Unglazed tile refers to ceramic or porcelain tile that lacks a glassy surface coating, leaving the natural clay or body visible; it is prized for its texture, durability, and slip resistance. This article explains what unglazed tile is, how it’s made, where it works best, and how to maintain it.
| Property | Unglazed Tile | Glazed Tile |
|---|---|---|
| Surface Finish | Porous, textured | Sealed, glassy |
| Slip Resistance | Higher (textured) | Varies (often lower) |
| Durability | Very durable (porcelain) | Durable but scratch-prone |
| Maintenance | Requires sealing, periodic care | Easier to clean |
What Is Unglazed Tile
Unglazed tile is ceramic or porcelain that does not receive a vitreous coating during firing, so the tile’s surface shows its natural body. It retains a matte, textured appearance and often exhibits the true color and grain of the clay or body material.
Types And Materials Of Unglazed Tile
Unglazed tile comes in several formulations, with key varieties including porcelain, quarry, and terracotta. Porcelain Unglazed Tile Is Dense And Low-Porosity, While Quarry And Terracotta Are More Porous.
- Unglazed Porcelain: Made from refined clay fired at very high temperatures; highly durable and suitable for heavy traffic and exterior use.
- Quarry Tile: Typically made from natural clays, fired at high temperature but less refined; common in commercial kitchens and outdoor spaces.
- Terracotta: Traditional red or brown clay with rustic aesthetic; more porous and generally for low-moisture areas unless sealed.
How Unglazed Tile Is Made
Manufacturing begins with natural clays and minerals, which are formed, dried, and fired in kilns. For porcelain, the body is highly refined and fired at higher temperatures to reduce porosity; no glaze is applied afterward.
After firing, tiles may undergo surface treatments such as honing, sandblasting, or polishing to achieve desired texture and slip resistance. These mechanical finishes define the look and performance of the tile without adding a glass coating.
Advantages Of Unglazed Tile
Unglazed tile offers specific performance and aesthetic benefits that make it a strong choice for many settings. Key advantages include durability, authentic appearance, and superior slip resistance.
- Durability: Unglazed porcelain is extremely hard and resists wear and abrasion well.
- Slip Resistance: Textured surfaces improve traction in wet or high-traffic areas.
- Colorfastness: Color penetrates the body, so scratches or chips are less visible.
- Aesthetic Authenticity: Natural, matte finishes suit rustic, industrial, and modern designs.
- Outdoor Suitability: Many unglazed tiles withstand freeze-thaw cycles and outdoor exposure when properly specified.
Disadvantages And Considerations
Despite strengths, unglazed tile has trade-offs buyers should evaluate. Main drawbacks are porosity for some types, a need for sealing, and potentially higher labor costs for installation.
- Porosity: Terracotta and some quarry tiles absorb water and stains unless sealed.
- Maintenance: Periodic sealing and appropriate cleaners are required to maintain appearance.
- Color Variation: Natural body tiles may vary more in shade and texture—this can be an advantage or challenge.
- Installation: Textured surfaces can make grouting and cutting more involved and may require specialized tools or adhesives.
Where To Use Unglazed Tile
Unglazed tile is versatile and suits many interior and exterior applications. It is especially appropriate where slip resistance and durability are priorities, such as patios, entryways, and commercial kitchens.
Interior Spaces
Use unglazed porcelain or quarry tiles in mudrooms, hallways, laundry rooms, and basements for abrasion resistance and low maintenance. Avoid unsealed terracotta in bathrooms unless fully sealed and maintained.
Exterior Spaces
Unglazed porcelain and quarry tiles with frost-resistant ratings are excellent for patios, pool surrounds, and walkways due to textured grip and weather resilience. Choose frost-rated porcelain and verify slip-resistance ratings for wet areas.
Installation And Best Practices
Proper installation preserves performance. Installers should follow manufacturer guidelines for adhesives, substrates, and expansion joints. Surface texture influences adhesive selection and back-buttering is often recommended for full coverage on textured backs.
- Substrate Preparation: Ensure a flat, clean, and stable substrate; use cement backer boards or exterior-grade mortar beds as required.
- Adhesive Choice: Use polymer-modified thinset for porcelain; consult tile and mortar manufacturers for compatibility.
- Grout Selection: Epoxy or high-performance cement grouts resist stains and moisture better than standard cement grouts in certain settings.
- Sealing: Seal porous bodies like quarry and terracotta before grouting to prevent grout haze and reduce absorption.
Cleaning And Stain Removal
Maintenance hinges on the tile body and whether it’s sealed. For sealed unglazed tiles, routine cleaning is similar to glazed tile; for unsealed, cleaners must be chosen carefully. Neutral pH cleaners maintain sealers and prevent surface damage.
- Daily Cleaning: Sweep or vacuum to remove grit; damp mop with a neutral cleaner for regular care.
- Stains: Address oil-based stains with a poultice or alkaline cleaner; use a mild acid (like diluted muriatic alternatives) only if recommended by the manufacturer and after testing.
- Sealer Maintenance: Reseal periodically according to product instructions—typically every 1–3 years for high-use areas.
Comparing Unglazed Vs Glazed Tile
Understanding differences guides selection. Unglazed tile exposes the body and emphasizes durability and texture; glazed tile offers a protective glass surface and a wider decorative palette. Choose Unglazed For Slip Resistance And Authentic Texture; Choose Glazed For Ease Of Cleaning And Decorative Variety.
| Factor | Unglazed Tile | Glazed Tile |
|---|---|---|
| Surface | Matte, textured | Shiny or matte glass coating |
| Stain Resistance | Lower if unsealed | Higher |
| Slip Resistance | Typically higher | Can be slippery unless textured |
| Design Options | Natural tones, limited patterns | Wide color/pattern range |
Buying Guide And Cost Considerations
Tile cost depends on material, size, finish, and brand. Unglazed Porcelain Typically Costs More Than Quarry Or Terracotta But Offers Superior Longevity.
- Price Range: Entry-level quarry or terracotta can be low cost; high-quality unglazed porcelain ranges higher but yields long-term value.
- Hidden Costs: Consider sealing, grout choice, and potential substrate prep when budgeting.
- Samples And Testing: Order samples and test them in the intended environment to assess slip, color variation, and porosity.
Standards, Ratings, And Selecting The Right Tile
Look for industry standards and ratings like PORCELAIN CLASSIFICATION, MOHS hardness, and COF (Coefficient Of Friction) for slip resistance. Higher COF Numbers Indicate Better Traction For Wet Environments.
- PEI Rating: Useful for glaze wear, but for unglazed porcelain, focus on body density and abrasion resistance.
- COF: For wet areas, aim for COF values that meet local code; ADA and local building codes may specify minimum values.
- Frost Resistance: For outdoor use in cold climates, choose frost-rated tiles with low water absorption.
Design Tips And Aesthetic Uses
Unglazed tile supports many design styles, from rustic to modern minimalism; mix textures and sizes for visual interest. Pair Textured Unglazed Floors With Smooth Wall Finishes To Create Balanced Contrast.
- Color Palette: Rely on natural earth tones; use variation in body color intentionally for a handcrafted feel.
- Patterning: Install straight, herringbone, or modular layouts to emphasize texture and scale.
- Transitions: Use threshold strips and compatible grout colors to create seamless transitions to other flooring materials.
Summary Of Key Takeaways
Unglazed tile is a durable, textured option ideal for slip-prone and high-traffic spaces; choose porcelain for performance and quarry or terracotta for rustic looks, and plan for sealing and proper installation to maximize longevity.
For technical decisions, consult manufacturer data sheets for porosity, COF, and frost resistance and hire experienced installers familiar with unglazed bodies and textured surfaces.