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.
Can You Use Exterior Paint on Indoor Walls?
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:
Let’s look at each of these a little closer.
1. Exterior Paint isn’t Safe for Indoor Use
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.
2. Exterior Paint Doesn’t Have a Great Indoor Finish
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.
3. Exterior Paint is Usually More Expensive
Finally, if you were considering purchasing outdoor paint for interior walls, you will probably pay more. The increase in price is related to the compounds we previously mentioned that make exterior paint more durable.
You’re better off purchasing quality interior paints, than spending more money on exterior paint and also dealing with the safety issues.
Here are several links to both interior and exterior paints.
These are just examples. Please note: there is expensive interior paint and inexpensive exterior paint. However, assuming equal quality, you are likely to pay slightly more for the exterior paint.
What Should I Do If I Used Exterior Paint Inside?
If you are reading this information post-painting experience, then you are likely wondering what you should do. Here are several steps to take right now:
- Check you and your families physical well-being
- Consider hiring a professional to paint over exterior paint with safer interior paint
Check Your Family For Reactions to Exterior Paint
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
After you’ve taken action to remove anyone negatively affected, you should try your best to allow fresh air to flow into the problematic room. Open a window, use a fan to push air outside, allow those harmful fumes from the exterior paint to flow out of your home.
Note that the fumes from these exterior paints are usually worse in warm and humid weather. People have reported a foul odor that they were unable to identify.
Consider Hiring a Professional to Remove Exterior Paint
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.
VOCs – Volatile Organic Compounds in Exterior Paint
VOC is a broad term for chemicals that readily turn into a gas. This ability to sort of jump out of the compound that they are in is what makes them Volatile.
The base of these chemicals are organic elements, like carbon. These molecules are what build the products, like paint thinner, or industrial adhesives.
This term simply means that they are composed of more than one substance.
There are many different types of VOCs. Here is a list of a few:
These compounds have important uses within the paint, but their volatile nature means that they can become harmful fumes.
Here are some things you can do to protect yourself from VOCs.
- Follow safety guidelines on the paint can
- Buy paints with lower levels of VOCs
- Don’t use outdoor paint inside
With proper ventilation, you shouldn’t have major issues with VOCs in exterior paint – as long as it’s used where it’s intended. Also, be sure to properly dispose of all extra paint. Do not store opened paint cans in your living areas.
If you have old paint, and wonder if it is still good, read here to find out.
Final Words About Using Exterior Paint Indoors
Though it may be tempting, we advise against using exterior paint indoors. You don’t want to take a chance with the potential risks. Here is a quick review:
- Exterior paint has higher levels of VOCs
- VOCs create fumes that are unsafe to inhale
- Exterior paint is more expensive
- Indoor paint will have a better finish
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.
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