In the world of do-it-yourself painting projects, the issue of painting over mold is one that deserves careful consideration and attention.
Can you paint over mold? Yes, but you should do so only with mold-resistant paint. These specially formulated paints include antimicrobial agents that repel bacteria. That protection can last for several years. However, the only definitive way to fully control mold and safely paint over it is to find and eliminate its source.
Today, I’m going over how to safely and effectively paint over mold. Read on!
How to Paint Directly Over Mold
If your mold problem isn’t widespread, such as occupying only part of the wall at your bathroom vanity or your exterior soffit, painting over mold is straightforward.
1. Scrape Away the Mold
2. Clean the Cleared Area
Once you’ve removed the mold, you’ll need to clean the area. Make a cleaning solution by adding 1 cup of bleach to 1 gallon of water. Transfer some of the solution into a spray bottle, wet down the cleared area, and work the solution in with a stiff brush.
Allow the area to dry before proceeding. To ensure that the treated area is completely dry before priming and painting, operate a fan or dehumidifier near the treated area.
3. Apply Mold-Killing Primer and Mold-Resistant Paint
In response to increasing consumer demand in recent years, the number of available options for mold-killing primers and mold-resistant paint has expanded. In fact, mold-resistant paint was originally available in just white and gray but can now be found in an array of colors.
Among the best mold-killing primer options is Rust-Oleum Zinsser 276087. Rust-Oleum Zinsser also offers top-quality mold-resistant paint. If you can’t get a mold-resistant paint in your preferred color, don’t worry. You can simply apply regular paint on top of your mold-resistant paint.
There aren’t any special tricks for applying mold-killing primer or mold-resistant paint when painting over mold. Both can be either brushed or rolled onto the surface. Be sure that your mold-killing primer is thoroughly dry before applying paint. Routinely, it will take an hour for mold-killing primer to dry enough for painting.
Also, you should plan on priming and painting the entire wall along which you are addressing your mold issue to ensure uniform color.
More Tips for Painting After Mold Removal
In choosing the paint you’ll use to cover the area or areas where you’ve addressed mold problems, you’ll face two issues.
One of those issues is whether you should use oil-based, latex or acrylic paint for painting over mold. A second issue is the paint’s sheen, an indication of its reflectivity. A paint’s sheen can affect its durability and how easy, or difficult, it may be to clean.
Oil-Based, Latex and Acrylic Paint
Technically, latex and acrylic paints, which both are water-based, can be used in areas where moisture might be an issue. But just as you might suspect, an oil-based paint likely will be your best choice when repainting an area where mold has been a problem.
In addition to not being susceptible to moisture issues like water-based paint, oil-based paint is more durable. Also, oil-based paint will cover a surface with fewer coats than water-based paint. However oil-based paint will release potentially hazardous volatile compounds during the painting process.
If you want to know whether the paint currently used in the area where you’re dealing with mold is oil-based or water-based, there’s a simple test. Simply rub a small area with denatured alcohol. If any paint comes off or is made tacky to the touch, it’s a water-based paint.
There are five paint sheens from which to choose in addressing any need for painting over mold. In ascending order of shine, those sheens are: Flat (also called matte), eggshell, satin, semi-gloss, and gloss. As a general rule, satin and semi-gloss sheens are the best choices for areas where moisture might be a problem.
Each of those sheens offers hard and moisture-resistant finishes. As an added bonus, they are very scrubbable and washable. Choosing one of those sheens will help ensure that painting over mold won’t ever again be much of an issue for you.
Addressing Mold on Interior Surfaces
When dealing with painting over mold inside your home, the old saying that an ounce of prevention is worth a pound of cure is certainly applicable. If you want to keep painting over mold from becoming a problem in your home, there are a number of preventative steps to take.
- Pick up wet towels and clothes immediately and get them into the washer or dryer.
- Make sure your bathroom exhaust fan is running while showering, and wipe down the floor and walls when your shower is over.
- Regularly check the condensation pan and drain lines under your air conditioner to be sure they’re functioning properly. Also, make sure that the ductwork for your air conditioning system is tightly sealed.
- If your yard slopes toward your home, regrade your lot so that water is carried away from the structure.
If your painting over mold problem is confined to a manageable section of your home’s drywall, you can consider simply cutting out and replacing the problematic area. DIY Painting Tips has information on drywall repair to help you through this process.
Once your painting over mold problem has been located and addressed as completely as possible, you might want to consider encapsulation of any remaining trouble spots. Mold sealants are available at many home improvement stores and can be applied by DIYers.
If you do decide to encapsulate mold as part of a DIY project for painting over mold, be sure to wear protective gear. That gear should include at least an N-95 respirator and disposable gloves.
Addressing Mold on Exterior Surfaces
Just as with painting over mold issues in your home’s interior, preventing it from forming on exterior surfaces in the first place is the best strategy.
Keep Gutters Clean
One thing you can do to keep mold from forming on the exterior of your home is to keep your gutters cleaned out. Gutters full of leaves, twigs, and other debris will hold moisture close to the side of your home’s exterior, providing a breeding ground for mold.
Shrubs, flowers, and other plants can add a truly decorative touch to your home’s exterior. But if they are allowed to grow unchecked, they can trap moisture against the side of the structure. And, as you’ve learned, that’s a recipe for mold formation and the subsequent issue of painting over mold.
The solution is simple. Keep shrubs and other vegetation trimmed some distance away from exterior walls. That way, you shouldn’t have to worry about painting over mold.
Using Trisodium Phosphate
Just like with interior surfaces, there are mold-resistant primers and paints that you can use on the exterior of your home. But before you apply them, you should thoroughly clean the affected areas with trisodium phosphate (TSP) as part of your efforts in painting over mold.
Available at home improvement stores, TSP can be used in pressure washers to make quick work of mold removal. Adding a bit of bleach to the TSP can produce even better results than TSP alone for mold removal.
You will definitely need to wear protective gear while using TSP, even if you’re simply brushing it on as opposed to using a pressure washer. Also, whether you’re spraying or brushing TSP, keep children and pets out of the area where you’re working.
Painting Over Mold Frequently Asked Questions
Now that you’ve learned something about painting over mold, some additional questions may have occurred to you. Read on for answers to some of the most frequent queries about dealing with mold on or under painted surfaces.
What are the adverse health effects of mold?
Molds are fungi that produce spores that can become airborne. Once mold spores land on a moist surface, they begin to grow. As they grow, spores — along with other components of mold — can become dislodged from the surface and enter the air.
When they are breathed in, the spores and other mold particles will irritate the nose, throat, and lungs. They can be particularly irritating to people with asthma, lung problems, or other breathing conditions. In some people, mold can trigger bronchitis, an inflammation of the airways to the lungs.
More broadly, the presence of mold can trigger anything from nausea to headaches to fever. Other health problems from mold can include wheezing, fatigue, and nausea. People with compromised immune systems are particularly susceptible to adverse health effects from mold.
What is an acceptable level of moisture in a home?
Given that moisture is a breeding ground for mold, homeowners should be aware of the humidity level in their residences. Monitoring humidity is as simple as purchasing a hygrometer for home installation.
The humidity in your home will depend on the area in which you live. Generally speaking, your indoor humidity should be between 30% and 50%. Anything consistently over 50% humidity can be too moist, potentially prompting mold growth.
What can be done to reduce the potential for mold development in a home?
As you’ve probably guessed, controlling mold in your home is all about controlling moisture levels. Read on for some moisture-reducing tips.
- Be sure moisture-producing appliances such as clothes dryers and stoves are vented to the outside.
- Install an air conditioner and/or dehumidifier. However, you should recognize that they produce moisture as they work. Be sure moisture from air conditioners and dehumidifiers is properly drained or otherwise removed from the interior of your home.
- Open a window or run an exhaust fan while cooking, showering, or washing dishes. This is particularly important if your home is designed to be highly energy-efficient, in which case it is tightly sealed. That seal can impede ventilation and potentially encourage mold formation.
If you learn one lesson about painting over mold, be sure that it’s to find and address whatever led to mold formation in the first place. Addressing the underlying cause of a mold issue is the surest way to avoid future problems with painting over mold.
As far as other painting projects are concerned, you’ll find all kinds of help through DIY Painting Tips. From helping you select the best supplies for your project to show you how to paint a room properly, DIY Painting Tips is an unbeatable resource.
I started painting in 2001 and have seen just about everything in my painting career. I started in production and commercial painting, then moved over to new construction and remodeling during the boom of the early 2000s. Post 2010, I niched down into residential painting where I have done everything from exteriors, decks, interiors, furniture and more. Over the last few years, I’ve had a focus on kitchen cabinets.
I started the DIY Painting Tips blog in 2015 to start sharing everything I’ve learned over the years and help all the people who’d rather tackle their painting projects themselves.
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