You’re not the only one who wonders if exterior paint can be used inside the garage of a house. Many people believe that exterior paint must be better if interior paint is excellent for their walls. While this assumption may be sensible, it is not always a good one.

Hence, before choosing between flat, satin, and semi-gloss paint, you’ll need to determine which paint is best for interior surfaces. Because they are formulated differently, interior and exterior paints perform differently. To paint your room like an expert, you must first understand the fundamental distinctions between the two types of paint and why you should avoid using exterior paint inside.

What’s the Difference Between Interior and Exterior Paint?

Even though interior and exterior paints look the same at first glance, they are made differently and have different effects. The main difference between interior and exterior paint is that interior paint has binding resins, pigments, and additives, while exterior paint does not.

#1. Exterior Paint 

Exterior paints are made without hard-binding resins, so they can stretch and shrink as the temperature changes around them. Also, exterior paints are meant to survive anything from blazing heat and harsh sunlight to freezing conditions and the moisture that comes with rain, snow, and sleet (within reason, of course).

These paints are often very water-resistant. They often have chemicals that block UV light, which keeps them from fading, and some are made with additives that keep mold and mildew from growing. These compounds can be fairly dangerous, but more on that later. They might make rich colors for exterior paint that protects your siding and other exterior features.

#2. Interior Paint 

Although exterior paint is designed to resist whatever Mother Nature can throw at it, indoor paint is designed to endure whatever you and your family can throw at it. Interior paints can withstand the bumps, scratches, and scuffs of everyday life because they are made of hard resins. They are also easy to clean.

Indoor paints also contain chemicals that minimize drying time and evenly distribute color. They are also specially designed to withstand stains, fading, and yellowing.

Can You Use Exterior Paint Inside

Because exterior paint is robust and fade-resistant, it may seem enticing to apply it inside your home. Yet, because of the dangerous chemicals that can be discharged into the air, it is not recommended that you use exterior paint inside your home.

Homeowners may think that using exterior paint inside is a good idea because it lasts for a long time. Yet, even though the exterior paint is available in a variety of colors and can be dried indoors, you shouldn’t use it on your interior walls for the following reasons:

  • The additives required to make exterior paint durable outdoors are not meant to be used within. The higher concentrations of resin used in exterior paint are designed to cure and mature outdoors, away from indoor air quality.
  • Outdoor acrylic latex paint has more VOCs than inside paint. This means that the paint’s off-gassing will be unpleasant at best and perhaps dangerous at worst, particularly in the presence of those who have allergies, breathing issues, or chemical sensitivities.
  • When applied in tight places, the mildew-preventative chemicals in exterior paint can create odors and even allergic reactions.
  • True enamel or oil-based paints are a no-no for interiors because of their poisonous fumes and may be outlawed for both interior and exterior use depending on where you reside.
  • Exterior paints, despite their resilience for outdoor circumstances, are more prone to scuffing and scratching when applied indoors.

Can You Use Interior Paint Outdoors?

Using interior paint on a house exterior isn’t hazardous to your health, but it also doesn’t make much sense. This is why:

  • Because interior paint lacks the same resins, fungicides, and other additives as exterior paint, it will not withstand the elements, even when applied to a sheltered location such as a front door on a covered porch.
  • Interior paint is prone to crazing (hairline cracks) and cracking since it is not designed to expand and contract with temperature fluctuations.
  • Because interior paint is not meant to be exposed to sunlight, its color will fade more quickly outside. 

 Can You Use Exterior Paint Inside a Garage

Simply put, garage walls painted with exterior paint are not safe. Use interior paint for your garage walls instead of cutting corners to protect your health and the health of your family.

Exterior paints can be particularly harmful, according to the Environmental Protection Agency, because they contain volatile organic compounds (VOCs). As it dries, paint naturally releases chemicals into the air, but VOCs are especially toxic and are linked to many health issues. 

Because outdoor surfaces have adequate ventilation, this isn’t a problem for painting a park bench or a deck, but in a small, poorly ventilated garage, you can give yourself serious health issues just from one application of exterior paint. Even worse, VOCs can continue to be released by paint for several years in small amounts, even after everything is dry.

Is Exterior Paint on Garage Walls More Effective?

Exterior paint is durable, which is one of the reasons why people think about applying it on the inside of garage walls. The main difference between interior and exterior paint is that exterior paint is made with mold- and mildew-resistant additives, solvents that prevent fading, and even chemicals that protect against UV rays.

Do you need such heavy-duty garage paint? Your garage isn’t completely exposed to the weather, and your garage walls probably don’t wear and tear as much as the walls in the rest of your house. Even in non-climate-controlled garages, exterior paint on garage walls is not more effective than inside paint.

The best choice for painting the inside of your garage walls is durable interior paint, such as acrylic latex paint. Because it dries rapidly, is simple to clean, and has a long shelf life, this water-based paint is superior.

If you don’t mind waiting longer for your paint job to dry and you’re comfortable using chemicals such as paint thinners, you can use an oil-based interior paint such as alkyd resin. It’s always important to guarantee ventilation when painting for your safety, but oil paints require extra care. Make sure your workspace is well-ventilated, and if you’re working with oil paints, keep your garage door open because they might be more harmful to breathe in than water-based paints.

When to Use Exterior Paint Inside

There are a few exceptions to the rule that exterior paint should not be used inside a house garage. There are several situations in which it is safe to use exterior-grade paint indoors.

 #1. Use outdoor paint inside, when painting a storage shed or other outside building

The building could be a detached garage or a pool cabana that doesn’t have any rooms for sleeping. This kind of room isn’t used very often, so the toxic fumes from it aren’t likely to hurt your family or pets.

Because your family won’t be using the room, they won’t be exposed to VOCs, so painting such an indoor area with exterior paint would be a fantastic way to use up any remaining paint.

#2. Use exterior paint If you won’t be using the room for a few weeks or months

It takes several weeks for outdoor paints to degrade.  During this time, they produce toxic fumes that can cause illness if inhaled.

Using outside paint is safe if you have an outdoor building or storage area that you can stay away from for several weeks. You may always open the windows of such a building to let the gases out while it heals.
The paints are made from materials that are potentially toxic in enclosed spaces but are less so outside due to the amount of airflow.

What Happens If You Use Exterior Paint Inside the House?

When you use exterior paint inside the house, the chemicals in this paint that help prevent mold and mildew will produce fumes and odors likely to cause disease and trigger allergic reactions among people and pets.
Such paints are designed for use within open outdoor environments. They pose a variety of health concerns when utilized in enclosed locations with restricted airflow. Let’s dissect it.

#1. Your family may fall sick if you use exterior paint inside 

These paints are high in volatile organic compounds, which pose a health risk. Employing these paints in your home exposes your family to VOCs. They might become ill as a result of this.

Some family members who are sensitive to strong odors may have adverse reactions to the paint’s strong odors. Different stimuli cause diverse reactions in people. As a result, severe allergic reactions can result in more serious health consequences.

#2. Applying exterior paint inside could raise the risk of damage.

If you paint interior rooms with exterior-grade paint, you may also lose money.
These paints are designed to be stretchable to endure high-temperature changes outside. Nonetheless, because of their stretchiness, outdoor paints are softer than their indoor counterparts. An outdoor choice may not have the same amount of scratch resistance as top-quality interior paint, which will resist abrasion and look pristine for a long time.

What to Do If You Use Exterior Paint Inside?

Although it is feasible to apply exterior paint inside the house, it is not usually suggested because the paint is not intended for use indoor. But, if you must use the paint inside, consider the following steps to reduce the risks associated with utilizing exterior paints indoors.

#1. Stay away from abrasive cleaning, timepieces, and scuffs.

The purpose of interior paint is to survive scuffs, knocks, abrasive cleaning, and other similar physical effects caused by human activity.
Because they are designed to be elastic to endure major weather fluctuations, exterior paints are softer. As a result, when utilized indoors, they may be subject to physical impacts such as scratching and abrasive cleaning.

The best strategy to safeguard such a surface is to limit any physical impact that can damage it. Begin by limiting any activities that may cause it to become unclean enough to require abrasive cleaning, and then prevent knocking or scratching it as much as possible.

#2. Provide adequate ventilation in the area

Because of the right airflow, VOCs from exterior paint is mostly harmless outside.
When these paints are utilized in enclosed indoor environments, they constitute the number one danger factor. Because of this, if you paint an inside room with exterior-grade paint, you must address the ventilation issue.

To disperse any VOCs in that room, keep windows open or fans running most of the time. It is advisable not to use the paint first if you can’t control the ventilation. Only apply exterior paint in areas with access to fans, open windows, and doors.

#3. Protect yourself whenever within the painted room 

For a few weeks or months, the exterior paint will emit harmful vapors. Begin by reading the label or contacting the manufacturer about the maximum cure time of the paint.

Once you have this information, ensure you wear a respirator or special protective mask to filter the air whenever you use the painted room. Continue with this process until the off-gassing phase is through.

#4. Use a paint with the fewest VOCs if at all possible

Because of its water-based formula rather than an oil-based one, acrylic latex paint is likely to contain fewer volatile organic compounds. Ask the manufacturer for the product with the lowest amounts of harmful fumes before purchasing, unless you already have the paint at home.

This option will ensure that your space has fewer VOCs. It is preferable to choose the one with the quickest cure time. Keeping a painted room off your property for a few weeks is easier than keeping it off your property for six months.

Can I use exterior paint on the interior walls?

Because of the dangerous chemicals that can be discharged into the air, it is not suggested to apply exterior paint inside your home. Because exterior paint is robust and fade-resistant, it may seem enticing to utilize it inside your home.

Is it OK to use water-based exterior paint inside?

Due to the dangerous chemicals that can be discharged into the air, it is not recommended that you use exterior paint inside your home.

What is the difference between exterior paint and interior paint?

Various paints have diverse qualities since they are made for different reasons. Mildew and fade resistance are features of exterior paint. On the other hand, interior paint is designed to be washable and stain-resistant.

Can I use exterior paint and primer inside?

An interior/exterior primer is good to use if you’re painting both inside and outside. Instead, use separate primers indoors and outdoors.

How long does exterior paint last on walls?

Your exterior paint job should last 7 to 10 years.

How long is exterior paint harmful?

Even if you can no longer smell the paint fumes, you should wait at least 72 hours before returning to a recently painted room. To assist minimize the quantities of VOCs in the air, use an air purifier.


The inside walls of a garage or any other inside room should never be painted with exterior paint. The garage walls can be painted the same color as the rest of your house. Because it is long-lasting, quick-drying, and simple to clean, acrylic latex paint is the perfect sort of paint to use in your garage.

Even if your garage is heated, latex paint can be used. But, during painting and drying, you should stay away from excessive temperatures. You may need to temporarily heat or cool your garage to keep it between 50 and 90 degrees Fahrenheit (10 to 32 degrees Celsius)

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