Comparing And Contrasting Porcelain And Glazed Ceramic Tiles

As you peruse the tile samples at the flooring supply store, you'll notice two types of ceramic tiles: glazed ceramic and porcelain. Both types of flooring seem quite similar, but there are several notable differences. It's important to understand the differences between the two before you select a new flooring tile for your kitchen or bathroom.

Porcelain versus Non-Porcelain

When shopping for ceramic floor tiles, they are separated into two categories: porcelain and non-porcelain. Although porcelain and glazed ceramic are both comprised of kiln-fired clay, the major differences lie in how they're manufactured, the PEI rating and water absorption number.

Manufacturing of Ceramic Tiles

Both porcelain and glazed ceramic tiles are classified as ceramic tiles.

  • Porcelain tiles are made from highly refined white clay that is pressed and fired at very high temperatures. This creates a dense, hard material that is impervious and resistant to frost.
  • Glazed ceramic tiles are manufactured with either red or white clay and are fired at high temperatures, but not necessarily as hot as the temperatures used to fire porcelain tiles. Glazed ceramic tiles are durable, but not as water-resistant as porcelain.

PEI Rating

The surface wear rating system for ceramic tile is the method used to determine its wear expectations. Before you attempt to install this kind of tile in your home, it's important to know the surface wear rating so you can gauge whether or not a particular tile is appropriate for your needs.

According to the National Kitchen and Bath Association, the rating scale developed by the Porcelain Enamel Institute (PEI) accurately measures the surface wear ratings for all ceramic tiles. This PEI rating scale is recommended by the American Society for Testing and Materials (ASTM), so you can be confident when selecting a type of ceramic tile based on its PEI rating number.

  • Porcelain PEI Rating: Porcelain Tiles typically have a rating of 5 on the PEI scale of 1-5. This is the best possible rating number and is recommended for extra heavy foot traffic.
  • Glazed Ceramic PEI Rating: The actual rating numbers of glazed ceramic tiles vary, but they fall from 1 to 3. For flooring, make sure the tile has a PEI number of at least 3 so you'll know it's safe for floors.

Water Absorption

For kitchens and baths, the water absorption ratings are also important. Remember, the lower the number, the better the water resistance.

  • Porcelain: Tiles that are completely impervious to water (waterproof) are rated at 0.5 or lower. Porcelain tiles fit into this category.
  • Glazed Ceramic: These tiles fall somewhere within the vitreous category because they do provide a level of water resistance. Don't choose tiles with a water absorption rating higher than 3.0 for floors that are regularly subjected to moisture.

There's no need to get overwhelmed when shopping for ceramic flooring tile. Simply look at the tile's PEI rating and water absorption number to determine if it will be suitable for your kitchen or bath. If you have further questions, consult a professional contractor like Rainwood Interiors Inc.