If you've ever found yourself staring at leftover paint and wondering, "Can I use this interior paint for my porch?" — you're not alone. At Randalls, we often hear this question from homeowners looking to make the most of their paint supply. While it might seem convenient to swap interior and exterior paint, the short answer is: you really shouldn't — and here's why.
The Key Differences Between Interior and Exterior Paint
Paints are formulated with different ingredients depending on where they’re intended to be used. Here's a breakdown:
Interior Paint is designed for beauty, ease of cleaning, and low odour. It prioritizes smooth finishes and resistance to scrubbing.
Exterior Paint is built to withstand the elements — rain, UV rays, snow, mildew, and fluctuating temperatures. It contains additives that make it more durable outdoors.
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What Happens If You Use the Wrong Paint?
Using Interior Paint Outside: The paint will not stand up to moisture, temperature changes, or UV exposure. It will peel, fade, and crack quickly — sometimes within weeks.
Using Exterior Paint Inside: Exterior paints often release higher levels of VOCs (volatile organic compounds), which can be unsafe to breathe in enclosed spaces. Plus, they don’t always give the smooth, polished finish you want on interior walls.
🛑 Bottom line: Interior and exterior paints serve very different purposes. Using the wrong one can lead to poor results, wasted money, and potential health concerns.
When Might a Crossover Be Safe?
There are very few exceptions, such as:
Garage walls that aren't fully insulated may benefit from exterior paint for added durability.
Interior items like a plant pot or chair that will be moved outdoors can be painted with exterior paint — but always check with a paint expert.
Need advice? Reach out to our team for help
How Randalls Can Help
Whether you're repainting a bedroom or refreshing your deck, our paint experts at Randalls will:
Recommend the best interior or exterior paint line for your surface.
Help you choose the right finish for durability and style.
Offer colour consultation services if you’re unsure of what tone works best.
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Final Thoughts
So, can you swap interior and exterior paints? Technically, yes — but you really shouldn’t. They’re made to do different jobs, and using the right paint ensures a longer-lasting, better-looking result.
Have more questions about your project?
📞 Contact us or stop by your nearest Randalls location. We’re happy to help you get it done right the first time.