We see more extensive problems with basement mold than in any other part of the house. (Attic mold and crawlspace mold are next in line.). There are three primary reasons for the prevalence of basement mold:
- After about 20-30 years of age, many building foundations made from concrete begin to see some cracking, which leads to water penetration. (Mold requires water to germinate.)
- In recent decades, many homeowners decided to “finish” their basements. In older homes, many of these basements were never truly designed to be finished. They are not water-tight, and many homeowners didn’t bother to water proof their basements prior to building them out.
- Sump pumps. We see more basement flooding as a direct result of sump pump failure than you can imagine.
Basement Mold Solutions
The basement mold problems we see with respect to the first two reasons are relatively small and localized. This makes sense when you think about it – a crack in the foundation will lead to a small water leak along the perimeter wall of your basement (eventually getting bigger), which will dampen the local interior drywall, which will lead to mold.
The best way to fix a crack in your foundation is to have it sealed/filled by a qualified professional. We also highly recommend walking around the outside perimeter of your home, making sure that there are no pools of water collecting against your house and making sure that your gutters drain at least 6 feet away from the house.
The basement mold problems we see with respect to sump pump malfunctions (#3 above) are often disastrous because they usually involve flooding of the entire basement. Even 1 inch of water in your basement is enough to cause thousands of dollars in damage because once the carpet and drywall get wet they are difficult to properly dry out (especially behind the drywall). It can be done, with many industrial air-movers/fans and dehumidifiers, but many homeowners don’t take the proper steps. Even when they think the basement is dry, it’s probably not, which will inevitably lead to mold.
Many homeowners don’t really know what their sump pump does or how exactly the sump system works, which is critical to understanding why a quality sump system is important.
A sump system is basically a drainage system. There are drain pipes around the perimeter of your home’s foundation that lead groundwater into your sump well (the drain pipes prevent groundwater from forcing its way through your foundation via cracks). The water is then “ejected” from the well, usually to the outside far away from the house, by your sump pump. So if the sump pump malfunctions, then those drain pipes are basically one-way rivers of water directly into your basement. You’d be surprised at how fast your basement can flood!
Sump pump malfunctions can be caused by both a broken sump pump and a power failure (during a storm).
We recommend buying the highest quality sump pump your money can buy. Trust us – don’t skimp on your sump pump. It’s not worth saving $100 when a broken sump pump can cause thousands of dollars in damage. We also recommend installing a battery back-up system. They cost a few hundred dollars extra, but they are worth it. Think about it – it is not a matter of if but when the power goes out because of a storm, right? So don’t lose sleep over a power outage; get the battery back up and keep your basement dry and mold free.
Relative Humidity Causes Mold Problems, Too
While most people recognize that flooding can lead to basement mold, what is far less obvious is that mold can just as easily form from drops of moisture resulting from high levels of humidity even in the absence of flooding. Ideally, relative humidity levels should be in the range of 30% to 50% throughout your home. As relative humidity rises to 60% and above, mold growth may occur.
Inexpensive relative humidity readers can be purchased at your local hardware store (Other Mold Gadgets).
By relative humidity, we mean the ratio of the amount of moisture contained in the air to the maximum amount of moisture the air can hold at a specific temperature. When the air reaches 100% relative humidity at a given temperature, the air is saturated and moisture forms. (50% relative humidity means the air is holding half the amount of moisture it can at a specific temperature before it reaches its saturation point.).
Relative humidity can be raised by increasing the amount of moisture in the air or by lowering the temperature since colder air can hold less moisture before it becomes saturated than hotter air.
If relative humidity starts to approach 60%, mold growth can occur. Given that a basement is underground, relative humidity levels can quickly rise in a basement relative to other parts of the home above ground.
Closets, storage rooms, closed off areas, windows, exterior walls/corners in basements are especially prone to moisture problems resulting from higher relative humidity or for that matter on all levels of the home. The only ways to eliminate moisture in these areas is either through source control (e.g. eliminating cracks in foundation), air exchange (e.g. replacing moist interior air with dryer exterior air through natural or mechanical means) and/or dehumidification (e.g. using dehumidifiers).