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How Fast Does Mold Grow And What To Do About It

cleaning mold

Mold is a serious problem for residential and commercial properties. In fact, water is the number 1 destroyer of buildings and water is the source of mold.

So, how long does it take for mold to grow? What should you do about it?

In this blog post, we are going to answer just that, but first, we should discuss how mold starts.

How Mold Starts

Mold grows through two things: food and moisture. Food can be from dust, drywall, wood, or any organic substance. Moisture can be related to plumbing leaks, water intrusion, roof leaks, or even high humidity.

Therefore, mold can start growing in as soon as 24 – 48 hours of coming into contact with the right moisture level and organic substance.

Mold can easily continue to grow on materials and in the air if the conditions are right.

Roof leak leading to mold on ceiling

How Fast Does Mold Grow?

If items in a home continue to stay wet, including the air (i.e. high humidity), mold can persist and spread to other items.

Once started, mold can colonize in 3 – 12 days. From there, mold can become visible after 18 – 21 days.

What To Do About Mold

First off, prevention is key. A homeowner or commercial property owner should conduct yearly inspections. That way, leaks or moisture problems can be solved before it becomes a more serious issue.

In addition, a property owner should consider a mold test or inspection. Often times, mold can spread through the air causing a problem to go unnoticed. We conduct mold testing and inspections in the Tampa Bay, FL area.

Before jumping in, we want to recommend to where the proper personal protection equipment. This includes a mask and gloves.

1. Find The Source Of Moisture & Make Repairs

The first step is to find the source of the moisture. Is my A/C keeping the humidity in my home below 50%? It is coming from a roof leak? Is there mold around my A/C? Or perhaps your window is leaking? Our mold inspections help you find the source of mold.

Next, you have to repair whatever is not functioning. If you do not stop the source of moisture, your mold problem will persist. Therefore, see if you can repair the issue yourself. If not, call a professional to repair it for you.

2. Calculate The Area Affected By Mold

After finding the source of moisture and creating a plan to repair the problem, you should calculate the area affected by mold. You can do this by opening drywall, removing carpet, or possibly checking inside ducts with a flashlight.

After viewing the area affected by mold, calculate the area affected. If the area is greater than 10 square feet, you will need to call a professional. If the area is smaller than 10 square feet, you can use some home remedies to clean the mold yourself. However, remember, you need to stop the source of moisture. Otherwise, the mold can return.

3. How To Clean Mold Yourself

After you stop the source of moisture (or schedule someone to make repairs) and you know the area affected by mold is less than 10 square feet, you can begin cleaning the mold.

The first step is to dry everything out. This might involve removing wet insulation, using a dehumidifier, removing wet carpet, or opening up drywall.


Next, you will want to scrub the area down with a 50/50 solution of vinegar and water. Some people might recommend bleach, however, bleach can be too harmful on us humans.

After scrubbing the area down with vinegar and water, run a dehumidifier and a HEPA filter through the room. You can purchase a nice HEPA filter/fan or just replace the filter in your air handler with a HEPA filter like this one, just be sure to purchase the right size for your air handler.

Finally, check back in with the area each day. The mold spores should gradually disappear. If after a week the problem persists or grows, call a professional.

Once the mold spores are gone, you can replace the insulation or drywall.

If the problem persists after a week or more, or the mold grows, contact a professional to help you.

Final Thoughts

Mold grows through moisture and organic substances. It can begin to grow within 24 – 48 hours of coming into contact with the right conditions. Then, mold spores can become visible within 18 days.

An area of mold that is less than 3 feet by 3 feet can be cleaned by the homeowner. However, any larger, should be repaired by a professional.

After cleaning a mold issue, we recommend conducting mold testing to be sure all of the mold is removed. Have a question about mold? Comment below!

Call Waypoint Property Inspection to inspect your home in Tampa, St. Petersburg, Lakeland, Orlando, Palm Beach, Ft. Lauderdale, and surrounding areas.