Did you ever mistakenly painted the exterior with interior paints? Or vice versa?
Are you searching for the differences between exterior and interior paints?
This article is for you! We are discussing all three questions in this article with some possible help.
Stay with us!
Interior vs Exterior Paints
Paints are an integral part of our life. You will barely see a house without paint. Though painted surfaces look the same, they do not always share the same material.
There are four basic things that you will find in the paint-
- Pigment
- Resin
- Solvent, and
- Additives
Solvent is evaporated when the paint is dried leaving the other three in place. Pigment is the color you see that is bonded with the surface with the help of resin.
So, resin sticks the pigment to the wall. And the additives add extra values to the paint like mold, mildew, water, heat, cold, and fire resistance.
The core difference between the interior and exterior paints is the resin used to bind the paint to the surface. In the exterior, paints are exposed to heat, rain, and other freezing conditions.



So, exterior paints are made with a kind of resin that can absorb the expansion and contraction.
Read Our Take on The Best Drywall Primer Reviews!
On the other side, interior paints get a stable temperature. Thus it comes with a more rigid resin material that can enhance the look of the interior but can’t withstand harsh weather conditions.
Nowadays, you will find another important difference between the exterior and the interior paints.
That is additive material. Because the exterior is prone to mildew and mold growth, the paint must come with mold and mildew resistant additives. And that should also resist water from getting in touch with the surface under the paint.
But interior paints do not need such additives as you won’t experience mold growth in the interior wall unless you leave your home for a long time with moisture inside.
What happens if Exterior Paint is used inside?
This is a question that needs little explanation after the above description. Since the exterior paints contain mildewcide and other protecting materials, you can’t use them inside of your house.
Now, what if you used it mistakenly? The best practice is to remove the paint and repaint the surface with the proper painting. Because the mildewcide and other chemical additives can cause allergic problems to you.
If you have skin sensitivity, getting in touch with a newly painted wall (with exterior paint) can have you call your doctor.



What happens if Interior Paint is used Outside?
Now that you know the problem of getting interior painted with exterior paint, you should understand the opposite also.
As we have already discussed, exterior weather is not stabilized like interior and you can’t control it.
So, exterior paints are made considering the different weather conditions as well as an added extra protective layer against mold and other related things.
Since interior paints do not come with such a feature, it will be damaged within a few months. You will experience mold growth on the exterior surface and can have your wall damaged by harsh weather conditions.
The Solution
There is no easy way out when you put wrong paint on your wall. You have to remove all the paint you have applied on the surface and repaint it with the right one.
However, some manufacturers do not divide the exterior and interior paints. They make paints that can withstand all kinds of abuse without compromising the quality of the color. If you have applied paints that fall under this category, you should not worry about anything.
Some other categories of paint are made for interior or the exterior but can be used alternatively with one another. Choosing this type can also relieve you from removing and repainting task.
If you have anything more to know or want to share any experience with us, leave a comment below. We appreciate the interaction of our visitors with us.
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