What Will Happen If I Use Interior Paint Outside

What if I use interior paint outside in Melbourne

There are differences between interior and exterior paints due to their additives. You can protect the inside of your house from heavy winds, rain and harsh weather, but not the outside. To withstand heat, cold, snow, rainfall, and the sun’s rays, exterior paints are formulated with weather-resistant chemicals and mildewcides. When you use interior paint outdoors, it won’t last and will eventually peel off your walls because of cracks.

Now the question is can I use interior paint outside? Although the short and sweet answer is yes, but it is not recommended.

Let’s take a look at what interior paint is made of and why it should be used indoors in this article. Also, we will discuss how to use it outside.

What Is Interior Paint?

Paints designed for indoor use are called interior paints.  In addition to adhering to different surfaces, they reflect or absorb light, and withstand the abrasion and wear of daily use and cleaning. Furthermore, interior paintings usually don’t have to endure the expansion and contraction caused by freeze-thaw cycles or harsher weather conditions.

4 Parts of Paints

Paints mainly consist of four parts- additives, binders, pigments and the base or liquid. The first three (additives, pigments, and blinders) make interior paint from exterior paint, and they are not interchangeable.

Interior paints have lower VOCs ( Volatile Organic Compounds) to minimize health problems due to off-gassing. VOCs keep the liquid from hardening and they vaporize when the paint dries.

Bases or Liquid

Water-based paints, such as acrylics and latex, and oil-based paints, such as alkyds, can be used for interiors. These paints offer different adhesive properties. High-gloss, semi-gloss, and flat sheens are available for both.

Water-Based Paints

Pigments and binders are combined with water to form latex paints. As the water evaporates, the paint dries more quickly, leaving behind the colour. It is easier to clean and maintain the colour of the painted surfaces made of polyester than those made of oil-based paints. It is usually less polluting than oil-based paints since it contains fewer VOCs.

Oil-Based Paints

Natural oils such as linseed, tung, soybean, or synthetic alkyds, are used in oil-based paints. These paints include pigments, a resin binder, and a solvent thinner. As the thinner evaporates, the resin and pigment form a durable, long-lasting hard coating.

Oil-based paints often emit more volatile organic compounds (VOCs), making them less environmentally friendly and more difficult to clean.

Also, read more about house painting in Melbourne.


Pigments, which can be organic or inorganic, provide colour for paint. The type of pigment used can also affect how long the colour lasts, which influences how often the walls need to be spruced up or repainted. Organic pigments, which are either vegetable or animal in origin, are naturally transparent.

They have traditionally been less durable than inorganic pigments, but modern chemistry is changing that. Inorganic pigments are solid mineral colours that occur naturally but are modified for use in the production of paints.

On the other hand, inorganic pigments have been discovered in 30,000-year-old cave paintings. All white pigments are derived from inorganic sources, the most common of which is titanium dioxide.


Binders hold the pigment together to form a long-lasting film on a surface. Plastic-like polymers offer improved adhesion to various surfaces as well as resistance to abrasion and household cleaners. Binders in latex paint should be 100 per cent acrylic, not a blend. Drying oils such as tung, linseed, or modified oils are commonly used in oil paints.

If I Use Interior Paint Outside?

There are numerous reasons why you might want to use interior paint outside. Some of the reasons we have heard are that it’s less expensive, you want to use up leftover paint, or you like the colour. However, while interior paint can be used outside, it should not be.

If you insist on using interior paint outside, seal it with one or two coats of exterior-grade clear-coat sealer. It may extend the length of time it will adhere depending on the amount of exposure to the elements, but it will not necessarily prevent it from fading, and the sealer may be yellow.

Some people are unsure whether interior paint can be used as an exterior painting. You can use it as a primer for a variety of reasons, including cost-cutting. It will need to be lightly sanded to improve adhesion before being covered with a quality exterior paint of the same base.

What Happens If You Use Interior Paint Outside By Accident?

Accidents happen, whether you grabbed the wrong can of paint or simply weren’t aware of the difference until it was too late. It’s not the end of the world if you use interior paint outside. It simply means you’ll have to repaint the surface in two to five years rather than ten to fifteen.

Interior paint is designed for use indoors and is best suited for that purpose. The paint can be used outside, but it will not withstand extreme weather, and you will need to repaint it sooner than expected.

I hope you now have a better understanding of interior paint, why it’s called that, and what happens if it’s used outside.

Related posts