Interior versus exterior paint

Knowing the Difference: Interior vs. Exterior Paint

Can you use exterior paint inside? Whether you are hiring someone to paint something for you or you are considering doing the job yourself, it is important to know that there are differences in interior vs. exterior paint. If you plan to hire someone, one way to ensure that a painter knows its craft is if they understand the differences between the two types of paint. If they don’t, they are not reputable and not a professional painter.

interior and exterior painting

Types of Paint

There are two main types of paint that are used in commercial and residential use, and they are water-based interior and exterior painting and oil-based paints. These two mediums may appear similar to the untrained eye, but they behave vastly differently depending on the environment they are used in. Here is a quick run-down of the main properties of these two paints formulated for specific purposes.

Exterior paints come in both a gloss and matte finish. Exterior paints are made of additives that help prevent fading, stop the growth of mildew, and resist tannin based stains.

Interior paints also come in a gloss and matte finish. Interior paints are not exposed to rain and do not come in contact with freezing temperatures so they are made of more rigid resins. 

can you use exterior paint inside

Choose the Right Paint

Can you mix interior and exterior paint? To better understand which paint is appropriate to use, it is important to understand the nature of paint, which is comprised of solvent, resin, additives, and pigments. Typically, the pigment of paint is a powder that is mixed with a resin to give it its viscous property. It is not the pigment but the binding resins that make up the difference between exterior and interior paint.

As for solvents and pigments, any pigment can be used in any paint regardless of what solvent or resin is added. While the resin binds the pigment, the additives present in the paint will vary, and depending on its intended uses, can be found in the paint to prevent mildew among other things.

When it comes to interior vs.exterior paint, the biggest factor in choosing the correct paint comes down to how it reacts to its environment. For an exterior wall, one must consider weather conditions when choosing between difference between interior and exterior paint. In some cases, interior paints can be used outside, but not the other way around. If an exterior wall is exposed to the elements, it can be completely ruined by the rain if it is painted with water-soluble paint.

The way paint dries will also affect your decision between paints, as oil paint gives off harmful fumes as it dries if kept in an enclosed area. These fumes can release VOCs or volatile organic compounds as it starts to cure and even after it’s finished curing, making exterior paint extremely unhealthy for indoor use.

You may choose to use interior latex paint with additives that give it weather-resistant properties. However, this same reasoning cannot be applied to oil-based paints for an interior painted surface due to the lasting fumes that oil can retain for years.

Keep in mind that mildewcides and fungicides in exterior paint can also give off an odor on muggy humid days and may even trigger allergy symptoms!

INTERIOR PAINT VS. EXTERIOR PAINT: WHAT’S THE DIFF?

All paint is made of the same basic ingredients: solvent, resin, additives, and pigments. Solvents are typically water for latex paint and mineral spirits for oil paint – but in both cases, the solvent is what evaporates as the paint dries, leaving behind the resin, pigment, and additives. Like interior paints, exterior paints come in different finishes from gloss to matte.

Interior and exterior paints have similar solvents and pigments, though some pigments fade faster than others and so are more commonly used in interior formulations. Exterior paint may also contain more pigment. But the real difference between them can be found in the additives and the resin.

Exterior paints need to be able to stand up to all kinds of weather conditions, from changing temperatures to UV rays to salty sea breezes and more. To compensate for the variable temperature conditions that paint on exterior walls will experience, exterior paint contains flexible resins that keep the paint looking good when the surface underneath expands and contracts. Exterior paint also contains additives that help prevent fading, stop mildew, and resist tannin staining.

Interior paint doesn’t get rained on and will likely never be subject to a big freeze, so it is made with more rigid resins.

These resins make interior paint less prone to damage from scuffing and also easier to clean.

Some people assume that because exterior paint has to stand up to more abuse than it will perform better indoors, too. But that’s actually not true! Exterior paint is, surprisingly, more prone to scuffing and scratches. It’s also typically going to release more VOCs (volatile organic compounds) as it cures and even after it’s done curing – making it less healthy for indoor use. Mildewcides and fungicides in exterior paint can also have an odor on humid days and may even trigger allergies!

The number one piece of advice we can offer homeowners is to use the right paint for the project like the pros do. Different paint formulations are recommended for different applications for a reason – it’s what will give you the best results!

However, you have to be aware of the possible risks in using exterior paint indoors.

Can You Use Exterior Paint Inside?

If you’ve ever got sick of redecorating the same interior wall over and over again due to dirty hands, you may get to thinking… what if I use exterior paint, indoors?

Well, before you do, it is probably a good thing that you’ve decided to do a little research first.

Using it on the inside of your home is guaranteed to be more durable, and able to withstand the everyday wear and tear living at home will cause.

On the other hand, there are precautions that must be considered as it can be very harmful if not used correctly.

These fumes from VOC are not only bad for the environment, but they can be dangerous if inhaled by humans and animals. A few common symptoms of VOC inhalation can include lightheadedness, headaches, and nausea.

These pain fumes can invade an entire home (and even a whole neighborhood as you may have noticed before).

People with weaker immune systems are more at risk of VOC’s harmful effects and may suffer from harmful respiratory effects. So if you’re wondering, can I use exterior paint inside, proper precautions need to be in place when using it, illnesses can even worsen to cancers and other life-threatening illnesses.