Water Damage Cleanup: 2 Tests For Assessing Mold Growth

If there's a problem with the plumbing at your home, your entire house may be vulnerable to water damage. On top of irreparable damages to household appliances and personal items, water leakages and flooding can also promote mold growth. Mold has the potential to cause health problems as it produces toxic substances known as mycotoxins. This is especially true if the spores are inhaled. Mold growth may not always be visible. Here are 2 tests to perform in order to analyze and assess mold growth after performing necessary water damage cleanup.

Testing Relative Humidity and Moisture Levels within the Home

Mold flourishes in humid environment. After a water leakage or flood, the humidity levels within your home may skyrocket. When dealing with water damage, you want to first and foremost assess the relative humidity and moisture levels within your home after the leakage or flood has been stopped. Measure relative humidity and moisture levels indoor with a hygrometer. There are many different types of hygrometers that can be used. Popular options include relative humidity sensors, condensation principle hygrometers, and "dew-point" probes.

Ideal relative humidity and moisture levels indoors will fluctuate based on the temperature outside. If the outside temperature is between 20 to 40 degrees, the relative humidity indoors should be 40% and below. On the other hand, if the outside temperature is between 10 to 20 degrees, the relative humidity indoors should be lower at around 35%. In the summer, the relative humidity levels indoors should never exceed 55%.

To reduce moisture levels and humidity indoors, purchase a dehumidifier. You should also consider turning on as many fans and ducts as possible. Keep all windows and doors open as well to allow air to circulate better. Make sure that the relative humidity of your home has returned to normal indefinitely before you close the windows and doors or turn off any fans. It's important to be extra careful because it only takes 24 to 48 hours for mold to grow.

Perform a Doormat Test

The problem with water leakages and floods is that the majority of the water will seep into the internal structure of your home. If the floors or the walls do not have proper vapor barriers, they become much more vulnerable to harboring mold growth. To determine whether you will need to call a professional to rip out the floors or the walls for a more extensive water damage cleanup, perform the doormat test.

To perform the doormat test, place a doormat onto the floor of a crawlspace, a basement or taped to a wall for a day or two before you remove it. If you observe moisture accumulating underneath the doormat, you can be sure that the tested area does not possess a proper vapor barrier. This indicates that water has seeped into the internal structures of your home, making it an ideal area for mold growth.

It also means that you'll need to contact a specialist to determine the extent of the water damage, and whether any renovations are required to fully repair any water damage that has occurred. If you fail to do so, mold may grow internally, and the spores can easily be distributed throughout your home by entering the air vents and ducts.


It's important to act quickly in the face of water damage. Even after you have done some water damage cleanup and removed any soiled items or furnishing, it's important to assess humidity levels and conditions within your home to determine whether it's still suitable for mold growth. By catching these problems early on, you could save yourself a lot of headaches in the future and also avoid many health concerns and problems.