy any home because as mentioned above, mold is ubiquitous. They are in your cars, on your clothes, in your hair, on your skin so on. We cannot control their presence, we can only control the environment to limit their growth.