A homeowner’s guide to identifying, cleaning, and preventing mold the right way
Mold on drywall isn’t just unsightly—it can lead to health problems and structural damage if left untreated. Whether you’re dealing with a small patch in the bathroom or an ongoing issue in the basement, understanding how to remove mold and prevent mold safely is key to protecting your home and your health.
At BRK Drywall, we’ve seen firsthand how mold can take hold—and how to deal with it properly. In this guide, we’ll walk you through everything you need to know: from spotting early signs to cleaning it yourself, and knowing when it’s time to call in the pros.
Understanding Mold on Drywall
What Makes Drywall Vulnerable?
Mold needs two things to thrive: excess moisture and organic material. Unfortunately, drywall checks both boxes. Its paper backing provides a food source, and it’s often located in areas like bathrooms, kitchens, and basements where humidity and leaks are common.
Left unchecked, mold can spread quickly and even hide behind the wall where you can’t see it. That’s why catching it early—and addressing the cause—is so important.
Common Causes of Mold
- Leaky plumbing or roofs
- Poor ventilation in bathrooms or kitchens
- Flooding or water damage
- High indoor humidity levels
- Improperly sealed windows or foundations
Even small leaks or daily steam from showers can lead to mold growth if there’s no ventilation or moisture control in place.
Health Risks of Mold Exposure
Mold isn’t just a cosmetic problem. It can cause symptoms like:
- Sneezing, coughing, or itchy eyes
- Worsened asthma or allergy reactions
- Fatigue or headaches with long-term exposure
Certain types, like black mold on drywall, are known to produce mycotoxins that can trigger allergic reactions and respiratory issues, especially in children or people with asthma.
If anyone in your home has breathing issues or a weakened immune system, getting mold under control quickly is especially important.
How to Spot Mold on or Behind Drywall
Mold doesn’t always announce itself with a bold black patch. Sometimes, the signs are more subtle. Here are how to spot the signs of mold behind drywall.
What to Look For
- Dark stains, discoloration, or speckled spots
- Peeling or bubbling paint
- Soft or warped drywall
- Musty, earthy odors that linger (yes, you can smell mold)
- Worsening allergy-like symptoms indoors
If you suspect mold but can’t see it, it may be growing behind the drywall. Professional tools like infrared cameras or moisture meters can help detect hidden mold.
Safety First: What to Do Before You Start
Before you clean mold, take proper precautions to protect yourself and prevent spreading spores to other areas of your home.
Protect Yourself
- Wear gloves, goggles, and an N95 mask
- Use old clothing or disposable coveralls
- Avoid dry scrubbing, which can send spores into the air
Prep the Space
- Seal off doors and vents with plastic sheeting
- Ventilate the room by opening windows (if weather allows)
- Set up a fan blowing outward to push air and spores outside
Dispose of any contaminated materials (like sponges or rags) in sealed trash bags immediately after use.
Step-by-Step: How to Kill Mold in Drywall
Step 1: Check the Mold Damage
Start by inspecting the drywall. If the mold appears to be surface-level and the drywall feels solid, you can usually clean it. But if it’s soft, crumbling, or moldy on both sides, it’s safer to remove and replace the affected section.
Step 2: Choose a Cleaning Solution
You don’t always need harsh chemicals. Here are a few effective (and affordable) options:
- White Vinegar: Spray it undiluted onto the moldy area. Let it sit for an hour, then scrub gently with a sponge or brush and dry the wall completely.
- Baking Soda: Mix a tablespoon of baking soda with water to create a paste. Apply it to the mold, scrub gently, and wipe clean with a damp cloth.
- Hydrogen Peroxide (3%): Spray directly onto the mold. Let it foam and sit for 10–15 minutes before wiping clean and drying.
- Commercial Mold Removers: Choose an EPA-registered product designed for use on drywall. Always follow the label’s safety directions.
Step 3: Scrub & Dry
Using a sponge or soft brush, gently scrub the visible mold until it lifts away. Avoid sanding the surface—it releases mold spores into the air. Once clean, dry the wall thoroughly with fans or a dehumidifier to prevent future mold growth.
Also Read: Is Drywall Effective for Soundproofing Your Walls?
When to Replace Moldy Drywall
Sometimes, cleaning just isn’t enough. Here’s when it’s time to cut your losses and replace the drywall:
- The mold keeps returning despite cleaning
- The wall feels spongy, warped, or crumbly
- There’s visible damage on both sides of the wall
- You notice a persistent odor even after cleaning
Replacing drywall might seem like a hassle, but it ensures you’re not just covering up a deeper issue.
Preventing Mold from Coming Back
Once you’ve removed the mold, take steps to prevent it from coming back.
Fix Moisture Issues
- Repair any leaks—roof, plumbing, or windows
- Check your foundation and basement for seepage
- Improve outdoor drainage to keep water away from your home
Improve Airflow
- Use ventilation fans in bathrooms, kitchens, and laundry rooms
- Keep windows open when the weather allows
- Add vents or fans in crawlspaces or basements
Control Humidity
- Run a dehumidifier in damp areas
- Keep indoor humidity below 50%
- Consider mold-resistant drywall (like green board) for moisture-prone rooms
Routine maintenance and air circulation go a long way in keeping your interior and exterior walls mold-free.
When to Call in a Professional
DIY mold removal is doable—but only to a point. You should call a mold remediation specialist if:
- The affected area is larger than 10 square feet
- Mold keeps coming back after repeated cleanings
- You or someone in your home is getting sick
- You suspect mold behind the walls or in multiple rooms
Professionals have tools to detect hidden moisture, safely remove contaminated drywall, and help ensure it doesn’t return.
Conclusion
Mold on drywall isn’t something to ignore—but it’s also not something to panic about. With the right steps, you can safely remove minor mold growth and protect your home from future issues.
Start by identifying the signs, using proper safety gear, and choosing a cleaning method that fits your situation. And when in doubt, don’t hesitate to bring in the pros.
At BRK Drywall, we’re here to help you every step of the way—from cleanup to replacement. If you need expert guidance or full drywall restoration, get in touch with our team today.
Also Read: The Importance of Proper Drywall Finishing for a Flawless Interior