Different Porcelain Tile Grades and What They Mean for Your Space

After seeing a large number of users searching "Are all porcelain tiles the same quality?",  one thing is clear: people are not aware of the different grades of porcelain tile. This is a big deal!

In this blog post, we'll look at how to determine what grade of porcelain tile is best suited for your project and explain why it's important to use the right one. Whether you're selecting tiles for residential bathrooms, commercial spaces, or outdoor applications, understanding porcelain tile quality grades will help you make the optimal choice for your installation area.

What Is the Porcelain-Making Process?

Porcelain tiles are made from a refined mixture of sand, feldspar, silica, and kaolin clay, along with other minerals. The manufacturing process creates a non-porous material that's highly resistant to moisture and stains. Let's examine each step:

• Forming: The forming stage in the porcelain-making process requires careful precision and artistry. Clay-based creations are either hand-shaped using techniques such as pinching and coiling, or they are pressed into molds. The clay forms a shape that is then dried to get rid of excess moisture.
• Glazing: Glazing is the process of applying liquid glass to the surface of a ceramic or porcelain piece. This is done either by dipping or spraying and then firing it in an oven, which causes the glaze to fuse with the object's surface.
• Decoration: Decorating porcelain is a long-standing tradition that adds color, texture, and protection. Common methods include hand-painting with brushes or sponges, staining by dye immersion, and image transfers using a special process.
• Firing: This process involves heating the piece at temperatures up to 2,400 degrees Fahrenheit or higher, depending on the specific types of porcelain being manufactured. This heat causes the pieces to become harder and more durable by forming a glass-like layer on the surface.

What Is the PEI Rating for Tile?

The PEI rating, or Porcelain Enamel Institute rating, is one of the most important factors to consider when considering various porcelain tile grades for your project. Porcelain tiles are rated on their resistance to abrasion, known as the PEI rating. PEI ratings range from 0 to 5, with 0 indicating no foot traffic and 5 indicating the highest durability for heavy commercial and industrial use. The PEI rating helps determine the durability and functionality of porcelain tiles, helping you select the right tile for your living space.

What Are the Different Grades of Porcelain Tile?

There are five different porcelain tile quality grades. Do all porcelain tiles have a grade? Yes, and each grade has its own characteristics and can be used for different projects. But first, a question we've seen a lot: is class the same as grade in porcelain tile? Yes!

Here's a quick reference guide to help with selecting tiles based on your project needs:

Grade 1 Porcelain Tile

So, what is grade 1 porcelain tile? And what does grade 1 porcelain tile mean? Grade 1 is the lowest grade of porcelain tile. Grade 1 is the least durable and is intended primarily for wall use, such as kitchen backsplashes and bathroom walls, or for light-duty residential floors. It isn’t suitable for areas with heavy foot traffic due to its lower abrasion resistance.

Grade 2 Porcelain Tile

Grade 2 porcelain tile is an attractive and economical choice that is best used as flooring for rooms that don't get a lot of foot traffic, such as bathrooms and bedrooms. And as wall coverings, Grade 2 tiles provide beauty as well as function. However, they're not recommended for family rooms, living rooms, or other high-traffic areas.

Grade 3 Porcelain Tile

Grade 3 porcelain tiles are a great choice for residential and light commercial settings. Featuring high shade variation and durability, these tiles can stand up to moderate foot traffic and everyday wear-and-tear, making them suitable for kitchens, family rooms, hallways, countertops, outdoor porcelain tile, and even light commercial applications such as offices or small shops. This grade is ideal for residential areas where you need a balance of durability and aesthetic appeal.

Grade 4 Porcelain Tile

Grade 4 porcelain tiles are designed for heavy traffic and are ideal for commercial installations such as restaurants, shops, offices, and other spaces where day-to-day wear and tear is expected. Due to their superior strength and durability, they can also be used in residential settings such as laundry rooms and mudrooms. Grade 4 porcelain tile can also make an excellent choice for patios or outdoor living spaces. When choosing tile for commercial applications, Grade 4 offers the needed durability for heavy commercial use while maintaining lower costs than Grade 5.

Grade 5 Porcelain Tile

What is the best grade of porcelain tile? Grade 5! Grade 5 porcelain tiles make up the top porcelain tile grade rating and are the toughest type of tile available, making them perfect for areas with heavy foot traffic and where durability is key. They are perfect for commercial spaces such as hospitals, shopping malls, schools, stores, public spaces, and airports due to their high resistance to wear and tear as well as harsh chemicals. They can also be used in residential homes for steps, stairways, entryways, and other high-traffic areas.

Other Porcelain Tile Durability Factors to Consider

There are other factors that can affect the durability of porcelain tiles that involve the grades of porcelain tile discussed.

Porcelain Tile Types: Glazed vs. Unglazed

When considering the type of porcelain for a project, aside from porcelain grades, it is important to take into account the various types and applications:

• Unglazed porcelain tiles: Unglazed tiles are full-bodied with consistent color throughout, making scratches less noticeable. They're ideal for high-wear areas, including outdoor and heavy-use settings.
• Glazed porcelain tiles: Come in two varieties — printed tiles and color-bodied tiles. Color bodies are easy to clean and offer vibrant colors, while printed tiles can create unique patterns and designs. They are excellent for wall applications and residential settings where aesthetics matter.

Water Absorption

The water absorption rating of porcelain tile can also be an important factor to consider. Porcelain tiles are denser than ceramic tiles and therefore have a lower water absorption rating. This is especially important when it comes to cleaning porcelain tiles since water and stains can easily seep into porous tiles.

Slip Resistance Rating and Coefficient of Friction

Slip resistance is an important factor to consider when selecting porcelain tile for your project. The American National Standards Institute recommends a coefficient of friction of 0.60 or higher for commercial floors and a rating of 0.42 or higher for residential bathrooms, pools, and laundry rooms. Tiles with a lower porcelain tile grade should not be used in slippery or wet areas. Always check tile ratings for COF values before selecting tile for these applications.

Tile Thickness and Strength

Thicker tiles (8mm–12mm) are stronger and more durable, so they’re ideal for high-traffic floors and outdoor spaces. When selecting tiles for heavy commercial use or areas where professional installation of natural stone alternatives isn't feasible, thicker porcelain tiles provide excellent performance. It’s no surprise that lower-quality or thinner tiles may crack under pressure in commercial applications.

Scratch Resistance

The scratch resistance of a tile should also be taken into consideration when making your selection. Understanding the difference between A-grade and B-grade porcelain tile is key: Grade A offers top quality with no visible flaws, while Grade B may show slight color or surface variations but remains structurally reliable.

Suitable Applications

It's also important to consider the various applications and how they might affect the performance of each type of tile.

• Heavy commercial: Ideal for areas that see high levels of foot traffic or regular use, such as airports, shopping malls, hospitals, and schools.
• Commercial: Best for lightly trafficked areas such as office buildings or retail stores.
• Heavy residential: Suitable for areas of residential spaces that need to be highly resistant to wear and tear and require a higher level of durability, such as bathrooms, kitchens, and laundry rooms.
• Light residential: Perfect for bedrooms, bathrooms with minimal traffic, and decorative wall use only.

How to Check the Quality of Porcelain Tile

Many factors must be taken into consideration before choosing which porcelain tile to use in a project. Strength, color, and design are all important elements that influence tile selection. Here's exactly what to check to ensure quality:

• Tile grade: Indicates the tile’s overall quality. Grade 1 is the most delicate (best for walls), while Grade 5 is the most durable, suitable for high-traffic commercial areas.
• Visual inspection: High-quality tiles have clean edges, consistent color, and no chips, cracks, or surface defects.
• Water absorption: True porcelain tiles absorb less than 0.5% water, making them ideal for moisture-prone areas like bathrooms and kitchens.
• Glazed vs. unglazed: Glazed tiles offer enhanced stain resistance and a decorative finish, while unglazed (full-body) tiles are more durable for heavy use.
• Consistency across tiles: Compare tiles from the same box; high-grade tiles will show consistent color, thickness, and finish.

By evaluating these key factors, you'll be better equipped to choose porcelain tile that not only fits your style but also meets your space’s demands in terms of strength and longevity.

Make the Right Tile Choice: Talk to the Experts

Summing up, understanding the various types of porcelain tile and their applications is essential to choosing the right grade for your project. At Stone Center, we’ve been helping customers make confident tile choices since 1952, offering a wide selection of top-grade porcelain tiles to suit any project.

Our team has the knowledge and expertise to help you choose the best possible solution for your application. Need expert help choosing the right tile? Contact us today, as we’re happy to assist.