8. Concrete & Terrazzo Geometric Wall Medallion

Industrial concrete and vibrant terrazzo aggregate form a resilient, sculptural art feature.

  • Introduction: Cast concrete and terrazzo medallions merge sculpture with graphic wall decor. Made from durable cast stone, these pieces are inherently moisture-proof, making them ideal for high-humidity and wet-zone bathroom walls.
  • What This Idea Means: This concept celebrates structural materials. By combining concrete with colorful marble chips, crushed quartz, and glass fragments, you turn industrial elements into an artistic centerpiece.
  • How to Make It:
    1. Construct a shallow circular or arched silicone mold using structural foam and silicone rubber casting compound.
    2. Mix high-strength white Portland cement with fine sand, acrylic fortifier, and marble aggregate chips (such as Thassos white, Verde Alpi green, and Nero Marquina).
    3. Pour the mix into the mold, vibrating it thoroughly to eliminate trapped air bubbles.
    4. Let it cure undisturbed for 72 hours.
    5. Demold the cast and wet-grind the surface with diamond polishing pads (starting at 60-grit up to 1500-grit) to expose the cross-sections of the colorful marble chips.
    6. Apply an impregnating stone and concrete sealer to lock out moisture.
    7. Mount to the wall using a heavy-duty concealed French cleat embedded during casting.
  • Tips and Variations:
    • Variation 1: Cast the medallion with half smooth pigmented charcoal concrete and half terrazzo for a two-tone look.
    • Variation 2: Inset a polished circular mirror into the center to combine art with functionality.
    • Mounting Safety: Use masonry anchors rated for the specific weight of your cast stone medallion.