A beautiful tile job can be spoiled by the wrong grout. Use a gritty grout beside polished marble and you may scratch the surface; use a grout that isn’t suited to a wide joint and it may crack as it dries. Unsanded grout solves a particular set of problems, especially in narrow joints and around delicate tile—but it isn’t the right choice for every floor, wall, or bathroom.
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What Is Unsanded Grout?
Unsanded grout is grout made without the sand particles found in traditional sanded grout. It’s usually a cement-based powder that you mix with water or a manufacturer-approved additive, though ready-to-use products and other grout types are also available. Always check the specific product label: “unsanded” describes the texture, but it doesn’t tell you everything about where or how the grout can be used.
Without sand, the mixture is smoother and less abrasive. That makes it useful for narrow tile joints and for surfaces that could be scratched by gritty grout. It also tends to feel creamier while you work it into a joint, though some installers find it stickier and less forgiving to clean than sanded grout.
What Is Unsanded Grout Used For?
Narrow grout joints
Unsanded grout is commonly used in narrow joints, often around 1/8 inch wide or less. The exact limit depends on the product, so the package instructions should take priority over a general rule of thumb.
Why does joint size matter? Sand gives grout body and helps it resist shrinkage in wider spaces. In a very narrow joint, those larger particles can make it difficult to pack the grout evenly. Unsanded grout’s fine texture can flow into the gap more easily and leave a smooth, filled joint.
For example, small wall tiles set close together may have joints too narrow for sanded grout to fill neatly. Unsanded grout can be a practical option, provided the tile maker and grout instructions allow it.
Polished or scratch-sensitive tile
Unsanded grout is often chosen for polished marble, limestone, glass, and other surfaces that may be marked by abrasive particles. Since it has no sand, it reduces the risk of scratching the tile while you spread and clean the grout.
That doesn’t mean every unsanded grout is automatically safe for every delicate tile. Grout can still leave residue, and glass tile, natural stone, and specialty finishes vary. Check the tile manufacturer’s recommendations, and test the grout on a spare tile or an inconspicuous area before doing the whole installation.
Some wall tile and detailed surfaces
Unsanded grout can be easier to press into tight joints on walls and around small decorative tiles. Its smooth consistency may also be helpful when working with detailed patterns where grout lines are fine and closely spaced.
However, the surface being vertical doesn’t automatically mean unsanded grout is the correct choice. Joint width, tile material, the product’s approved uses, and exposure to water all matter. A wall made from large tiles with wide joints may call for a grout designed for those joints instead.
Unsanded Grout vs. Sanded Grout
The simplest difference is the texture: sanded grout contains sand, while unsanded grout does not. That difference affects how each product handles, the joints it can fill, and the surfaces it may suit.
| Feature | Unsanded grout | Sanded grout |
|---|---|---|
| Texture | Smooth and fine | Gritty, with sand particles |
| Common use | Narrow joints, often around 1/8 inch or less, depending on the product | Wider joints, when allowed by the product instructions |
| Delicate surfaces | Often considered for polished or scratch-sensitive tile; test first | Can scratch some polished or delicate surfaces |
| Potential drawback | May shrink or crack if used in joints that are too wide | May be difficult to pack into very narrow joints |
Neither type is universally stronger or better. The right choice depends on the tile, joint width, and grout manufacturer’s specifications. Some newer grouts are formulated to cover a wider range of joint sizes, so don’t rely on the word “sanded” or “unsanded” alone when the product label gives more specific guidance.
When Should You Avoid Unsanded Grout?
Unsanded grout is often a poor fit for joints wider than the product allows. In a wide gap, it can shrink as it cures, which may lead to cracks, low spots, or grout that pulls away from the tile edges. A sanded grout or a grout specifically rated for that joint width may be a better choice.
It may also be unsuitable for floors or other areas that see heavy movement and wear if the product isn’t rated for that use. Floors can place more stress on grout joints than a quiet bathroom wall. Follow the grout and tile manufacturers’ instructions, especially for large-format tile, stone, and installations over heated floors.
Don’t use grout to fill movement joints or changes of plane, such as an inside corner, a wall-to-floor seam, or the edge of a tub. Those areas can move slightly. A compatible flexible sealant, often a tile-grade silicone or another product approved for the installation, is generally used there instead. The movement-joint requirements for the project and product should guide the details.
Can You Use Unsanded Grout in a Shower?
Sometimes. Unsanded grout may be suitable for a shower if the grout is approved for that application and the joint size and tile material are compatible. Read the label rather than assuming that a grout is shower-safe just because it is used between tiles.
Grout itself is not a substitute for a waterproofing system. Water can pass through cement-based grout, so a shower needs properly installed waterproofing behind or beneath the tile, along with correctly treated corners and penetrations. Sealer can help reduce staining and water absorption for some cement-based grouts, but it doesn’t turn the tiled surface into a waterproof barrier.
How to Choose and Apply Unsanded Grout
Check the tile and joint first
Measure the joint width and look up the grout manufacturer’s approved range. Then check the tile maker’s guidance, especially if you’re working with polished stone, glass, metal, or a specialty finish. If either manufacturer recommends a different grout type, take that seriously.
Prepare and mix carefully
Make sure the tile joints are clean and free of spacers, dust, and excess setting material. Mix the grout exactly as directed, using the stated amount of water or additive. Adding extra water to make the grout easier to spread can weaken the finished grout or affect its color.
Many cement-based grouts need a short rest after mixing, followed by another brief mix. This is sometimes called slaking, but the timing varies by product. Don’t guess: follow the package instructions and mix only as much as you can apply within the stated working time.
Pack the joints and clean without over-washing
Use a grout float or the tool recommended by the manufacturer to press grout diagonally across the joints. This helps push it into the gaps rather than dragging it back out. Remove excess grout from the tile face with the float, then clean with a damp sponge at the time and in the manner the product specifies.
Use a well-wrung sponge and light passes. Too much water or repeated scrubbing can pull grout out of the joints, leave uneven color, or create a weak surface. Once the grout has cured for the required time, apply sealer only if the grout instructions call for it. Some grout products don’t need sealing, while others benefit from it.
Common Mistakes to Avoid
- Choosing by habit: The grout that worked in one room may not suit a different tile or joint width.
- Ignoring the product range: Joint-size limits vary, so check the label instead of treating 1/8 inch as a universal cutoff.
- Skipping a test: A small test can reveal scratching, staining, or difficult cleanup before the whole surface is grouted.
- Adding too much water: Follow the specified mixing ratio to avoid performance and color problems.
- Grouting corners that need flexibility: Use the appropriate movement-joint material where the installation requires it.
Read more related posts:
- 10 ways to restore discolored bathroom tile grout fresh look
- 10 common shower tile grout cracking causes their solutions
- How to clean bathroom floor grout without a brush? easily
Frequently Asked Questions
Is unsanded grout better than sanded grout?
Not in every situation. Unsanded grout is often better for narrow joints and scratch-sensitive surfaces, while sanded grout is often suited to wider joints. The tile, joint width, and product instructions determine the best option.
Can unsanded grout crack?
Yes. It may crack or shrink if used in joints wider than its approved range, or if the installation or mixing doesn’t follow the manufacturer’s directions. Choosing grout rated for the joint is the best place to start.
Does unsanded grout need to be sealed?
Some cement-based unsanded grouts benefit from sealing, while other products don’t require it. Check the label. Sealer may help resist stains, but it doesn’t waterproof a shower or replace a proper waterproofing system.
Can I use unsanded grout on polished marble?
It’s often considered because it lacks abrasive sand, but test it first and follow the stone and grout manufacturers’ instructions. Natural stone can be sensitive to grout residue and cleaning products as well as scratches.
Conclusion
Unsanded grout is mainly used for narrow joints and tile surfaces that could be scratched by gritty grout. Its smooth texture helps it fill fine gaps, but it can shrink or crack when used beyond its approved joint width. Check the tile and grout instructions, test delicate surfaces, and use the right flexible sealant at movement joints. Those few checks can save you from a costly repair later.
