8 Things to Know Before You Paint Over Mold

What You Need to Know

• Painting over mold without first treating the mold can make the paint bubble and peel.
• Homeowners will first want to remove the mold and then paint over it with a mold-resistant primer.
• Large areas of mold and mold on wooden surfaces are best treated by a mold remediation professional.

Q: I just discovered mold on the walls in my bedroom. Is there an easy way to get rid of it? What happens if you paint over mold?

A: Painting over mold may cover up the dark patches where the mold is growing, but it will not eliminate the problem. Mold is a fungus that will thrive where there’s enough moisture to encourage its growth. It’s physically possible to paint over mold, but it will always reappear without proper remediation. Using mold-resistant paint works to prevent mold growth, but it won’t kill it once it’s started to grow. Mold can cause severe respiratory issues for people and pets. Before taking steps to clean and kill the mold, identify where the excess moisture is coming from and take steps to treat it. Contact a professional to remediate the mold issue if it’s growing in a continuously wet area or if the mold covers a large area.

Painting over mold will not destroy mold or prevent it from growing.

Painting over mold may seem like an easy solution to how to get rid of mold. It’s a quick fix to cover up the ugly stains, but it won’t solve the issue at the source. Paige NeJame, the owner of South Shore CertaPro Painters, explains, “Paint is porous to some degree, and mold can continue to grow underneath the paint coating.” While painting may seem to mask the problem for a short time, as the mold continues to grow it will cause the paint to chip, peel, and bubble. “Many people try to do this, especially if they won’t be living in the house; for example, they are selling and trying to cover up the mold. In a short time, the mold could reappear,” says NeJame. Homeowners may think that by painting over mold they are saving money on the cost of mold remediation, but in reality, they will simply pass the cost and the potential health consequences of the mold issue to an unsuspecting buyer.

Mold can be a health risk for both two- and four-legged family members.

Mold is a fungus that loves moisture. Mold growth commonly appears as gray, brown, or black mold splotches, but it can also be white, green, orange, or pink. Mold spreads quickly with spores that travel through the air. When humans or animals inhale those spores, they can cause serious respiratory issues. According to the Centers for Disease Control and Prevention (CDC), mold can cause many different health issues when it produces allergens. Some symptoms of mold exposure are a stuffy nose, sore throat, skin rash, wheezing, coughing, and burning eyes. Those who are immunocompromised or have a mold allergy or chronic lung disease are at even greater risk when exposed to mold. It’s especially worthwhile to identify black mold and other toxic varieties that pose negative effects even for healthy people.

Homeowners who see unsightly splotches on their walls may wonder, “Can you paint over black mold?” But in order to maintain a safe and healthy home, it’s essential to understand why mold is growing and get rid of it as quickly as possible rather than using paint for mold to mask it without addressing the underlying issue.

Mold-resistant paint and primers only work proactively.

Some paints and primers advertise that they are mold-resistant or antifungal. This can be misleading and cause homeowners to wonder, “Does painting over mold kill it?” Unfortunately, there is no mold-killing paint on the market that will stop mold that is already active. Instead, these paints only prevent mold growth after the mold has been successfully cleaned and destroyed to avoid regrowth. Once the mold has been completely removed by a professional, it’s a good idea to also apply a diluted bleach solution to the mold on the walls before painting to ensure any remaining spores have been eliminated. Then, mold-resistant paints can be applied as an additional line of defense. Anti-mold paint works by using an antimicrobial formula to create a barrier against mold spores and is especially useful in high-moisture areas like bathrooms, kitchens, or laundry rooms.

Painting over mold without first removing it will cause the paint to bubble and peel.

Mold is not just a stain; it is a living organism that will grow and thrive under the right conditions. Painting over mold will not prevent it from growing, especially if the damp conditions that led to mold growth in the first place are not remedied. If someone has just moved into a new home and has reason to suspect that the previous owner attempted to conceal mold growth, here’s how to tell if mold has been painted over:

• White or pastel walls may show dark discoloration, the paint may be bubbling or chipping in some places, and the surface of the wall may be bowed and misshapen.
• Mildew might show up as a light-colored growth on the surface of the walls or ceiling.
• Another telltale sign is the smell of mold lurking just out of sight. It may be worth the cost to have a mold inspection (or to purchase a mold test kit) to confirm whether or not mold is actually present.

Moldy wooden surfaces should be treated by a professional before painting to prevent the spread of mold spores.

Wood is an extremely porous material, so it can be especially challenging to remove mold from wooden surfaces. Traditional methods of mold removal like scrubbing with bleach may not be effective enough to completely eliminate the growth. Professionals will often sand mold-affected wood to reach spores underneath the surface. It’s not recommended for homeowners to do this themselves as it releases spores into the air that are potentially toxic. Professionals know exactly how to remove mold from wood safely and are equipped with gear that protects the home and themselves from mold exposure. They may also use a method called encapsulation as a last resort if the materials cannot be remediated or replaced. It’s important to note that encapsulation only seals away mold and prevents it from rising to the surface rather than completely eliminating it.

Remove the mold before painting, and ensure the surface is clean and dry.

When it’s time to treat the mold, homeowners or professionals will need to wear protective equipment such as a respirator mask, gloves, and eye protection. Some people prefer to use a mixture of bleach and water to spray on the mold to kill it. This works on the surface, but it doesn’t kill mold growing deep in drywall or wood. Vinegar penetrates deeper than bleach, so it’s a more effective mold killer. Spraying vinegar on mold and saturating the area will treat the root of the issue. Remember never to mix bleach and vinegar since it creates a toxic gas. Sometimes fungicide products can also be an effective solution. If the mold patch is extensive or recurring, homeowners are advised to contact a mold remediation professional. EPA recommendations state that growth exceeding 10 square feet or that is caused by contaminated water or sewage should be dealt with professionally. It’s also a good idea to leave the job to a pro if anyone in the household suffers from allergies, asthma, or a compromised immune system.

Once the mold is removed, use moisture-resistant primer or paint, especially in areas like the bathroom.

After the mold has been removed, it’s time to choose a high-quality moisture-resistant or mold-resistant primer. These primers are not mold killers, but they will prevent mold growth in the future and prevent any stains from showing through. After applying the primer, paint the area with two coats of semi-gloss or satin paint that repels water. “Most good-quality exterior-grade and some interior latex paints have a mold inhibitor in the product,” explains NeJame. “Do not use an oil paint as [it] sometimes has an ingredient on which the mold feeds. In potentially humid areas like basements and bathrooms, first clean with mold-killing detergent like Fiberlock Shockwave Cleaner and then use a bathroom paint or any paint labeled ‘mold-inhibiting paint,’” she recommends. It’s also important to consider the conditions that caused mold to grow in the first place. Usually, humidity and dampness are the biggest culprits. NeJame notes, “Since mold causes health issues, after painting it’s important that a good bathroom fan and/or dehumidifier run to help prevent mold from growing—especially in bathrooms and basements.” For the best results, the cost to paint a room by professional painters can be worth paying since the pros likely have experience in damp or mold-prone homes.

Use mold-resistant paint in shady outdoor areas to proactively stop mold growth.

While mold is most often an indoor consideration for homeowners, it can also grow on the exterior of the home. Parts of the house that are routinely exposed to water but are heavily shaded are especially vulnerable. Without access to sunlight, these spots stay damp and dark, which is an ideal climate for mold. It’s important to identify these parts of the home and treat them accordingly. If there is already mold growth, NeJame first recommends cleaning the area with a good mold remover, “On exteriors, we use Moldex or Jomax mold-killing detergent. Bleach alone will not be enough,” she says. Once homeowners are confident that the mold has been cleared, NeJame suggests protecting the area from future growth with mold-resistant paint: “In shady areas where mold tends to grow, a mold-resistant paint will inhibit the growth longer. Again, most good-quality exterior latex paints will contain this mold resistance.” Taking these steps will make mold growth less likely, but it may also be wise to consider trimming any trees and shrubs that block these areas from the sun. Homeowners who feel overwhelmed by the mold in their home, or those who have a pre-existing respiratory or immune issue, are advised to call a professional with the experience and knowledge to remove and clean mold.