Sanded vs. Unsanded Grout: Which One Do You Need?

Core Differences Between Sanded and Unsanded

What is sanded grout?

Sanded grout contains fine silica sand blended with cementitious binders and performance additives. The sand acts as a structural filler that resists shrinkage and boosts compressive strength, so joints stay full and stable as the grout cures. Because of this reinforcement, sanded grout is the default choice for wider joints—typically 1/8 inch and above—and for high-traffic floors or submerged areas where stress is constant.

What is unsanded grout?

Unsanded grout omits the sand, yielding a smooth, creamy texture that presses cleanly into narrow joints (generally less than 1/8 inch). That smoothness is gentle on delicate tile faces such as glass, marble, or polished stone, reducing the risk of scratching during placement and cleanup. Unsanded grout also produces crisp, refined joints in decorative mosaics and vertical installations.

Why the sand matters

Sand changes how grout behaves. With sand, the mix is stronger and less prone to shrink in wider joints; without sand, the grout finishes smoother for tight joints and sensitive surfaces. Matching this behavior to your tile, joint width, and location is the simplest way to avoid cracking, shading issues, or surface damage.

When to Use Unsanded Grout (Walls, Delicate Tiles)

Best applications for unsanded grout

Use unsanded grout for narrow joints on walls, backsplashes, shower surrounds (change-of-plane caulked), feature walls, and fine mosaic work. It’s the safer choice for polished marble, soft limestone, and clear or translucent glass tiles—materials that can scratch or show sand drag lines. In pools and fountains that include glass mosaic accents, unsanded grout helps maintain a smooth, uniform aesthetic along faces and edges.

Joint width guidelines

Keep unsanded grout to joints up to 1/8 inch. Beyond that, the lack of sand increases shrinkage risk as water leaves the grout, which can lead to hairline cracks, pinholes, or depressed joints. For the cleanest look, hold joint width consistent across the field and tool joints evenly during wash.

Benefits in wet environments

Water accentuates surface imperfections. Unsanded grout’s refined finish minimizes ridge lines and trowel marks that might otherwise show through clear water or strong sidelighting, making it a favorite for waterline mosaics and spa walls—provided the joint width stays within spec.

When to Use Sanded Grout (Floors, Wider Joints)

Best applications for sanded grout

Choose sanded grout for floors, patios, pool decks, and other high-wear surfaces where joints are 1/8 inch or wider. The sand improves load distribution, resists abrasion, and holds the joint profile under traffic. On exterior walkways and in submerged basins, sanded grout provides the mechanical “backbone” needed to resist movement, temperature swings, and hydraulic pressure.

Joint width guidelines

At 1/8 inch, either type can be used depending on tile and location, but sanded is generally preferred for floors. For 3/16 inch and wider, use sanded without exception to avoid shrinkage-related defects. Pair with appropriate expansion joints per TCNA guidance to keep the system flexible where it needs to be.

Durability outdoors and underwater

Weather, water, and thermal cycling demand a grout that stays full and stable. Sanded formulations meet that challenge, maintaining joint integrity against expansion, contraction, and scuffing. With proper curing and sealing where specified, sanded grout delivers long service life in demanding environments.

Common Misconceptions

“Sanded grout always scratches tile”

Not always. Dense porcelain and most glazed ceramics tolerate sanded grout without surface damage. The risk is mainly with soft stone and polished finishes. When unsure, perform a small mock-up and evaluate under jobsite lighting before proceeding.

“Unsanded grout is only for walls”

Unsanded can work on floors with very tight joints and delicate surfaces, but it’s not suited to wider joints or heavy traffic. When durability is the priority, move to sanded or, in specialty cases, an epoxy grout.

“Either type is fine for 1/8 inch joints”

Technically true, but context matters. On floors, sanded generally wins for strength. On polished stone walls, unsanded avoids scratching. Let joint width, tile hardness, and location guide the choice.

Matching SGM Products to Use Cases

SGM sanded grout lineup

SGM’s sanded grouts deliver high compressive strength, reduced shrinkage, and broad color coverage—ideal for floors, decks, and submerged settings with joints at or above 1/8 inch. The 32-color palette supports tone-on-tone blends or bold contrast effects while maintaining professional performance.

SGM unsanded grout lineup

For narrow joints and sensitive surfaces, SGM’s unsanded grouts offer a creamy, easy-to-tool body that finishes smooth and even. They’re formulated for strong adhesion, consistent color, and dependable results in vertical applications and fine mosaics.

Choosing by scenario

Floors with 3/16–3/8 inch joints ? sanded. Polished marble shower walls with 1/16–1/8 inch joints ? unsanded. Exterior stone patio with variable joints ? sanded. Glass mosaic waterline with 1/16 inch joints ? unsanded. When the project includes both, split by area and respect the joint-size rules.

Troubleshooting Application Mistakes

Using the wrong grout type

Unsanded in wide joints can slump or crack; sanded on soft stone can scratch. If a mismatch occurs, stop, remove a small test area, and switch product types before continuing. Better yet, plan with a mock-up and confirm under site lighting.

Improper mixing and slaking

Too much water weakens the matrix and washes pigment; too little water hurts workability and packing. Measure liquids, mix mechanically, allow the grout to slake, then remix without adding water. Keep batch sizes consistent to protect color uniformity.

Washing errors and color issues

Overwashing dilutes pigment near the joint face, causing shading or light spots. Use a well-wrung sponge, clean diagonally, and avoid “flood washing.” Control airflow and temperature to prevent rapid drying that can lead to mottling.

Summary Chart and Recommendations

Quick reference

Joint width: less than 1/8 inch ? unsanded; 1/8 inch or more ? sanded (floors favor sanded at 1/8).
Tile type: polished marble, glass, soft stone ? unsanded; porcelain, ceramic, textured stone ? sanded.
Location: vertical decorative, mosaics, tight joints ? unsanded; floors, exterior, submerged, wide joints ? sanded.

Practical takeaways

Let joint width lead, validate against tile hardness, and factor location stresses. When in doubt, build a small mock-up and confirm appearance, cleanability, and scratch resistance before committing. The right match minimizes callbacks and keeps color, joints, and surfaces looking consistent for years.

FAQs About Sanded and Unsanded Grout

Your top questions, answered

Can I mix sanded and unsanded?
No. They’re engineered for different purposes. Mixing compromises strength, texture, and color.

Do I need to seal the grout?
Most cement-based grouts benefit from a compatible sealer to resist stains and ease maintenance. Follow product guidance.

Is unsanded okay for a pool floor?
Generally no. Pool floors need the strength of sanded grout and robust joint packing.

How do I prevent cracking?
Choose the correct grout type, pack joints firmly, follow mix ratios, and include movement joints per TCNA guidelines.

What about 1/8 inch exactly?
Use project context: floors and heavy use ? sanded; delicate wall surfaces ? unsanded. Mock-up if unsure.

Product Reference

Specs, colors, and project planning tools

Explore SGM’s full grout portfolio—sanded and unsanded—in all 32 designer colors, plus data sheets, coverage charts, and best-practice guides. Start here to match performance with design goals and keep your project on schedule:
Visit SGM grout solutions.

Ready to finalize your selection?

Lock in the right grout for your tile, joint size, and location

Bring your tile sample and target joint width, and we’ll help you pinpoint the exact SGM grout—sanded or unsanded—and the color that frames your design. Connect with your local distributor or contact SGM to review submittal documents, get coverage estimates, and schedule delivery. Choose confidently, install efficiently, and hand off a finish that looks intentional and lasts.