What is the Difference Between Interior and Exterior Paint?
In a nutshell, the difference between interior and exterior paint is that they serve different purposes due to the additives and resins used to make each type. Exterior paint needs to stay strong against some very specific exterior circumstances. Likewise, interior paint needs to withstand scenarios that don’t occur outdoors.
These different formulations between interior vs exterior paint also means that each is a different thickness, texture, and finish. Let’s take a closer look at the characteristics of each.
Characteristics of Interior Paint
Interior paint is known best for its use in aesthetics and home décor. There’s an infinite number of colors to choose from, and you can even get a custom paint match for just about any object you’d like.
But that’s not all. In recent decades, interior paint formulas have been revolutionized with new additives. You can get paint for your bathroom that isn’t negatively affected by steamy showers. Most kitchens have interior paint that stands up to scrubbing off stains and messes.
In general, most interior paints available today have some amount of anti-stain, easy clean, and scrubbable qualities. Most manufacturers will even sell different types of interior paint with different levels of hardiness. You can pay more to get a tougher, longer-lasting product.
Because interior paint shares the same space as humans, it has to be safe for us. That’s why it’s required for all interior paint to have either zero volatile organic compounds (VOCs) or a very low amount. There are quite a few health risks related to ongoing exposure to high VOCs, which is why this legislation was put into effect.
Characteristics of Exterior Paint
Exterior paint is rough and tough because it must look good in the rugged outdoors. Keep in mind this also means exterior paint needs to be formulated to handle every kind of weather.
Fade-resistant to protect against the sun, moisture-protected against rain and snow, and even anti-fungal properties to prevent mold growth are all characteristics of exterior paint.
On a molecular level, there are even more differences between interior vs exterior paint. The resins used to formulate exterior paint are very soft and flexible. That’s why exterior paint doesn’t easily crack as weather causes surfaces to contract and expand.
Even when fully dried and cured, exterior paint can essentially “flex” just like the surface it’s painted onto. This flexibility also allows the paint to endure moisture and temperature changes without bubbling, warping, or cracking.
There is a cost to all this flexibility, however. Exterior paint requires hours—sometimes days—of curing in sunlight before it’s fully dry and able to withstand any weather. Exterior paint also releases more VOCs than interior, which is unsafe for humans in enclosed spaces. This is the biggest reason exterior paint can’t be used indoors.
Cost Differences Between Exterior and Interior Paint
The cost differences between exterior vs interior paint varies a lot between brands and their sub-brands. For example, comparing prices of the highest-quality exterior paint from one company and the most affordable interior paint from another company won’t tell you much.
But with that in mind, most brands charge a bit more for their exterior paint than their interior paint. Exterior paint has far more resins, chemicals, attitude, and longevity than interior paint. So, it’s not a surprise that exterior paint usually has a higher price tag.
These days, most major paint manufacturers have a full range of interior and exterior paints at different price points. Budget options, middle-of-the-road choices, and top-of-the-line picks are all widely available.
Just keep in mind that you get what you pay for. Typically, you’ll need several more gallons of the cheaper paint to finish a job than you would’ve needed of the most expensive paint. This is because cheaper paint is usually slightly less pigmented and doesn’t do a great job of blocking the original wall color.
How to Choose Which Paint to Use
Now that you know the main differences between interior vs exterior paint, it’s time to make a choice. (1)
“A mismatch of paint with surface or interior conditions spells trouble down the road. So, do your research up front.” – Bob Vila
Ideally, you won’t be painting this same area again for quite a few years. It can also be very difficult to clean or sand off the wrong paint if you make a mistake. That’s why it’s important to get it right the first time.
Don’t buy any paint until you know what type of surface you’re painting (metal, wood, plaster, drywall, etc.) and the location of that surface (interior or exterior). Then it’s just a matter of choosing your color and gloss level. Higher glosses do better in areas like kitchens and bathrooms because they repel condensation and stains.
Can You Use Interior Paint Outside?
No, you can’t use interior paint outside for any type of project. As mentioned earlier, exterior paint has far more polymers and additives. This formulation is what makes exterior paint so durable, fade-resistant, and long lasting.
If you use interior paint anywhere outside, you’ll run into several issues. First, exterior paint is formulated to be much thicker than interior paint. Interior paint used outside would take quite a few coats to fully cover. Even in this scenario, no number of coats will look as good as exterior paint.
Interior paint isn’t designed to flex as its surface expands and contracts, so it’ll crack very easily. It’ll also fade quickly because interior paint contains no anti-fade additives.
Ultimately, there’s very little risk to your health or safety when you use interior paint outside. But you’ll never be able to achieve a beautiful end result like you can with exterior paint.
Can You Use Exterior Paint Inside?
No, you really shouldn’t use exterior paint inside. If you’ve read this far, you know that exterior paint contains much higher levels of VOCs than interior paint. Inhaling VOCs from exterior paint can cause serious illness to both humans and pets.
Exterior paint used indoors will dry to an uneven, undesirable finish. Your health is paramount, and putting your health at risk to use exterior paint inside will lead to an unattractive end result.
When you’re trying to choose between using interior vs exterior paint for your project, you’ll protect your health and get the best results by using each type as intended.
Hybrid Paints Can be Used Inside and Outside
In recent years, a category of “hybrid paints” has gained some popularity. Hybrid paints claim to be effective both indoors and outdoors, but this typically isn’t the case. Like many 2-in-1 or multipurpose products, hybrid paints don’t serve either purpose particularly well.
These products don’t have anti-mildew and anti-fade qualities that all exterior paints have. When it comes to interior applications, don’t be surprised if your sponge scrubs right through the hybrid paint on your walls. Basically, right now hybrid paints can be thought of as “Jack of all trades, master of none.”
As technology and science advance every day, new formulations of paint are being researched and tested. It’s absolutely possible that sometime soon, hybrid paint technology will experience a breakthrough. It just hasn’t happened yet.
Still Can’t Decide Between Interior Vs Exterior Paint? Let Us Help
It’s very beneficial for you to know the differences between interior vs exterior paint. The thing is, simply knowing the difference doesn’t complete your painting project. Like with any exterior orinterior painting job, you’ll have to mask and tape off the area. Then there’s purchasing the correct supplies for your specific project.
If you’re thinking painting sounds like a lot of work, you’re right! Set-up and clean-up tend to take far longer than most people estimate, not to mention the actual painting itself. But Same Day Pros is here to help!
You can get competitive quotes for your painting project with just a few clicks. All you have to do is let us know what needs to be painted, how soon you’d like to start, and provide a few more basic details. Within minutes, you’ll have competitive quotes to compare. Say goodbye to your home improvement woes and hello to Same Day Pros!
1. Bob Vila, The Basics of Paint Selection