Painting your interior walls is a great way to breathe new life into your home’s indoor environment. There’s nothing quite like the feel of a freshly painted room 🙂

Have you ever thought of painting your interior walls with leftover exterior paint? It’s still wall paint, so what’s the harm?

The truth is, exterior and interior wall paint serves two different purposes; they are made differently and while you can, technically, use exterior wall paint for your interiors, there are several things you need to understand about the differences between these two kinds of paint.

Let’s take a look at these differences and see if using exterior paint for interiors is a good idea.

Fumes and odor

One important difference between these two paints is their make-up. 

Compared to interior paint, exterior paint is designed to be very resistant to harsh weather conditions such as rain, intense sunlight, dust, and mold. To achieve this resilience, paint for exteriors is given various additives.

Many of these additives are highly volatile substances called volatile organic compounds (VOCs). The paint will continuously emit VOCs into your home’s air if you apply it to your indoor walls, and prolonged exposure to these compounds can lead to medical problems, like itchy eyes, flu-like symptoms, and asthma attacks.

Exterior paints also give off a strong, noxious odor which can make it difficult to breathe, causing headaches if used indoors. What’s worse is that these paints can give off this odor for days, and they can emit VOCs for many years.

Interior paint is much milder than its exterior counterpart since they don’t have many of these harmful chemicals in them, and they’re designed to be perfectly safe for a home’s occupants. There are also many low-VOC and eco-friendly interior paints available if you’re worried about your indoor air quality.

Paint for exterior walls aren’t very damage resistant

Paint for exterior use is designed to be extra resistant to environmental factors but isn’t very good at withstanding scratches and scrapes. 

Most exterior wall paints are made to be very soft; this allows them to flex and withstand outdoor extremes like temperature changes. Indoors, the paint will be exposed to a lot of indoor traffic, meaning it will need to endure furniture bumping into walls and scratching them or the occupants frequently touching them.

Exterior wall paint will start to flake and crack very quickly when used indoors because of all the physical conditions it’ll be exposed to.

Interior paint, meanwhile, is more resistant to physical damages and may have plastic added to them, making them dust and water-resistant. Thanks to this feature, you can even wipe off any dirt and stains from the wall without damaging the paint.


Most paints used for painting exteriors are oil-based and this makes them flammable to an extent. 

While a fire spreading indoors due to paint is extremely rare, many places inside a home may have potential fire hazards, like the kitchen stove or faulty electrical outlets; because of this, using exterior paints for indoor walls is a bit risky.

Quality of the finish

When you’re painting your interiors, one thing you need to be careful of is the finish. A poor finish will be very visible indoors and blemishes will easily stand out, making exterior paint a poor choice for interior painting.

Paint for exteriors has many additives to help it withstand the harsh conditions outdoors and because of this, the paint is usually thicker and rougher than indoor paint. The texture of this paint will not give you the smooth and elegant finish you’d expect from interior paint.

Exterior paint—not a great choice for interior painting

If you’re going to paint your home’s interiors, it’s much better to stick with interior paint since it’s designed especially for interior painting and is much safer to use. 

If you don’t have the right interior paint for your home, try getting in touch with professional painters in San Diego for help.