Knowing the Difference: Interior vs. Exterior Paint

Eddie Shekari
December 31, 2018

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 painting

Types of Paint


There are two main types of paint that are used in commercial and residential use, and they are water-based paints and oil based paints. These two mediums may appear similar to the untrained eye, but they behave vastly different 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. 


used for exterior


gives off harsh fumes

solvent: mineral spirits


Water-based (also known as latex paint)

used for interior


light fumes

solvent: water

Interior vs. Exterior Paint

Choose the Right 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 a 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 a paint will vary, and depending on its intended uses, can be found in 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 interior paints and exterior paints. 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 rain if it is painted with a water-soluble paint.

The way a 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 exterior 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!

Leave it to the Pros

To ensure that your paint job is done with the right materials and executed professionally, it is recommended that you hire professionals. Pro Painters is a trusted company based in Houston with an A+ rating from the Better Business Bureau. With extensive experience in residential and commercial painting projects, your interior and exterior paint jobs are safe in the hands of the pros.

Free Estimate

Eddie Shekari

Eddie founded Pro Painters in 1995 to meet the growing need for high-quality residential and commercial painting needs in Houston. In nearly 20 years, Pro Painters has exponentially grown our client base, serving residents across the greater Houston area. Our core principles have helped us achieve the highest standard of workmanship and customer satisfaction. Our years of experience have allowed us to become an extension to our customers as the all-in-one solution for home makeovers.