Can You Use Exterior Paint Inside Of Your House? Our Expert Explains

When you end up having extra exterior paints around your house, it’s natural for you to think about using them indoors. However, can you use exterior paint inside? Exterior paints are designed differently than interior paints, and using them on interior walls can be harmful. But what makes them any different from interior paints?  

Paints for exterior walls contain a significant amount of chemicals that protect outdoor walls against sunlight, rain, and snow. People who regularly come into contact with its toxic properties can suffer from its harmful effects. Apart from that, if you paint indoor walls with exterior paints, it can lead to hazardous fumes and unpleasant odors all over the house. 

Exterior paints can also cause unavoidable severe health issues. In addition, you may think it’s a good idea to mix indoor and outdoor paints. But this is also something that you might want to reconsider. In this article, I will try to cover everything you should know before using exterior paints indoors. So, keep on reading for a proper picture.  

The Difference Between Exterior and Interior Paint

Exterior paints are primarily designed to withstand harsh weather conditions. You would notice, it survives years without cracking or fading. The reason behind this is, exterior paints have additional elements such as strong resins, adhesions, and silicones. These chemicals ensure the paint lasts longer, and protect your house from external damage. 

Again, to protect the walls from mold, fungus and other microbial contamination exterior paints have mildewcides in them. It is a strong agent that protects the walls with an additional layer through which dirt and other elements cannot penetrate. So, as you can see, exterior paints have several strong chemicals in them which are poisonous.  

The paints used in interior settings are usually made less hazardous since they are used indoors. They have a small number of chemicals in them. Additionally, for keeping human health in mind, interior paints usually regulate the use of volatile organic compounds. Some companies also make waterproof paints, but that too will not last long. 

Read also  Fiberglass VS Aluminum Windows: Which Should You Get?

Due to their plastic properties, interior paints are easier to clean by whipping or scrubbing. However, constant cleaning would break its barrier and you’d end up fading the paints. Therefore, you shouldn’t clean them regularly unless it’s necessary. Additionally, these paints can withstand moderate heat between 60- and 90-degrees Fahrenheit. This is ideal for a home setting.

So exterior paint may seem perfect for indoor use, but you can see how many added chemicals they contain. Manufacturers, therefore, make exterior and interior paints differently for various reasons. Thus, people should trust the paints they created and apply them appropriately as per their usage. 

Why You Should Avoid Exterior Paints Indoors

Your house should be a safe place for you and your family. So, you should be careful when choosing a finish for your walls. Now that you know the differences between exterior and interior paints, I’m sure you know why using exterior paints is a bad idea.  

However, for your ease, here’s a list of reasons why you should not be painting your indoor walls with exterior paints. 

1. Flammability Risks 

One of the biggest drawbacks of exterior paints is their risk of fumes. Since they are oil-based paints, they can catch on fire easily. However, the likelihood is low. Even so, for safe living, it has to be taken into consideration. The paint’s high VOC content makes it near impossible to breathe when it’s painted indoors. 

Therefore, if you paint the interior walls with exterior paints, you are likely to have breathing difficulties. Nausea, nasal congestion, lightheadedness, and headaches are also some common complaints from users. People with a weak immune system can develop chronic diseases. These include nervous system damage and cancer, to name a few. 

Read also  What is the difference between exterior and interior paint

2. An Overpowering Odor

Exterior paints have a strong odor that can be overwhelming to people. Many people think indoor paints have smells too, so it shouldn’t be a big problem. However, the situation here is different. 

Interior paints’ smell lasts only 2-4 days. Whereas, for exterior paints it will stay for months. This can cause severe discomfort and harm to children and pregnant women in particular.

So, if you still choose to paint with exterior paints, make sure your house has great ventilation areas. Natural air should be able to circulate throughout the entire house for the smell to disappear faster. Also, open your windows while the fans are running so the smell can escape. Painting interior walls with exterior paint is not a good idea if there are no ventilation options.

3. Expenses 

The cost of exterior paints is higher than interior paints. It’s because they must contend with harsh climate conditions. High-quality paints use better elements, such as better pigments and superior resins. 

For extreme durability throughout the years 100% vinyl acrylic colors are used in water-based paints. Additionally, they protect against moisture and UV rays. 

On the other hand, interior paints have a better environmental record, making them the ideal choice for indoor decorating. They are pretty basic so their prices are also lower than exterior paints. So, if you want to protect your health while saving money on your next painting project, interior paints are your best option. 

Some Exceptions to Using Exterior Paint Indoors 

It is possible to use exterior paints at home, but only if the room is rarely used by people. For instance, you can paint your storage sheds or pool house with them. They are not used as much as bedrooms or living rooms. So, it can be comparatively safer to paint them with leftover exterior paints. However, do give the paint enough time to dry before you start using the sheds.

Read also  How Long Does It Take To Install Vinyl Plank Flooring? Answered!

Otherwise, the VOC would create excessive gas that can cause several complications. If possible, leave the doors and windows open until the paint is completely dry and there are no smells. Do not ever use exterior paints in the garage or where you keep your cars. It can cause explosions because these areas are naturally heated by the vehicles’ engines. 

It’s not a problem if you paint the inside of your house with exterior paint if you don’t plan on living there for a few months. The harmful effects stay only for 4-5 months in the summertime, and 7-8 months during winter. 

Can You Mix Exterior and Interior Paints?

You can, but you shouldn’t. You’ll not get the protection your house needs on the exterior. And using them in the interior won’t make them any less dangerous than using unmixed exterior paints. So, mixing them together and using them will serve no good purpose.  

However, if you still want to mix them, make sure the base for both paints is the same. Never mix oil-based paints with water-based ones, as different bases don’t work well together. 

You might end up having uneven and patchy colors on your wall. Paint that contains oil and water also usually separates after a certain period. In other words, it will not last for long. 


To conclude, you should not use exterior paints on the inside of your house. It can become very hazardous for you and your family. And don’t even think that mixing them with interior paints will lessen the issue. As I’ve explained, it will not make the paint magically safe. I hope this article has helped you regarding the confusion around whether or not can you use exterior paints inside. Thanks for reading, and wishing you all the best! Goodbye!