Tiles Technical Characteristics
Tile Materials
Tiles are manufactured from a variety of materials, each possessing distinct technical attributes. Porcelain tiles are renowned for their high density, low water absorption rates (typically less than 0.5%), and exceptional durability, making them suitable for high-traffic commercial and residential areas, including outdoor use. Their through-body composition often resists chipping and wear visibility. Ceramic tiles, conversely, are generally less dense and have higher water absorption, commonly featuring a glazed surface. They are versatile and widely used for wall and light-to-moderate traffic floor applications where their decorative potential is a primary factor. Natural stone tiles, such as marble, granite, travertine, and slate, offer unique aesthetic variations and geological authenticity. However, they often require sealing to protect against staining and moisture ingress, and their porosity and hardness vary significantly by stone type, impacting durability and maintenance.
Porcelain Tiles
Porcelain tiles are a type of ceramic tile with a water absorption rate of 0.5 percent or less, as defined by ASTM C373. They are produced from denser clays fired at higher temperatures, resulting in a significantly harder and more durable product. This low porosity makes them highly resistant to staining and frost, ideal for both indoor and outdoor applications in various climates. Full-body porcelain tiles have consistent color and pattern throughout the tile thickness, making chips less noticeable.
Ceramic Tiles
Ceramic tiles are generally made from red or white clay, along with other minerals, and fired at lower temperatures than porcelain. They typically have a higher water absorption rate. Most ceramic tiles are glazed, providing a protective and decorative surface that can be glossy, matte, or textured. Glazed ceramic tiles are suitable for interior wall applications and moderate-traffic residential floors, but their wear layer is confined to the glaze.
Performance Ratings
PEI Rating
The PEI (Porcelain Enamel Institute) rating system, also known as the abrasion resistance rating, measures the durability of glazed ceramic and porcelain tiles against surface wear. This rating ranges from PEI Class 0 to PEI Class V. Class 0 tiles are suitable for walls only, as they offer no foot traffic resistance. Class I is for very light traffic, typically bathroom walls or areas with bare feet. Class II is for light traffic, suitable for residential bathrooms. Class III is for moderate traffic, appropriate for most residential applications. Class IV is for heavy traffic, suitable for all residential and some commercial applications. Class V is for very heavy traffic, ideal for all residential and commercial uses.
Water Absorption Rate
Water absorption is a critical technical specification for tiles, indicating their porosity and suitability for various environments. Tiles are classified based on their water absorption percentage: non-vitreous (>7%), semi-vitreous (3% to 7%), vitreous (0.5% to 3%), and impervious (≤0.5%). Impervious tiles, primarily porcelain, are ideal for wet areas like showers, outdoor installations, and frost-prone regions due to their resistance to moisture penetration and subsequent damage from freezing and thawing cycles.
Slip Resistance
Slip resistance is measured by the dynamic coefficient of friction (DCOF), which quantifies the frictional resistance of a tile surface when wet. The ANSI A326.3 standard specifies a minimum DCOF value of 0.42 for tiles installed in level interior spaces expected to be walked upon when wet. Higher DCOF values indicate greater slip resistance, crucial for areas like commercial kitchens, entryways, and shower floors. Textured finishes and unglazed surfaces generally exhibit higher DCOF values compared to smooth, glossy finishes.
Tile Features
Rectified Edges
Rectified tiles are ceramic or porcelain tiles that have been precisely cut or ground after firing to achieve extremely uniform dimensions and sharp, 90-degree edges. This post-production process allows for much tighter grout lines (e.g., 1/16 inch or less), resulting in a more seamless and contemporary appearance with fewer visible grout joints. This feature also contributes to a smoother, more monolithic floor or wall surface. Non-rectified tiles, also known as pressed or cushion-edged tiles, have slightly rounded or irregular edges, requiring wider grout lines to accommodate manufacturing variances.