Preventing Mold Under Paint: What You Need To Know

Painting over mould might seem like a quick fix, but it's important to remember that it only hides the problem. Mould can cause serious health issues, including respiratory tract infections, exacerbating asthma, and irritating allergies. To prevent mould from growing under paint, it is crucial to address the root cause of the mould, such as fixing a leaky pipe or adding a dehumidifier to the room. Once the source of moisture has been corrected, the affected area must be thoroughly cleaned and dried before applying a coat of primer and paint. While some paints contain mould inhibitors, it is recommended to use a mould-resistant paint specifically designed for high-humidity areas.

How to Ensure Mold Isn't Under the Paint

Address the root cause of the mould

Painting over mould may seem like a quick and easy fix, but it is important to address the root cause to prevent it from recurring. Mould can cause serious health issues, including respiratory tract infections, exacerbating asthma, and irritating allergies, so it is crucial to properly remove and treat mould before painting. Here are some ways to address the root cause of mould:

Identify the Source of Moisture

The presence of mould indicates persistent humidity or moisture in the environment. Identify and address the specific cause, such as leaks, condensation, or inadequate ventilation. Fix any leaky pipes, address ventilation issues, and use bathroom fans or dehumidifiers to reduce moisture levels.

Clean and Dry the Surface

Before painting, ensure that the affected surface is thoroughly cleaned and dried. Use soap, mild detergent, or sugar soap to scrub away mould residue and stains. Then, rinse the area with clean water and ensure it is completely dry. Open windows, use fans, or run a dehumidifier to accelerate the drying process.

Use Mould-Killing Products

Apply a mould-killing chemical or a natural remedy, such as vinegar, to eliminate mould spores. You can find mould-killing products at your local hardware store or opt for natural alternatives like vinegar or borax solutions.

Apply a Mould-Resistant Primer

Once the surface is clean and dry, apply a mould-resistant primer or undercoat to prevent future mould growth and block stains. Look for primers with mould inhibitors, such as those from Zinsser or Dulux. Earthpaint also offers a product called Lime Primer, which is specifically designed to prevent mould growth.

Choose the Right Paint

Select a mould-resistant paint that is suitable for high-humidity areas. Avoid oil-based paints, as they may contain ingredients that mould can feed on. Instead, opt for high-quality interior latex paints with additives to help prevent mould regrowth.

Remember, addressing the root cause of mould is crucial to ensure its long-term prevention. By following these steps, you can effectively treat mould and create a safe and healthy environment before applying paint.

Clean and dry the surface

To ensure that mould doesn't return under a new coat of paint, it is important to clean and dry the surface thoroughly. Here is a step-by-step guide to doing this:

Firstly, scrub away any mould residue with soap and water or a mild detergent. You can also use a sugar soap to thoroughly clean the surface. Next, wipe down the area with clean water to remove any remaining soap residue. It is important to ensure that all mould stains are removed, as they can show through the new paint.

Once the surface is clean, it is crucial to dry it completely. Mould thrives in moisture, so leaving any damp patches can allow mould to regrow. Open windows and use fans or dehumidifiers to speed up the drying process. If the area stays damp, address any leaks, condensation, or ventilation problems before continuing.

Before painting, it is also important to address the underlying cause of the mould. This could include adding a dehumidifier to the room, fixing leaky pipes, or improving ventilation. By addressing the root cause, you can help prevent mould from returning.

Once the surface is clean, dry, and mould-free, you can be confident that your new coat of paint will last longer and be less likely to be affected by mould.

Use mould-killing products

Painting over mould may seem like a quick fix, but it is important to remember that it only hides the problem and does not address the root cause. To effectively deal with mould and prevent it from growing under the paint, it is crucial to use mould-killing products and take the necessary steps to ensure proper removal.

One recommended approach is to use a natural, organic solution. Start by dipping a roller in vinegar (rice wine or apple cider) and applying it to the affected area. This step helps to eliminate mould spores. Following this, use a special Lime Paint over a quartz-stone primer. The Lime Paint increases the alkalinity levels in the air, creating an environment where mould cannot thrive.

Alternatively, you can opt for mould-killing chemicals available at your local hardware store. After treating the mould, it is essential to sand down the surface and apply a stain-blocking primer or undercoat, such as those offered by Zinsser or Dulux. These primers and undercoats are designed to prevent future mould growth and block stains from showing through the paint.

If you're looking for a specific anti-mould paint, you can try Concrobium fungicide spray, an all-natural product that kills mould and prevents new mould growth. Once the Concrobium spray has dried, you can apply a mould and mildew-resistant primer, such as Zinnser Bulls Eye 1-2-3 Waterbase Primer. For areas with significant water stains, a stronger product like Zinnser Guardz is recommended.

While some sources suggest using a bleach and water mixture to kill mould, it is important to note that bleach does not kill mould spores and can even cause them to migrate. Additionally, bleach releases carcinogens when it comes into contact with mould. Therefore, it is advisable to opt for natural alternatives or specialised mould-killing products.

Apply a coat of primer

Painting over mould may seem like a quick fix, but it only hides the problem and can lead to bubbling, peeling, and discolouration as the mould continues to spread. To effectively deal with mould and ensure it doesn't come back, you must address the underlying cause, such as fixing a leaky pipe or adding a dehumidifier to the room. Once the source of moisture has been corrected, you can start the process of applying a coat of primer and paint.

Before applying primer, it's crucial to properly clean and dry the surface. Use soap and water or a mild detergent to scrub away any remaining mould stains, then wipe down the area with clean water. Ensure the surface is completely dry by opening windows, running fans, or using a dehumidifier. This step is essential to prevent trapping moisture beneath the paint, which can create an ideal environment for mould to thrive.

When choosing a primer, opt for a high-quality, mould-resistant product. While primers won't kill mould, they can help prevent future growth and block stains from showing through. Look for primers with mould inhibitors, such as those from reputable brands like Zinsser or Dulux. Earthpaint also offers a product called Lime Primer, which can be applied directly to mould and guarantees that mould will not grow on it.

Once the surface is clean and dry, you can start applying the primer. Use a roller or a brush to evenly coat the affected area. Follow the product instructions for drying time and ventilation requirements. It's important to work in a well-ventilated area when applying primer and paint to ensure your safety and comfort.

After the primer has dried, you can proceed to select the right type of paint and finish to further inhibit mould growth. Choose a mould-resistant paint specifically designed for high-humidity areas. Avoid oil-based paints, as some contain ingredients that mould can feed on. Instead, opt for high-quality interior latex paints with additives to prevent mould regrowth.

Choose the right paint

Painting over mould may seem like a quick fix, but it is important to remember that it does not address the root cause. The mould will continue to spread under the paint, causing bubbling, peeling, and discolouration. Therefore, it is crucial to properly remove mould and ensure the surface is clean and dry before painting.

To prevent mould from growing under the paint, it is essential to choose the right type of paint and primer. Here are some important considerations:

Type of Paint

Select a paint that is specifically designed to inhibit mould growth. Some paints contain additives that help prevent mould regrowth. Look for high-quality interior latex paints, as they often include mould inhibitors. Avoid oil-based paints, as some contain ingredients that mould can feed on.

Mould-Resistant Primer

Before applying the paint, use a mould-resistant primer or undercoat. While primers won't kill mould, they help prevent future growth and block stains from showing through. Look for products like Zinsser Bulls Eye 1-2-3 Waterbase Primer or Earthpaint's Lime Primer, which are specifically designed to inhibit mould growth.

Surface Preparation

Ensure that the surface is properly cleaned and dried before applying the primer and paint. Use soap and water or a mild detergent to remove any mould stains and residue. Then, wipe down the area with clean water. Make sure the surface is completely dry to prevent trapping moisture beneath the paint, as mould thrives in moisture.

Address Moisture Issues

If mould was present due to persistent humidity or leaks, address the underlying issue. Improve ventilation, run a dehumidifier, or fix any leaks to keep moisture levels under control. This will help create an environment less conducive to mould growth.

Natural Remedies

If you prefer natural remedies, some options include using vinegar (rice wine or apple cider) or a Borax and water solution to clean the surface before painting. These natural alternatives can effectively eliminate mould and prevent regrowth.

Remember, it is crucial to address the root cause of mould and properly prepare the surface before choosing the right paint and primer to ensure effective mould prevention and a long-lasting paint job.

Frequently asked questions