Tips on Surveilling a Home to Find a Healthy, Mold-Free Living Environment

by Dr. Susan Tanner, MD

Several years ago, I decided to obtain a real estate license. At the time, my goal in doing so was to help some of my patients find “healthy homes” as this quest seemed to be a needle in a haystack endeavor–especially for those patients needing to find a mold-free home to properly heal.  Needless to say, my real estate journey became quite the interesting one as it gave me the opportunity to see first-hand what the real estate market was like as well as the ability to meet and learn from home and property inspectors of all types.

Today, I want to share with you some of my findings from my real estate adventure.  Before I begin, though, let me add that I am NOT an expert in buildings or mold inspections. I am more of a body expert who knows a bit more than the average Joe about buildings. Hopefully, with what I do know, I can suggest some things that may help you to discern when to walk away or when to call an expert if you are buying, renting, selling, or simply evaluating the health of a home.

Some of the Real Estate “Rules” I Thought I Knew Don’t Always Hold Up

When it comes to human health and building practices, it is probably best to throw everything you think you know out the window. In other words, some of the supposed “rules” don’t always hold up in real life; there are exceptions (almost) always. Let me elaborate:

1. Grade of the house –   In general, homes lower than street grade have the issue of water runoff as water does flow downhill, especially in older homes with block foundations. If water is constantly running toward a home’s foundation and soaking into it, then water entry through the cement block can often be an issue. However, I have seen homes in which you would think there would be an issue and there was not. Why? The downward grade of the property continued behind the house, and water was diverted via excellent drainage around the house so as not to meet the foundation. Thus, my general advice of “never buy a house in a hole” can have some exceptions.

2. Age of the house – The assumption that older homes, even historic homes, should be avoided as current building methods are better than older ones does not always hold true. I am not denying that some older homes, even in very pricey neighborhoods, do have big mold problems.  It is often thought that this occurs because the insulation, windows, and wall materials are not able to handle the indoor humidity gradient once central HVAC is added.  But, this is not always an issue. For example, when proper insulation, dehumidification, and possible previous water intrusion are handled properly, then the chances of mold are greatly lessened in an older, well-built home because the building practices were often better. Existing mold in older homes can often be treated and is sometimes more straightforward, although it may be with large effort and expense as with any remediation.  Obviously, older homes have the burden of history and historic water damage, leaks, etc., but I must add that new construction is not always superior.  In new homes, mold impacted sheetrock, to a staple inadvertently shot into PVC pipe creating slow and indiscernible water leaks for long periods, to poor drainage, to improper sealing or insulation, new construction can definitely have mold. In other words, shiny and new do not always mean mold-free.

3. Crawl spaces and basements – Either or both can have moisture or water intrusion if not high and dry. In the cases of dirt crawl spaces, for example, not having a good moisture barrier in place makes for an almost certain mold problem. One might then think then that the best option is a slab foundation, but again, that is not always the case. If the home’s foundation has not had its own vapor/moisture shield put down before the flooring is installed, then it is still quite likely that mold can grow under the floors through the wicking up of ground moisture through the slab.

7 Things to Pay Attention to When Evaluating the Health of a Home

Now that we have covered a few home evaluation topics that are not as straightforward as you may have thought, I want to address some that are. The following list comprises 7 of the most important things to look out for when you are looking for a home to rent or to buy:

1. Tree cover – I love trees. A home in the woods holds an appeal for sure.  However, if there is a large canopy of trees over the roof of the house, then there can be an inability for the roof to dry after rain or even with the extremes in outdoor humidity in some locations.  A wet roof can lead to increased mold growth in attics. Additionally, heavy tree cover can cause more debris such as leaves and pine straw to end up on the roof which can affect water runoff and clog gutters. Clogged gutters can then cause water to leak into the soffits and mold to grow.

2. Gutters and downspouts – These must be in good repair and kept clean with downspouts diverting water away from the home’s foundation. Additionally, keeping plant debris such as leaves and dead foliage away from the foundation also allows for water to flow away from the house and not soak into it.

3. HVAC units – These can be problematic from several standpoints. During a home inspection, I do think that it is important to remove the cover from the unit and inspect the coils.  If condensation has built up over time, then the coils and the plenum, which covers the coils, may have a significant build-up of mold.  This mold then blows all over the home when the unit is used.  I am shocked by the companies that offer duct cleaning without even looking at the possible source that may have caused the duct issues in the first place.  Another thing to think about is where the HVAC units are placed.  If they are in a damp crawl space, then there is likely going to be a mold issue.   A recent thing I saw in an older home was an attic renovation (likely not permitted) in which the HVAC return was in the unconditioned attic.   Imagine all that humidity that was then being sucked into the unit.  And yes, there was mold all over the coils.  The pan under the unit was also full of rust, mold, and insect parts too. If you see mold on the outside of a mechanical system, and evidence that the system has not been maintained, you can bet it is dirty inside and blowing all of that filth all over the home.

4. The area behind the refrigerator – Leaks in the water line for icemakers are not all that uncommon. Even when replaced, there may still be damage to the wall or floor that has not been addressed where mold has been allowed to grow.

5. Blown-in insulation – While used commonly, blown-in insulation is very dusty, and gets caught up in the air systems, creating more house dust.  Dust is a “magic carpet ride” for mold and toxins, and fiberglass does not do any favors for your nasal mucosa.  Batted insulation or foams are, in general, better for widespread use.

6. Damaged flashing around chimneys and vents; missing shingles or damaged/old roof materials – All of these may be allowing water leaks or signs of historic water intrusion/damage. And, where there is water and building materials, there is almost always mold.

7. Siding, stucco, brick, stone – Which building material is best? There is no simple answer as any and all can be just fine as long as it is in good repair, sealed, and properly installed.  In general, trying to avoid synthetic stucco may be a good idea as there were many cases of stucco allowing a “wicking” of water from the ground into the walls and subsequent damage.  If several feet of stucco has been removed near the ground, treated, and replaced with brick, concrete, or other materials then it may be ok, but also check around windows and doors for disintegrating materials allowing water and rot.

The above is not an exhaustive list of things to watch or look for but gives you a good checklist to go through as a potential home buyer, renter, or seller if you are listing. Additionally, the use of a powerful halogen flashlight to look for mold growth, and a moisture meter to check floors and walls are simple tools that can help your investigation.   While you may not be able to remove HVAC covers and inspect, the use of mold plates for simple testing while viewing the property while the HVAC is running may help you determine if there is a mold issue needing further investigation.   If you are mold injured already, I implore you to hire a good mold inspector or indoor environmental professional to look at and test any house that you are considering buying to avoid costly mistakes.  I promise you, it is money well spent.

Speaking of testing, mold screening plates are a handy tool to monitor your own home as well as any potential purchase or rental.  The plates do require one hour of time to sit for a proper test and getting permission from the selling agent or owner would need to be done prior.  But, if management or the owner resists, then this may be a sign that this is not the home for you.

Finally, I would be remiss if I did not mention something that has weighed heavily on me in the last year or two.  In general, I found that many of my patients felt better when they were near the ocean, the thought being that the high humidity of the beach environment was mitigated by the antifungal properties of the ocean/salt air.  This is true to some extent but after obtaining my Florida real estate license, I have found that beach properties are quite susceptible to mold and need the same attention to detail that we insist upon in other environments. The ocean air is and can be quite wonderful, but if you spend a lot of your time indoors with a contaminated HVAC system, then you will get nowhere fast.  The devil is, indeed, in the details!  As long as we have central, ducted HVAC systems in indoor spaces, mold growth must always be suspected and surveilled for. There is no such thing as a “perfect environment”, but you can certainly make the most of the environment you have by always being mindful about water intrusion, humidity, and structural integrity!

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