Can I Use Exterior Paint Inside? (The Differences And Risks)

So, you’re ready to give your room a fresh coat of paint. But you’re not sure if it’s okay to use exterior paint inside, right? Well, before you make a decision on this, it’s crucial to understand the differences between exterior and interior paint, plus the risks involved.

While you can technically use exterior paint inside, it’s not recommended due to its high VOC compounds and odor. Interior paint is specifically formulated for indoor use, providing a safer and more suitable option for your home.

I would personally recommend that you avoid using external paint in the main rooms of a house, and especially in bedrooms. If you really want to use it inside, I would advise that you only use external paint in well ventilated rooms (for example, well ventilated garage rooms or workshops.)

Advantages Of Using Exterior Paints Inside

Using external paint inside does have it’s advantages though.

• The first one is the fact that this type of paint tends to be more resistant to smudges and abrasives.
• It also tends to last longer and become less dull as time goes on when compared to normal paint.

Now, let’s take a closer look at the differences between both type of paints.

The Differences Between Exterior Paints and Interior Paints

VOC Factor:	Exterior Paint:	Interior Paint:
Durability	High; withstands outdoor elements	Moderate; resists indoor wear and tear
VOC	Higher content	Lower content
Odor	Strong; lingers for a longer time	Mild; dissipates quickly
Resistance	UV rays, temperature changes, moisture	Abrasion, stains, scrubbing
Finish Options	Limited; usually semi-gloss or high-gloss	Varied; matte, eggshell, satin, semi-gloss, high-gloss
Dry Time	Slower; affected by outdoor conditions	Faster; consistent indoor conditions
Cost	Higher; due to added durability and protective features	Lower; less expensive materials and fewer additives
Ideal Use	Outdoor surfaces and structures	Indoor walls, ceilings, and trim

As I mentioned above exterior paint is designed specifically to last and withstand the elements of the outdoors.

For example, latex exterior paints are formulated specifically using flexible acrylic resins that are designed to either expand or contract with the blistering hot days or the days where temperatures reach well below freezing.

Interior paints are different. They take more of a beating from human touch, bumps and even splashing water such as near a kitchen sink and coated on the walls of your bathrooms.

Interior paints don’t need the same ability to expand and contract, so they are formulated in a different manner.

Interior paints are formulated with resins that allow the paint to produce a smooth finish. This finish is capable of holding up against dust, water and regular cleanings such as wiping down a wall or even scrubbing the wall.

Additionally, interior paint is designed to minimize any spray or splatter using additives that make it much cleaner and more manageable to apply with a brush or roller.

Exterior Paint Is Formulated Differently

I get it. You might want to use the have color you love or accidentally already purchased exterior paint for an interior job.

Exterior paints are typically designed to take a beating from all of the harsh elements of the outdoors.

So if you’ve got some leftover exterior paint, you might think: “Why not use it for inside? It’s just paint, right?”

It’s easier to think exterior paints would work great indoors.

But something that is often overlooked is the fact that exterior paint is made with different formulations.

You may have the paint on hand to get the job done now but is it worth it in the long run?

Think about it for a minute.

Do you have kids? A lot of foot traffic? People coming and going?

Then you know you will have dirty hands grabbing on the corners of walls, leaning on walls. Not to mention the odors from cooking among other things. Interior paint is made for this and is just a better choice in the long run from our experience.

Ventilation and Odor Concerns Using Exterior Paint Inside

Another significant concern about using exterior paint for indoor projects is the mere fact that the odor is going to stick around for months especially without proper ventilation.

Now, you can properly ventilate the room and reduce the order. But it’s still going to be much stronger than using the correct indoor options for your project.

Exterior paint contains more volatile organic compounds which is also known as VOC’s. VOC’s are the compound found within paint that causes odors and fumes. Without proper ventilation, exterior paint being used indoors is a potential health hazard.

VOC compounds that can’t properly ventilate are known to cause nausea, lightheadedness and can also be dangerous for pets, young children or a pregnant individual.

This is one of the most important considerations to keep in mind when deciding on which paint to ultimately use on your upcoming project.

Exterior Paints Are Often More Flammable Than Interior Paints

While we are about discussing the dangers of exterior paints being used incorrectly, I wanted to point out that exterior paints are also often oil-based. This alone makes exterior paints much more flammable than interior paints.

Therefore, it’s important to keep these considerations in mind. If you opt to use exterior paints, make sure to set up a safe workplace that’s free or any potential dangers that could cause a fire.

Using Exterior Paint Inside Your Home

Exterior paints do have certain benefits as we discussed earlier. But using them in the interior setting will hardly make a difference. Because indoors of the home will not be exposed to the harsh weather elements.

A big selling factor for exterior paints is their durability. So, exterior paint is always going to be more expensive than any interior paint you can purchase.

Of course, in some circumstances, a high-end premium interior paint may be equally as costly. But again, 99% of the time, your exterior paints are going to run you more money out of pocket to purchase.

Since we know you are gaining no additional benefits, it’s clear that this is a complete waste of money and resources.

So, you can certainly use exterior paint indoors. But it’s always going to be a more logical and budget-friendly choice to stick to interior paints for the indoors.

What Would We Recommend for Your Upcoming Project?

I’m a firm believer in using paints for their designated purposes. However, I do believe there are exceptions to everything.

If you haven’t purchased any paint yet and are simply doing research, I highly recommend using interior paint to complete your interior projects.

This is due to cost, safety, fumes and odor.

But, let’s say you got the color and finish you desired. Or maybe already had the paint or accidentally purchased exterior paint for an indoor project, you could still use it.

VOC compounds are volatile in nature. So with time, they gradually go away, after the paint has dried fully. It takes at least 1 whole month for the exterior paint to fully cure and dry out. So during this time, ensure proper ventilation in the room.

Should you have a low tolerance for fume, pets or plan on using the room right after it is painted opt for an interior grade paint.

Speaking of drying times, you might also want to check out how long it takes for spray paints to dry. Reading that guide will give you the perfect picture factors the paint drying time.

Final Words

While you certainly can make the decision to use exterior paint inside your home, I see it as a waste of money and overall not a good idea.

Interior paints are designed to serve their specific purpose and have traits that are desirable for the inside of your homes such as smooth finishes and more options.

Additionally, interior paints are designed to take the specific beating that the indoor area of the home presents such as handprints, dust, and other dander.

Another big note: Exterior paint is often more expensive. So all in all, applying exterior paint inside is not a great idea. However, the final decision is totally up to you.

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