Tile Grout Selection Guide: Sanded vs. Unsanded, Epoxy, and Color Choices

Sanded vs. Unsanded Grout

The simple rule: use unsanded grout for joints under 1/8 inch; use sanded grout for joints 1/8 inch and wider. Why? Sanded grout contains fine aggregate that prevents shrinkage cracking in wider joints. Using sanded grout in tight joints (under 1/8") can scratch polished stone tile. Using unsanded grout in wide joints causes shrinkage cracks as it dries.

Cement-Based vs. Epoxy Grout

• Cement-based grout (most common): Easy to work with, wide color selection, lower cost ($3–$10/bag). Porous — requires sealing (especially for light-colored grout) to prevent staining. Standard choice for most residential applications.
• Epoxy grout: Two-part system (resin + hardener). Stain-proof, chemical-resistant, doesn't require sealing. Harder to work with — sets fast, difficult to clean off tile before curing. Best for commercial kitchens, shower floors, and anywhere chemical resistance or stain prevention is critical. More expensive ($15–$30+/bag).
• Pre-mixed/urethane grout: Easier to work with than epoxy, more stain-resistant than cement. Single component, no mixing. Less durable than epoxy long-term.

Grout Color Selection

Two main approaches: (1) Matching grout to tile creates a seamless, unified look that makes the tile itself the focal point. (2) Contrasting grout emphasizes the tile pattern and grid — particularly effective with large format tiles and geometric patterns. Light grout shows stains; dark grout hides them. For shower floors and heavily used areas, medium to dark grout is more practical.

Grout Quantity Calculation

Grout coverage depends on tile size, grout joint width, and tile thickness. Larger tiles (with fewer joints) need less grout. A 25-lb bag of sanded grout covers approximately 100–150 sq ft for a standard installation. Always buy 10–15% extra — dye lots vary between bags.