Advice from a 40-Year Drywall Veteran
After four decades in the drywall business, I’ve seen just about everything, from homes so dry you could store paper in the attic, to basements with more humidity than a summer night in Raleigh. One problem that keeps cropping up, year after year, is mold on drywall. It’s sneaky, persistent, and if you don’t catch it early, it can become a costly headache.
In this post, I’ll walk you through what causes mold to grow on drywall, how to spot the signs early (even the ones that don’t scream “mold”), and what you can do to prevent it. And when prevention isn’t enough, I’ll explain why calling in a pro might be your best bet.
Where Mold on Drywall Comes From
Mold is a living organism that thrives in moist, dark, and warm environments—exactly the conditions that can sometimes develop behind your drywall.
Mold spores are everywhere, floating around harmlessly until they find the right spot to land and grow. Drywall, especially the paper facing, is made from organic materials that mold loves to feed on. Once it gets moisture, it’s off to the races.
Here are the most common culprits we see in North Carolina homes:
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Leaky pipes inside walls
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Roof leaks dripping down interior surfaces
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Basement moisture from poor drainage or high humidity
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Unvented bathrooms with regular steam buildup
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Flooding or storm damage (a big issue after hurricanes or summer storms)
Even brand-new homes aren’t immune if the drywall was installed before the structure was properly sealed or dried out.
How to Tell If You’ve Got Mold
Sometimes mold makes itself known with a musty smell, or visible black, green, or brown spots. But more often than not, it hides behind the paint or inside the walls where you can’t see it—at least not right away.
Here are some signs to watch for:
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Discoloration or staining on walls or ceilings
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Peeling paint or bubbling drywall tape
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Persistent musty odor, especially after rain or in high-humidity areas
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Increased allergy symptoms like sneezing, coughing, or itchy eyes when inside
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Soft or sagging drywall that feels damp to the touch
Unfortunately, by the time these signs appear, the mold may have already taken root. That’s why prevention and early action are key.
Why You Might Not Notice It Right Away
Mold doesn’t always announce itself with bold black spots. In fact, it often hides behind the wall. Here’s why:
Interior moisture issues are subtle – A slow drip from a pipe or condensation on a poorly insulated exterior wall may not be visible right away.
Drywall is porous – It can absorb water without showing clear external signs until the damage is well underway.
Paint can mask symptoms – Many paints (especially glossy ones) resist moisture on the surface, but they don’t stop mold from growing underneath.
HVAC systems spread spores – Central heating and cooling can circulate mold spores, making the issue feel like a seasonal allergy.
This is especially true in North Carolina, where we deal with both high humidity and the occasional freezing winter that can lead to condensation problems inside the wall cavities.
How to Prevent Mold Growth on Drywall
Here’s the good news: mold on drywall can be prevented, and it doesn’t require expensive equipment or constant maintenance. It just takes a smart approach and a little attention to detail.
1. Control Moisture and Humidity
Keep your indoor humidity between 30% and 50%—you can use a hygrometer to measure it. A dehumidifier in basements or crawlspaces can work wonders.
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Use bathroom exhaust fans when showering
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Vent clothes dryers to the outside
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Fix plumbing leaks immediately
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Install proper gutters and downspouts to direct water away from the house
2. Use Mold-Resistant Drywall
In high-risk areas like basements, bathrooms, or kitchens, ask your contractor to use mold-resistant drywall (also known as green board or purple board). It’s designed with fiberglass mats instead of paper, which mold doesn’t like to eat.
3. Seal and Paint Properly
Using a mold-inhibiting primer and moisture-resistant paint can help create a barrier. Always make sure surfaces are completely dry before painting—trapping moisture under paint is one of the most common mistakes we see.
4. Check Your Insulation
In North Carolina, temperature swings can cause condensation inside the walls. Proper insulation prevents this by keeping warm, moist air from hitting cold surfaces.
Use closed-cell spray foam or a vapor barrier where appropriate, especially in basements or crawlspaces.
5. Maintain Proper Ventilation
Good airflow keeps moisture from building up. Make sure your attic, crawlspace, and bathrooms are properly ventilated. In some cases, adding a whole-house ventilation system can help balance indoor air pressure and humidity.
When to Call a Professional Drywaller
If you suspect mold or find damage to your drywall, it’s important to act fast—but not necessarily to tear into the wall yourself.
Here’s when it’s best to call a pro:
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You smell mold but can’t find the source – We can help locate hidden leaks or moisture issues with non-invasive tools.
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You’ve had a recent flood or water damage – Time is of the essence. Mold can start to grow in as little as 24-48 hours.
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You find visible mold on drywall – Drywall can’t be cleaned like tile. If it’s moldy, it needs to be removed, safely.
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You’re remodeling a bathroom or kitchen – This is the perfect time to upgrade to mold-resistant drywall and proper moisture control.
At Faircloth Drywall, we’ve been repairing, replacing, and installing drywall in homes across the Raleigh-Durham-Chapel Hill area for over 40 years. We know the signs to look for, the materials that last, and the tricks of the trade that keep mold from coming back.
The Bottom Line
Mold on drywall isn’t just ugly—it can damage your home’s structure and impact your family’s health. The key is moisture control, smart material choices, and prompt action when something feels “off.”
And remember: there’s no shame in asking for help. You don’t have to tear open walls or take on mold alone. A seasoned drywall expert can assess the situation, fix the issue at its root, and make your walls look brand new.
If you’re dealing with mold—or want to make sure you never do, get in touch with us at Faircloth Drywall. We’re here to help.