Can You Use Exterior Paint Indoors?

Exterior paint is known to be both strong and durable. But, is it appropriate for indoor use? It may seem like a great idea to use exterior paint on interior walls; however, this option has serious downfalls. One has to beware of the dangers of exterior paint when it’s used indoors.

You can use exterior paint indoors, but it is not ideal because of the emissions that it produces. Exterior paints are generally stronger and contain volatile organic compounds that are not ideal for indoor use. Interior paint is often cheaper than exterior paint, so it is better to use inside than exterior paint.

If you’d like to finish up a bucket of exterior paint, consider giving your shed another coat or touching up the garage. However, we cannot advise that you use exterior paint indoors. We will explore this question more bellow.

While it has been done before, we don’t advise it. Upon first consideration, it may seem better to use exterior paints inside because of their ability to withstand significant outdoor challenges. This is especially true in areas of the home that have a tendency to experience moisture or humidity problems, like the bathroom. Knowing that interior walls can encounter similar issues as exterior surfaces, one may think to turn to exterior paints as a solution.

However, exterior paint can cause far more harm than good when it is used inside. Not only is it unsafe, but exterior paint probably won’t look as good in your living spaces as standard indoor paint. Here are several reasons to skip painting your indoor walls with exterior paint:

The primary reason that exterior paint is so unsafe for indoor use is that it contains a much higher number of VOCs (Volatile Organic Compounds, we will explain these in more depth later). These chemicals can cause eye, nose, and throat irritation. You don’t want your children breathing in large amounts of VOCs. It’s not worth the risk.

The harmful paint fumes that are produced from such a high concentration of VOCs can permeate your living spaces for six months or longer. These fumes are not only bad for the health of you and your family, they are also considered bad for the environment. Therefore, it is best to leave the exterior paint outside where it has space to breathe.

Furthermore, exterior paints typically contain fungicides and mildewcides. These ingredients are important to prevent structural damage to your home’s exterior; however, these components are also likely to cause allergic reactions. These problems are more intense if there is someone in your household who struggles with asthma or other respiratory-related ailments.

The trouble with indoor paints is usually a matter of going cheap. Flaking, peeling, and multiple coats are all a telltale sign of cheap paint. Take the time to research several quality indoor paints, and then try out a few samples.

What you’ll find is that quality indoor paints have a better, smoother finish than exterior paints. Not only that, but if you spend a little more money, your indoor paint will hold up very well.

Unlike exterior paints, interior coatings are specially designed to hold up to the level of traffic that indoor environments experience on a daily basis. Repeated bumps and scrapes against woodworking and walls are cushioned by the proper indoor paint formulation. The resins and additives in interior coatings offer the ideal finish that can also withstand the frequent dusting and scrubbing that interior walls necessitate.

Does anyone seem to be reacting poorly? Cough or difficulty breathing should raise concern. Also, some people have other symptoms, like nausea or headache. We are not a medical authority. However, common sense would advise you to take caution and remove the person with the symptoms from the environment.

VOCs found in exterior paints are known to cause what is called “sick building syndrome.” Symptoms of this disorder include nausea, lightheadedness, and headaches.

Here is an article from poison control that explains more about potential paint poisoning: Poison.org

This depends on how comfortable you are with the situation. However, if you are having issues, you shouldn’t let it slide. It may be time to hire a professional to remove or neutralize the exterior paint and then apply a safe coat of interior grade paint.

If you decide to battle this issue on your own, consider using a highly efficient mask to lower your exposure to harmful fumes. If you do this and establish ventilation, you are taking appropriate steps to ensure safety.

Most people find that fumes from exterior paints are unbearable in interior dwellings. However, this problem is most often fixed by painting again with the correct interior paint. Prior to painting, as much of the old paint should be removed as possible. This can be done by sanding or scraping the surface. Then, wash the surface, let it dry, and apply a primer before you continue with painting.

See this article for additional paint removal techniques.

Perhaps you know someone who has used exterior paint indoors and had no issues. Use caution when comparing someone else’s experience to your own. It could be the case that they had no issues; however, there are probably other factors to consider.

They may have more ventilation in their home. Or, they may have used the paint in a low traffic area, and aren’t often exposed to the fumes. Either way, people will react in different ways to exterior paint fumes. It’s probably not worth the risk.

Regardless, if you keep safety in the front of your mind, and take your time to do the job well, you won’t go wrong.