Are you thinking of using some leftover interior paint outside? The answer would be Yes, but it is much more complex than a one-word answer. Although the answer is Yes, interior paints are not designed to withstand the extreme environment of outside walls such as rain, UV, mildew, extreme temperatures, or snow.
In this article, we will look at the composition of interior and exterior paints to better understand how to utilize these paints to achieve the best results.
In General, paints fall into two categories: Oil-based and Water Based (latex and acrylic) Paints. Oil-based paints are becoming a thing of the past due to their harmful nature towards the environment and people. Nowadays most common choice is Water-based paint for both internal and external use.
To understand the difference between interior and exterior paints, one has to understand their chemical composition. The main difference between interior and exterior paints are adhesives and resins. Interior paints have distinctive characteristics which are best suitable for interior use, such as less odor or spatter resistance. Interior paints use binding resins, which are rigid to allow for easy cleaning and stain-resistant properties. Most commonly, vinyl acrylic resins (also used in spray paint for wood) are used in interior paints to make them scrub-resistant and washable.
Most exterior paints are made of chemicals to give them extra adhesiveness and are far more durable to withstand extreme conditions. Such Chemicals have hazardous properties making exterior paints dangerous if used in internal environments. The resins used for Exterior paints are softer that provide extra strength against fading, temperature changes, and moisture.
Knowing the chemical properties, it can be said that it is safe to use interior paints outside, but it is not recommended because it is less likely to withstand the conditions present outside. It might feel like a cheaper alternative, but it can be more expensive in the long term.
If interior paint is to be used outside, there is an alternative. Interior paint should be sealed with exterior sealers, and this is a temporary solution because it will not prevent fading, and the color of your paint will become yellowish. Using this method will cost an extra amount of work and money, so it highly recommended that you should use exterior paints for the outside of your home for longer durability and better looks.
Alternatively, Can I use Exterior paint for the inside?
NO!! Using exterior paints for the interior is not recommended due to its harmful nature. Exterior paints contain large amounts of VOCs (volatile organic compounds) as compared to interior paints. The only place exterior paint could be used inside is to use it for the garage, but that is also not recommended. Paints should be used as intended for longer benefits, more efficiency, and safety of the environment.
Interior paint is formulated to look better and give a greater look to the interior of your home and is safer to use. I painted outside, it will not last very long, and soon, your outside will start looking rough and yellowish due to fading.
Exterior paint is best suited for the outside environment to provide more durability and less fading, but it is not safe to use internally.
We hope you have a better understanding of interior and exterior paints and why such paints should only be used for their intended purposes.