Tile Grout: Complete Guide for Homeowners

What Is Tile Grout?

Grout is the cementitious or epoxy material used to fill the joints between tiles. Beyond aesthetics, grout provides structural support, prevents tile edges from chipping, and — in proper wet-area applications — contributes to the waterproofing system alongside the membrane behind the tile.

Types of Grout

1. Sanded Grout

Sanded grout contains fine sand aggregate and is used for joints 1/8" wide and larger. The sand prevents excessive shrinkage as the grout cures. It's the standard choice for floor tile and most wall tile with larger joints. The texture can scratch polished stone, so use caution on marble and limestone.

2. Unsanded (Non-Sanded) Grout

Unsanded grout is smoother and used for narrow joints (1/16" to 1/8"). Common for rectified porcelain tile with tight joints, wall tile, and glass tile. It adheres well to vertical surfaces and won't scratch delicate tile faces.

3. Epoxy Grout

Epoxy grout is a two-part system (resin + hardener) that sets chemically rather than through hydration. It's highly resistant to staining, moisture, and chemicals — making it ideal for kitchen floors, commercial kitchens, and anywhere grout maintenance is a concern. It's also significantly more expensive and harder to work with than cement-based grout.

Choosing a Grout Color

Grout color dramatically affects the look of your finished tile. Here are the key considerations:

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  Matching grout (same shade as tile) creates a seamless, monolithic look and hides variation. Good for large-format tile.
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  Contrasting grout highlights the tile pattern and grid. Classic subway tile looks great with dark charcoal or bright white grout.
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  Lighter grout shows dirt more easily. In kitchens and mudrooms, mid-tones are often more practical.
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  Dark grout can bleed color into porous tiles — test a sample before committing.

Grout Sealing

Cement-based grout is porous and should be sealed after full cure (typically 72 hours after grouting). Sealer penetrates the grout and reduces staining from spills, soap scum, and mold. Reapply sealer every 1–3 years in wet areas like showers. Epoxy grout does not require sealing.

Grout Maintenance Tips

• ✓ Clean grout with pH-neutral cleaner — avoid bleach and acidic cleaners which degrade grout over time
• ✓ Regrout heavily stained or cracked joints rather than trying to clean failed grout
• ✓ Replace caulk (not grout) at movement joints: tub/wall, floor/wall, and inside corners
• ✓ Address cracked grout quickly — water intrusion behind tile leads to expensive damage