Can you use exterior paint inside your house?
The short answer: you can roll exterior paint onto an interior wall and it will stick, but you shouldn’t. Exterior paint is formulated for sun, rain and temperature swings, not for indoor air, scrubbing or the close-up look of a living room. For any room you live in, use interior paint.
Why exterior paint is a different product
Paint is made of the same basic parts inside and out: pigment, a binder that holds it together, a liquid carrier, and additives. What changes is the job each formula is built for.
- Exterior paint uses softer, more flexible binders so the film can expand and contract with heat and cold without cracking. It carries additives to resist UV fading and mildew.
- Interior paint uses harder binders that resist scuffs and stand up to washing, and it is formulated to be lived with in a closed room.
Those exterior strengths are wasted indoors, and some of them become drawbacks.
The problems with exterior paint indoors
Indoor air and odor
Exterior paints can contain mildewcides and other additives that are fine in open air but are not meant to be breathed in a bedroom. They can also smell stronger and off-gas longer in an enclosed space. Interior paints are formulated with indoor air in mind.
Washability
Interior walls get hands, furniture, kids and pets. Interior paint is built to be wiped clean. A softer exterior film can hold onto scuffs and marks and does not respond as well to scrubbing.
The look up close
Interior paint is designed to level out smoothly and look even under lamps and window light. Exterior paint is designed to look good from the curb. Inside, you see every lap mark and texture.
Cure and feel
Because exterior binders stay flexible, the film can feel slightly soft or tacky longer indoors, where there is no sun to help it along. Shelves and doors painted with it can stick to whatever sits against them.
When exterior paint inside is reasonable
There are a few spaces where a leftover can of exterior paint makes sense:
- A detached garage or workshop
- A shed or storage room with good airflow
- A covered patio or porch ceiling that is technically outside
Anywhere people sleep, cook or spend the day, use interior paint.
What about Tucson’s heat and dry air?
Tucson interiors do not see the UV, monsoon rain or big temperature swings that the outside of a house does, so the main reasons to buy exterior paint simply do not apply indoors. Air conditioning keeps interior temperatures steady. What indoor walls in a desert home do need is washability and a finish that handles fine dust and frequent wiping, which is exactly what a good interior paint gives you.
The right paint for the room
Choose interior paint in the sheen that fits the space: flatter finishes for ceilings and quiet rooms, eggshell or satin for living areas, and harder satin or semi-gloss for kitchens, baths and trim. If you are not sure, a painter can match the product and sheen to each room.
Want to see a new color before buying any paint? Try it on a photo of your own room with our free color visualizer.
Interior painting in Tucson: process and pricing
Interior Painting in Tucson: prices, process and photos
Frequently asked questions
Can I use exterior paint inside my house?
Technically it will stick to a wall, but it is the wrong product. Exterior paint is formulated for UV, rain and temperature swings, and it can contain additives such as mildewcides that are not meant for indoor air. Interior paint is the better choice for any room you live in.
Is exterior paint safe to use indoors?
It is not designed for it. Exterior formulas can off-gas longer and smell stronger in an enclosed room, and they are not tested for indoor air quality the way interior paints are. Keep exterior paint outside.
Can I use leftover exterior paint in my garage?
A detached or well-ventilated garage, shed or covered patio is the one place leftover exterior paint makes sense. Avoid it in living spaces, bedrooms and anywhere air does not move freely.
Does exterior paint clean as well as interior paint?
Usually not. Interior paints are formulated to be scrubbed and wiped. Exterior paint is built to flex and shed water, so it can hold onto scuffs and hand marks on interior walls.
