Can You Use Exterior Paint on Interior Walls?

Many homeowners wonder if exterior paint can be used on interior walls. Continue reading as we talk about the differences between exterior and interior paint and whether using exterior paint indoors is a good idea. Understanding these factors will help you make the best decision for your painting project.

Differences Between Exterior and Interior Paint

Exterior and interior paint have various differences that allow them to be suitable for their intended use. Here is a list of those differences:

Durability: Exterior paints are formulated to withstand harsh weather conditions, including rain, wind, and UV rays. Interior paints are designed for easier cleaning and to resist stains and scuffs from everyday activities.
Chemical Composition: Exterior paints contain more resins and additives to enhance durability and adhesion on various surfaces. Interior paints have fewer harsh chemicals, making them safer for indoor air quality.
Flexibility: Exterior paints are more flexible to cope with temperature changes and prevent cracking and peeling. Interior paints are less flexible but offer a smoother finish suitable for indoor environments.
Mold and Mildew Resistance: Exterior paints often include mildewcides to prevent mold and mildew growth due to outdoor moisture. Interior paints focus more on being washable and scrubbable without needing these extra additives.
Finish Options: Both types of paint come in various finishes, but interior paints offer a wider range of sheens, including matte, satin, and semi-gloss. Exterior paints typically focus on durability over aesthetic variety.
VOC Levels: Exterior paints usually have higher levels of volatile organic compounds (VOCs) because they are used outdoors where ventilation is not an issue. Interior paints have lower VOC levels to maintain indoor air quality.

Pros of Using Exterior Paint Indoors

Using exterior paint indoors may seem unconventional, but it does have some benefits. Here are the pros of using exterior paint on interior walls:

Durability: Exterior paint is designed to withstand harsh weather conditions, making it more durable and long-lasting indoors. This durability means it can resist scuffs, scratches, and everyday wear and tear better than some interior paints.
Moisture Resistance: Exterior paint is formulated to resist moisture and mildew, which is beneficial in areas with high humidity, like bathrooms and kitchens. It helps protect walls from mold and water damage.
UV Protection: Even though UV rays are less of a concern indoors, exterior paint’s UV protection can help maintain the color and finish of walls in sunlit rooms. This reduces fading and keeps the walls looking fresh longer.
Versatility: Using exterior paint indoors offers versatility, as it can adhere to various surfaces, including wood, metal, and masonry. This makes it a practical choice for different areas within the home.

Cons of Using Exterior Paint Indoors

While using exterior paint indoors has some benefits, there are also several drawbacks to consider. Here are the cons of using exterior paint on interior walls:

Higher VOC Levels: Exterior paints often contain higher levels of volatile organic compounds (VOCs), which can be harmful indoors. These chemicals can cause strong odors and may pose health risks in poorly ventilated areas.
Cost: Exterior paint is generally more expensive than interior paint. Using it indoors can increase your project costs without providing significant benefits for most indoor applications.
Finish and Texture: Exterior paints are designed for durability rather than smooth finishes. This can result in a rougher texture that may not be ideal for interior walls where a finer finish is preferred.
Harder to Clean: The tougher resins in exterior paint can make it more difficult to clean with standard household cleaners. This can be an inconvenience for routine maintenance.
Incompatibility: Exterior paint is not always compatible with interior surfaces and conditions. It might not adhere as well or could react differently under indoor lighting and temperature fluctuations.

Situations Where Exterior Paint Might Be Suitable Indoors

There are certain situations where using exterior paint indoors might be a practical choice. Below are several scenarios where it could be suitable:

High-Moisture Areas

In places like bathrooms and kitchens, where moisture levels are consistently high, exterior paint’s moisture-resistant properties can be beneficial. It helps prevent mold and mildew growth, ensuring the walls stay clean and dry.

Exterior paint’s durability also withstands the frequent cleaning and scrubbing required in these areas. This makes it a practical option for maintaining a fresh and hygienic appearance over time.

Basements

Basements often have higher humidity levels and are prone to dampness. Using exterior paint in this environment provides extra protection against moisture seepage and potential water damage.

The tough and resilient nature of exterior paint can also help in basements that experience temperature fluctuations. This ensures the paint remains intact and provides a long-lasting finish.

High-Traffic Areas

For high-traffic areas like hallways, mudrooms, and entryways, exterior paint’s durability offers added protection against scuffs and scratches. These areas see a lot of activity, and exterior paint can handle the wear and tear better than standard interior paint.

Using exterior paint in these spots means the walls will look good for longer, even with the constant use and contact they receive. This reduces the need for frequent touch-ups and repainting.

Utility Rooms and Garages

Utility rooms and garages are often exposed to harsher conditions, such as temperature changes and increased dirt and grime. Exterior paint’s robust formulation makes it well-suited for these environments.

Applying exterior paint in these areas ensures the walls can withstand the unique challenges they face, providing a durable and easy-to-clean surface. This keeps the spaces looking functional and well-maintained.

Safety Considerations

When using exterior paint indoors, it’s important to consider safety. Read below for the key safety considerations to keep in mind:

Ventilation: Ensure the area is well-ventilated. Open windows and use fans to circulate air and reduce the concentration of paint fumes.
Protective Gear: Wear protective gear such as gloves, goggles, and masks to avoid direct contact with the paint and to protect yourself from inhaling harmful fumes.
Label Instructions: Follow all instructions on the paint label carefully. This includes guidelines for application, drying times, and safety precautions specific to the product you are using.
Keep Away from Children and Pets: Make sure children and pets are kept out of the painting area. Paint fumes and chemicals can be harmful to them, so it’s best to ensure they are in a safe, separate space until the paint is dry.
Storage: Store paint and painting supplies in a cool, dry place away from direct sunlight and out of reach of children and pets. Proper storage helps prevent accidents and maintains the quality of the paint.

Alternatives to Exterior Paint for Interior Use

If you’re looking for alternatives to using exterior paint indoors, there are several options designed specifically for interior use. These alternatives offer the durability and finish you need for various indoor spaces. Here are some options:

Interior Latex Paint: This paint is water-based and easy to clean. It dries quickly and emits fewer fumes, making it safer for indoor use. It is ideal for walls and ceilings in living areas, bedrooms, and other common spaces.
Acrylic Paint: Known for its durability and versatility, acrylic paint works well on different surfaces. It is resistant to moisture and can be a good option for kitchens and bathrooms.
Enamel Paint: Enamel paint provides a hard, glossy finish that is durable and easy to clean. It is suitable for trim, doors, and high-traffic areas where a tough surface is needed.
Mold-Resistant Paint: Specifically formulated to resist mold and mildew, this paint is perfect for bathrooms, basements, and other damp areas. It helps maintain a clean and healthy environment.
Stain-Resistant Paint: Ideal for kitchens and children’s rooms, stain-resistant paint makes it easy to wipe away spills and stains. It offers long-lasting protection and keeps your walls looking fresh.
Zero-VOC Paint: For those concerned about indoor air quality, zero-VOC paint is an excellent choice. It emits no harmful fumes, making it a healthier option for you and your family.

Conclusion

Using exterior paint on interior walls has pros and cons. While it offers durability and moisture resistance, it also has higher VOC levels and a rougher finish. For most indoor projects, it’s best to choose paints specifically designed for interior use.

If you need interior painting services, contact Custom Painting, Inc. Call us at 925-294-8062 or fill out a Contact Form to know more.