YES!
The key to using a small tile on a shower floor is the proper waterproofing. Using a topically applied fabric waterproofing adds greatly to the compressive strength of the tiled surface. This eliminates the risk of denting the custom foam shower base.
Installing small tiles, such as penny rounds or mosaics, over a prefabricated or custom foam shower base is a popular design choice that combines modern efficiency with classic aesthetics. While foam pans are engineered for high durability, using small-format tiles requires specific standard installation techniques to ensure long-term stability and waterproofing integrity.
The Benefits of Small Tiles on Foam
- Superior Slope Adaptability: Foam shower pans are pre-sloped toward the drain. Small tiles (under 2×2 inches) naturally conform to these contours much better than large-format tiles, which often require complex “envelope cuts” to avoid lippage. This is particularly true when the drain isn’t centered.
- Enhanced Slip Resistance: The high frequency of grout lines in small-format tile installations significantly increases traction underfoot, making the shower floor safer when wet.
- Design Flexibility: Mosaics allow for intricate patterns and custom borders that can be seamlessly integrated into the foam base’s factory-precise slope. Custom foam shower bases can be made in any size, in any shape, and with the drain in any location.
Critical Installation Considerations
Despite the benefits, during the construction phase foam is more susceptible to “point loading” than traditional mortar beds. This occurs when a small surface area (like a single penny tile) receives a high amount of pressure, potentially causing the foam beneath to compress or the waterproofing membrane to puncture. Since most showers get only bare foot traffic, this isn’t an issue.
To prevent failure, follow these industry best practices:
- Check Manufacturer Limits: While some brands like Built with Foam state there is no size limit when using commonly available waterproof fabric membranes as shown in this video. Others like Schluter may recommend a mortar base for small tiles under heavy loads. Always verify the specific tray’s warranty requirements.
- Use High-Performance Grout: For tiles smaller than 2 inches, experts often recommend using epoxy grout (e.g., LATICRETE SpectraLOCK PRO) . Epoxy grout is rigid, helping to distribute weight across multiple tiles and reinforcing the entire assembly.
- Optimize Thinset Coverage: Use a high-quality modified thinset specifically rated for your foam system. For mosaics, a 3/16″ or 1/4″ V-notch trowel is typically used to prevent “squeeze-out” while ensuring at least 95% coverage.
- Flood Testing: Before laying any tile, perform a 24-hour flood test to confirm the foam base and its membrane are 100% watertight.
Maintenance and Longevity
Small tiles mean more grout, which translates to more cleaning. If using traditional cementitious grout, ensure it is sealed regularly to prevent mold growth in the many joints. If longevity is your primary concern, choosing porcelain mosaics over natural stone can reduce the risk of water absorption and staining over time.
These installation guides offer tips on tiling shower pans with small tiles and explain how to achieve good traction with grout lines.