How Quickly Can Mold Grow After Water Damage and Why Immediate Action is Crucial
- Raquel Mendes
- 18 minutes ago
- 5 min read
It always starts the same way: a small leak under the sink, a dishwasher overflow, or a heavy rainstorm that seeps through your basement floor. You clean up what you can see, maybe set up a fan, and think the problem’s solved.
But beneath the surface, something else might be happening,—something quiet, hidden, and fast-moving. By the time most homeowners realize what’s going on, it’s already too late.
Mold.
It’s one of the most common and costly consequences of water damage. But how quickly can mold really start to grow? And more importantly, how fast should you act before it spreads?
Let’s uncover what really happens after water damage, what you can do to protect your home, and why hiring certified professionals makes all the difference..
The Hidden Danger After Water Damage
When water enters your home, it doesn’t just stay on the surface. It seeps deep into porous materials like drywall, carpet padding, insulation, and even the wood behind your walls. These areas trap moisture, creating the perfect conditions for mold to grow.
You may not see anything right away. The air might smell a little musty, or your floors may feel slightly damp. But inside those materials, mold spores are already waking up and beginning to multiply.
Most homeowners underestimate just how fast this can happen, often thinking it takes a week or two. The truth? It happens much sooner.
🕒 How Fast Can Mold Actually Start Growing?
Once moisture and warmth meet organic material, mold can begin to form in as little as 24 to 48 hours.
That’s right—within just two days of water exposure, mold can start spreading through your home. And once it begins, it doesn’t stop easily.
Even a small leak or spill can lead to:
Mold growing behind walls or under flooring
Musty odours throughout your home
Damage to drywall, insulation, and framing
Serious health issues if spores spread through the air
💡 Pro Tip: Health Canada advises addressing any water damage as soon as possible to prevent mold growth and protect indoor air quality. The sooner drying begins, the lower your risk of contamination.
⚠️ Why Immediate Action Matters
Every hour counts after water damage. Acting quickly isn’t just about saving your property; it’s about protecting your health, your investment, and even your insurance coverage.
1. Health Risks
Mold exposure can trigger serious health symptoms, including:
Coughing, sneezing, and eye irritation
Aggravated allergies or asthma
Headaches and fatigue
Respiratory issues in vulnerable individuals (children, the elderly, and immunocompromised)
2. Structural Damage
Mold feeds on organic materials like drywall, wood, and even certain paints. Over time, it weakens the structure of your home, leading to costly repairs or unsafe living conditions.
3. Higher Costs Over Time
The longer water sits, the deeper it seeps. What starts as a small cleanup can quickly become a full-scale restoration project. Acting immediately saves time, stress, and money.
4. Insurance Complications
Most insurance companies expect homeowners to take reasonable steps to prevent further damage. Waiting too long to act could result in reduced coverage or denied claims.
🧰 How to Respond to Water Damage Immediately
If you’re wondering, “How fast should I fix water damage?” The answer is simple—right now. Here’s what to do as soon as water damage occurs:
Stop the source. Turn off the main water line if it’s a burst pipe or leak.
Remove standing water. Use a wet/dry vacuum or mop up excess water.
Improve airflow. Open windows, use fans, and set up dehumidifiers.
Inspect hidden areas. Mold loves dark, enclosed spaces—check under carpets, behind walls, and inside cabinets.
Call certified professionals. If moisture remains or damage is significant, contact them immediately.
🏠 Why Choosing the Right Company Matters
Not all restoration companies are created equal. When it comes to your property and your health, certification and experience truly matter.
At ACI Restoration, we go beyond standard cleanup—we restore your property with precision, safety, and long-term protection in mind. Here’s what sets us apart:
✅ Zero Cost to You—We handle the entire insurance process and ensure there are no out-of-pocket expenses for you.
✅ Certified & Qualified Experts—Our team holds multiple professional credentials:
IICRC Certification in water damage and mold remediation.
Builder License and Architectural Technician certification.
HCRA Authority credentials for compliance and building expertise.
✅ 24/7 Emergency Response—Water damage doesn’t wait, and neither do we. Our team is available day or night across Burlington, Hamilton, Oakville, Mississauga, Guelph, and surrounding areas.
✅ We Do It Right the First Time—With the right tools, knowledge, and certifications, we ensure your property is not only restored but also protected from future issues.
✅ We Advocate for You—From start to finish, we work with your insurance company so you can focus on what matters: getting your home back to normal.
📞 Stop Mold Before It Starts—Call ACI Restoration Today
In just 48 hours, water damage can turn into a full-blown mold problem. Don’t wait until it spreads—call ACI Restoration before you call your insurance provider.
📱 Call now at 1 (289)865-1213 or book your free consultation to get help fast—at zero cost to you.
✅ Serving Burlington, Hamilton, Oakville, Mississauga, Guelph, and surrounding areas.
At ACI Restoration, we don’t just repair damage—We bring your property back to life while maximizing ROI and minimizing risks.
💬 Frequently Asked Questions
Can mold start growing overnight after water damage?
It depends on temperature, humidity, and how quickly the area is dried. Under ideal conditions, mold can begin forming within 24 to 48 hours of water exposure.
Even if you don’t see it, spores may already be active inside walls, flooring, or insulation. Because mold grows fast in dark, damp spaces, early drying and professional inspection are key to stopping it before it spreads.
Can I clean up water damage myself?
You can handle small spills or minor leaks, but larger or repeated water damage should be left to professionals. Water easily seeps into hidden areas like wall cavities, flooring, and substructures where it can’t dry on its own.
Certified technicians use industrial dehumidifiers, moisture meters, and thermal imaging to locate and eliminate trapped moisture, preventing future mold growth and structural damage.
Does homeowners’ insurance cover mold removal?
You should always call ACI Restoration before contacting your insurance company. When water or mold damage occurs, every minute matters, and how the situation is handled from the start can determine what your insurance will actually cover.
Many homeowners make the mistake of calling their insurer first, which can lead to partial coverage, delays, or out-of-pocket expenses if the damage isn’t properly documented. At ACI Restoration, we take care of everything from the beginning: we inspect, document, and report the damage professionally to ensure you get full coverage without paying out of pocket.
Our certified team works directly with your insurance provider to streamline approvals, maximize your claim, and remove the headache of dealing with paperwork. We protect your property—and your wallet—while making sure restoration is done right the first time.
What are the signs I might already have mold?
A musty odour is often the first sign, followed by dark stains or discolouration on walls, ceilings, or flooring. You may also experience allergy-like symptoms sneezing, coughing, or congestion that worsens indoors.
Other warning signs include bubbling paint, warped materials, or areas that stay damp even after cleaning. If you notice these signs, contact certified mold specialists to inspect and safely remediate the problem before it spreads further.
Where does ACI Restoration provide service, and when are you available?
ACI Restoration proudly serves homeowners and businesses across Burlington, Hamilton, Oakville, Mississauga, Guelph, and the surrounding areas. Whether it’s water damage, mold removal, or fire restoration, our certified team is always ready to respond when you need us most.
We operate 24 hours a day, 7 days a week, because property damage doesn’t wait for business hours, and neither do we. When emergencies strike, you can count on our experts to arrive quickly, assess the damage, and start restoring your property right away.
Day or night, ACI Restoration is here to protect your home, your health, and your peace of mind.