Questions About Indoor Mold: Answered

Questions About Indoor Mold: Answered

Where is mold found?

Mold spores are found everywhere all the time – indoors and outdoors. It’s just part of our natural environment and is a very important and beneficial part of our ecosystem because It helps break down organic waste.  We allow mold spores into our homes every time we open a door or window, and it hitches a ride on our clothing or skin.  But mold needs three things to thrive in any environment: 1) Air. 2) A food source. 3) Water.  The only thing we can reasonably control in that triangle of life is the water source.  The problem comes when we have abnormally high moisture conditions inside a home.  This can allow mold spores to grow and colonize.  Unless corrective actions are taken, the mold can quickly take over an area of increased moisture or humidity by shedding new spores into the air which will come to rest on surfaces and begin the cycle again – assuming the 3 conditions are met. The sources of moisture could be a leak (roof, foundation, plumbing, siding), condensation (due to poor temperature control, improperly or poorly installed HVAC systems, missing insulation in walls or ceilings, improperly installed insulation or vapor barriers, poor construction techniques, etc.), and also high humidity (due to foundation type, exterior drainage conditions at the foundation, poor air flow, oversized AC systems, heavy plant presence inside the home, poor use of vent fans in bathrooms, large aquariums, etc.)

What does mold look like?

Mold cannot be seen – it’s microscopic. What we can see are symptoms of mold on surfaces. The discoloration you see are waste products created during the mold’s life cycle. The appearance and color change depending on what the mold is feeding on, the moisture content, and the stage of its life cycle.  You might see colors of black, gray, yellow, white, green, blue, red, orage, purple, and so on.  So, visual signs of mold would be discoloration and raised structures growing out of the wall. If you take a flashlight and shine it parallel onto a surface, you can sometimes see the raised structures that you wouldn’t necessarily see with the naked eye.  Often times, there can be a smell associated with mold activity – commonly referred to as a “musty” smell.  Make no mistake though, just because you do not smell it, it does not mean that mold growth is not present or that mold spore levels are not elevated in the air.  Only sampling and analysis from a lab can confirm this.

How long does it take mold to become an issue?

The short answer is: Not long under the right circumstances.  For instance, you could fill a basement with water, drain it all out, dry it within 48 hours, and you may not get any substantial mold growth. Just like a seed, it takes time for mold to germinate.  On the other hand, if a house was sitting in two feet of water for two weeks, there would probably be so much mold growth that the house would need to be gutted.  For a better understanding, visualize the following:  If you put a flower seed in an empty and sealed plastic sandwich bag, it does nothing. You must first allow air to enter the bag, then add a food source (soil), and finally, water it and wait. For mold, it usually takes 24-48 hours to come to life, and given the right conditions, it can spread quickly.

What are the side effects of being exposed to mold?

It can depend on the individual, the type of mold, and the exposure length.  Although there are around 100,000 species of mold, there are only three basic categories of mold: 1)Allergenic. 2)Toxigenic. 3)Pathogenic.  Most molds we encounter in our homes are considered allergenic, but this does not mean they cause allergies.  It simply means that individuals that are susceptible to allergic reactions might be more affected by these molds.  There is one primary toxigenic mold that can be found in homes, and that is Stachybotris – the “black mold” that everyone hears about.  Toxigenic molds can be more harmful to some people because of the toxins they emit which can cause serious illnesses.  But remember, just because you see black discoloration, it does not necessarily mean that you are seeing evidence of “black mold.”  Pathogenic molds are those that can cause an infection in someone, even if the person is in relatively good health.  Elevated levels of any mold can be a health concern for some people. It depends on their immune systems and their allergic responses. For instance, If someone who does not typically have allergies is exposed to high levels of mold over a period of time, they can become allergic and develop headaches, a runny nose, itchy eyes or skin, a cough, or even asthma, which is why any suspected mold issue or moisture issue should be addressed regardless of the presence or absence of visual or olfactory evidence. Long-term and short-term effects can be very subtle to some, but more serious to others depending on the individual.  Persons with compromised immune systems can even die from complications due to mold exposure.

How can I know for sure if I have a mold issue?

The only way to know if you might have a mold issue is by having a qualified professional evaluate the property conditions and take samples – usually air and surface samples – to submit to a lab. Some of the highest levels we have found indoors were in homes with no visible or olfactory symptoms.  We have also tested fuzzy “growth” structures only to be told by the lab that no mold was present.  Areas of discoloration on the surface can be sampled using swabs and/or tape lifts, and comparative air sampling can be done as well and is usually highly recommended. When it comes to taking air samples (indoor samples and, ideally, an outside control sample), we have to consider the volume of area being sampled and the layout of the structure. If we sample an enclosed space that’s only 200 square feet, other parts of the house are not being tested. Air samples are really only considered representational of about 1,000 sq.ft. of relatively open space.  So, If we sample one side of an open-concept basement that is 2,000 sq. ft., it is possible that we would not detect elevated levels on the other side of the basement (just like radon, which is a whole other blog post). If surface discoloration is observed, the industry standard and recommendation is to sample both the surface and the air.  Let me explain why.  If the air sample is found to be elevated with a particular mold, such as Penicillium/Aspergillus, but the surface sample shows Cladisporium, it is reasonable to assume that there is another source of the elevated mold spores that has not yet been identified. If the two samples show the same mold, it is reasonable to assume that by correcting the visible issue, the elevated spore count in the air will also be taken care of. We won’t know that for sure, but that’s why it is also important to perform post treatment sampling to be sure levels have been reasonably reduced.  Without comprehensive sampling, we cannot get the best picture to determine the best treatment plan.  It’s like taking only one word from each paragraph of this blog post to come up with an outline of the key points and ideas, when you really need to take at least a few sentences of each paragraph to even come close.  In addition, If you have a mold inspection contingency in your home purchase contract, and you’re asking that the sellers remediate a mold issue, make sure that you also ask them to have qualified people find and fix the underlying moisture issue (if not already identified in the home inspection), or the mold is likely to return in the future. You have to resolve the moisture issue in order to prevent the mold problem – remember the triangle of life from the first paragraph?

What is the best way to determine if I have mold in my crawl space?

If the crawl space has open exterior vents, testing for mold in the crawl space by taking air samples is not recommended. The crawl space vents allow continuous air exchange with the exterior. As a result, air sampling for mold inside the crawl space is not a reliable way to determine if mold levels are elevated in that space. The preferred method is to perform surface sampling on any discolored areas that could indicate the presence of mold growth within the crawl space. In addition, commonly accepted industry standards would suggest performing air sampling in the living spaces adjacent to or above the crawl space to determine if potentially elevated crawl space mold levels are affecting the living zone.  Last, but not least, performing air sampling in unconditioned spaces such as crawl spaces and attics usually results in high levels of airborne dust and debris clouding the sample. If too much debris is present in the sample, laboratory evaluation may be inconclusive. We recommend you consult directly with one of our mold testing specialists to determine the best course of action in your particular situation. Regardless of the mold testing results, any conditions in the crawl space or at the foundation that are conducive to elevated moisture or water entry should be corrected to prevent future mold growth and to reduce the risk of deterioration of building components.

If you suspect you may have a mold issue, or you’re curious and would like to do some testing, give us a call at (301) 938-9100. We would be happy to discuss your options and determine what the best solution is for you!