What to Do When There’s Water Damage, Mold, & Mildew

Mold is incredibly common and can be found in many properties throughout the United States. In fact, roughly 47% of homes in the United States have some mold in them, according to the National Institute for Occupational Safety and Health (NIOSH). One reason for this is that mold grows quickly in indoor spaces exposed to moisture, damp air, and insufficient sun exposure.

Of course, some molds are great, like the kinds used to make different cheeses. However, the mold that grows in homes can cause health troubles, allergies, and permanent damage. Water damage mold can grow quite quickly and be extremely dangerous if you don’t get rid of it.

Let’s take a closer look at how water causes mold to grow, why it’s harmful, and how to properly test for it in your home.

1. Water Leaks in Your Home that Can Cause Mold

First off, how long does it take for mold to grow?

According to FEMA, it only takes 24 to 48 hours for mold spores to begin growing on damp surfaces. This is why you must be able to identify the common ways water can creep into your home and cause mold to grow. Let’s discuss some of the biggest culprits:

A. Roof Leaks

Small roof leaks may not seem like they would cause a lot of damage, but the destructive power of water should never be underestimated. A leaking roof doesn’t stop at just structural damage. It also poses serious health and safety risks.

Continuous water intrusion from roof leaks doesn’t stop in the attic, either. Water will often creep down from the attic all the way to the foundation if given the opportunity. This causes extensive damage along the way and creates more mold growth opportunities.

B. Flooding

If your home or basement is flooded, even just a little bit, you must test it for mold quickly. As mentioned earlier, mold spores only take a day or two to colonize. However, it could take weeks for the mold to become visible. Since flooding creates a humid environment, microorganisms from mold spores can fill the air and spread rapidly throughout a home.

C. Malfunctioning AC Units

When an AC unit is working as it should, it acts as a dehumidifier for your home. This means it cycles excess indoor moisture and removes it from your home. However, if your AC unit has a clogged drainage tube, it can start to leak water and grow mold both in and around the unit.

D. Damp Laundry

If your clothes remain damp for a few days, they can start to grow mold. This is especially likely to happen if you leave your moist clothes in a cool, dark place. Mold can spread to additional clothing items nearby.

It’s nearly impossible to remove mold damage from clothes, so you will likely end up having to throw them out. No tangible item is worth risking damage to your home or health.

E. Plumbing Leaks

Leaky plumbing can cause a variety of problems – including the eventual growth of mold and mildew. As pipes are typically located within the walls or behind fixtures, leaks often go undetected, causing moisture buildup behind walls, under flooring, and in ceilings.

By the time the leak is discovered, mold has often already begun to grow. Some common signs of undetected water damage and mold growth from pipe leaks are:

• Audible water dripping or rushing within the walls
• A general musty smell around the walls or flooring
• Visible discoloration on walls, ceilings, and baseboards

A mold inspector can perform mold testing with both indoor air quality tests and surface sampling to verify the presence of mold in a structure. These tests will help determine the species and quantity present so the mold remediation process used will be as thorough and effective as possible.

F. Other Ways Water Damage Mold Can Form

Here are some other ways water damage can lead to a mold infestation: 

• Condensation on the inside of a window
• Inside of roof gutters
• Pipe Leaks
• Spills that aren’t properly cleaned up
• Rooms without sunlight exposure (i.e., basement, attic, storage)
• Lack of good ventilation
• Failing to clean regularly in damp areas
• Crawl spaces and small, hidden areas that are never checked or cleaned

2. Can Mold Cause Health Problems?

There are thousands of different types of molds, some of which can cause allergic reactions, infections, cancer, and even death.

Exposure to toxic mold is especially dangerous to children and people with compromised immune systems. A person who is immunocompromised might develop a lung infection from mold or illnesses that lead to long-term issues and, in some cases, death.

Children are at a higher risk of developing respiratory illnesses from moist air and mold particles. In fact, according to the National Institutes of Health, one in four children is at risk of developing asthma from mold exposure.

Even healthy people can develop health troubles from indoor mold growth when it overruns their home, or they inhale large amounts of airborne spores. Approximately 15-50% of the population is genetically prone to developing allergies from mold as their bodies are unable to fight the toxicity.

Toxic mold exposure can cause the following symptoms:

• Anxiety
• Coughing
• Depression
• Eye Irritation
• Memory loss
• Respiratory Problems
• Runny Nose
• Skin Rash
• Sneezing

A. Harmful Mold Classifications

The most harmful types of molds are part of these three classifications.

1) Allergenic Mold

Allergenic molds cause or trigger allergic reactions. This can be especially harmful to people who have an underlying respiratory issue or those who are sensitive to airborne allergies.

2) Pathogenic Mold

Pathogenic molds can cause infections and worsen underlying health problems. If pathogenic mold is inhaled for long periods, it may cause lung infections such as bronchitis or pneumonia.

3) Toxigenic Mold

Toxigenic molds are some of the most common and dangerous to inhale. This mold likes to hide in the darkest parts of a home and can spread rapidly.

B. How can Mold Damage a Home?

Along with adverse health effects, mold can also damage your home by taking over large areas that require removal or even demolition to eliminate. It can be expensive to remove mold and may even require that you replace personal items and furniture along the way.

Mold can break down the wood, drywall, tiles, and other materials throughout a home. The national average cost for mold removal starts at around $3,500. This cost will be much higher for larger spaces or more complex situations such as crawl space water intrusion or water damage from a second story damaging the first floor. In that case, water restoration and mold remediation must take place for both levels of the property.

Consequently, the price for restoration will go up when there is more mold present, as it must be carefully removed. Identifying mold in your home early on can eliminate the need for expensive mold remediation and repairs, which saves you both money and overall well-being.

3. How Can You Test for Mold?

There are many ways in which you can test for mold on your own. You can purchase an at-home mold test from almost all hardware stores. However, you should be wary of the accuracy [JB3] of these tests. These tests have been known to give false results. In some cases, unopened test kits have even been moldy upon purchase.

Further, testing for mold is something that should be done by a properly certified, experienced mold inspector/hygienist as it is quite complicated or even dangerous. If you do not know much about mold, you may not read the results correctly. There is also the possibility of test result contamination if you do not follow the correct chain of custody during the testing process.

If your home was exposed to water damage and you believe it might contain mold, the best way to find out is through a professional inspection and testing. Unlike at-home tests, certified professional mold inspectors can accurately detect where the mold is growing, its source of it, and the severity of mold growth.

This is where we come in.GPMI is a professional mold inspection and testing service in Southern California. Our team of mold inspectors is all ACAC certified and specializes solely in mold testing and mold inspection rather than removal. We only use unbiased 3rd party laboratories to avoid any conflict of interest and provide the most superior mold testing services in Southern California.

We offer various types of mold tests:

• Direct Sample: Testing of a visible mold-like substance to determine which type of mold is present in the home.
• Wall Cavity: We will collect a sample from inside wall cavities between drywall panels to check for any presence of mold in this hard-to-reach area.
• Air Quality Testing: This tells us the type and quantity of mold spores present in the air.
• DNA/ ERMI/ SIM Mold Screen Testing: This test determines the scope and type of mold inside a home and gives us an idea of where it’s developed from.

After we thoroughly test a home for mold, we provide our clients with a detailed written report of our findings. We include what types of molds were found as well as any bacteria or allergens detected. We also include the scope of necessary work. If it turns out that your home needs repairs or mold removal, you will have to show this report to a professional mold remediation company.

In Conclusion:

Mold could be hiding in your home, putting you, your family, and your beloved animals at risk of illnesses. If your home has been exposed to water damage or moisture exposure, we recommend that you have a properly certified professional and experienced mold inspection company that only uses unbiased 3rd party AIHA-certified laboratories to inspect and conduct necessary tests. Comprehensive Mold inspections are accurate and can protect your family from living in an unhealthy environment.

To schedule a free consultation or schedule a mold inspection with GP Inspect, call (949) 328-5754 or contact us on our website.

Published: May 20, 2021

Updated: March 24, 2025