Interior Paint vs Exterior Paint: What’s the Difference?

Choosing the right paint is just as important as choosing the right colour. Interior and exterior paints are designed for very different environments, and using the wrong one can lead to poor results, peeling, and costly repairs. Understanding the difference between interior paint and exterior paint helps ensure a long-lasting, professional finish for your home or business.

What Is Interior Paint?

Interior paint is formulated specifically for indoor environments where surfaces are protected from weather but exposed to daily wear and tear.

Key Features of Interior Paint

• Designed for low moisture and stable temperatures

• Easy to clean and maintain

• Low-odour and low-VOC options available

• Smooth, consistent finish

Interior paint is commonly used on walls, ceilings, doors, skirting boards, and trim.

What Is Exterior Paint?

Exterior paint is built to withstand harsh outdoor conditions, including rain, wind, sunlight, and temperature changes.

Key Features of Exterior Paint

• Weather-resistant and waterproof

• UV-resistant to prevent fading

• Flexible to handle expansion and contraction

• Resistant to mould, mildew, and algae

Exterior paint is used on brickwork, render, wood, metal, and outdoor trims.

Key Differences Between Interior and Exterior Paint

1. Durability

Exterior paint is far more durable and flexible to cope with weather changes, while interior paint focuses on resisting scuffs and stains.

2. Weather Resistance

Exterior paint is formulated to protect surfaces from moisture, UV rays, and temperature fluctuations. Interior paint is not designed for these conditions.

3. Cleaning and Maintenance

Interior paints are easier to clean and are designed to handle fingerprints and marks. Exterior paints prioritise protection over regular cleaning.

4. VOC Levels

Interior paints often have lower VOC levels for better indoor air quality. Exterior paints may contain stronger additives to protect against mould and weather.

5. Flexibility

Exterior paints expand and contract with weather changes, preventing cracking and peeling. Interior paints remain more rigid.

What Happens If You Use the Wrong Paint?

Using interior paint outside can result in:

• Peeling and cracking

• Fading from sunlight

• Water damage

Using exterior paint indoors may cause:

• Strong odours

• Poor air quality

• Unnecessary chemical exposure

Choosing the correct paint ensures safety, durability, and appearance.

Why Professional Advice Matters

Professional painters and decorators understand which paints work best for each surface and environment. They ensure:

• Correct product selection

• Proper preparation

• Long-lasting results

• A flawless finish

This expertise helps avoid costly mistakes.

Final Thoughts

Interior paint and exterior paint serve very different purposes. While interior paint focuses on appearance and easy maintenance, exterior paint is designed to protect against the elements. Choosing the right paint for the right space ensures your surfaces stay protected and look great for years to come.

When in doubt, consult a professional painter and decorator for the best results.