A grout joint may look like a tiny detail, but choose the wrong grout and you can end up with cracked lines, scratched tile, or a finish that’s much harder to clean than it should be. Unsanded grout is often the right choice for narrow joints and delicate tile—but it isn’t right for every project. Here’s how it works, where it belongs, and what to check before you use it.
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What Unsanded Grout Is
Unsanded grout is a cement-based tile grout made without the coarse sand found in traditional sanded grout. Instead, it uses fine particles and binders to fill the spaces between tiles. That finer texture helps it fit into narrow grout joints and makes it less abrasive against many smooth or delicate tile surfaces.
“Unsanded” doesn’t mean the grout has no minerals or other ingredients. The exact formula varies by product and may include polymers or other additives to improve bonding, flexibility, or water resistance. Always read the product label: the grout’s stated joint-size range and installation instructions matter more than the name alone.
Why the Grout Joint Size Matters
Grout has to fill the joint and stay there as it hardens. The width of that joint affects how well a particular formula can do the job. Unsanded grout is commonly used in narrow joints, often around 1/8 inch wide or less, though product directions can vary.
In a wider space, unsanded grout may shrink as it dries or fail to hold its shape well. That can leave low spots, cracks, or grout that breaks away from the tile edges. Sanded grout contains larger grains that help it fill and support wider joints. Some newer products cover a wider range of joint sizes, so don’t rely on a one-size-fits-all rule—check the manufacturer’s specifications.
Where Unsanded Grout Is Commonly Used
Narrow grout joints
When tiles are set close together, fine-textured grout can pack into the gap without the larger grains of sand. This makes unsanded grout a common option for tight joints on walls, backsplashes, and other tile installations. A narrow joint still needs to be clean and deep enough for the grout to bond properly; grout won’t perform well if thinset or debris fills most of the space.
Delicate or easily scratched tile
Coarse sand can scratch some polished or soft tile surfaces during grouting. Unsanded grout is less abrasive, so installers often consider it for polished marble, some limestone, and certain glass tiles. That doesn’t make it automatically safe for every surface. Tile finishes differ, and even fine grout or cleaning tools can leave marks.
Before grouting the whole area, test the grout and cleanup method on a spare tile or an inconspicuous spot. Follow the tile and grout manufacturers’ advice, especially with natural stone and specialty glass.
Vertical tile surfaces
Because unsanded grout is usually used in smaller joints, it can be easier to work into narrow spaces on a wall. The right choice still depends on the tile, joint width, and product instructions. Grout type alone won’t prevent a poor result if the mix is too wet or the joints aren’t prepared correctly.
Unsanded Grout Compared With Other Options
| Grout type | Typical use | Main advantage | What to watch for |
|---|---|---|---|
| Unsanded cement grout | Narrow joints and some delicate tile surfaces | Fine texture; less abrasive than coarse sanded grout | May shrink or crack in joints wider than its product rating |
| Sanded cement grout | Wider joints, when allowed by the product and tile | Sand helps support grout in a wider space | May scratch some polished or soft surfaces |
| Epoxy grout | Projects where the selected product’s performance and tile compatibility suit the job | Often resists stains and water better than standard cement grout | Can be harder to install and clean; follow its specific instructions |
This is a general comparison, not a substitute for the product label. “Epoxy” is a different grout category, not simply a more waterproof version of unsanded cement grout. Its working time, cleanup, and compatibility requirements can be quite different.
Benefits and Limitations
Benefits
- Works well in narrow joints: Its fine texture can fill tight spaces where a coarser grout may be difficult to pack neatly.
- Less abrasive: It may be a better candidate for tile that could be scratched by sand, provided the tile maker approves it.
- Can give a smooth finish: When mixed and cleaned properly, it leaves a fine, even-looking joint.
- Useful for many wall installations: Narrow wall joints are a common setting for unsanded grout, though the product’s directions still decide.
Limitations
- Not suited to every joint width: In a joint that’s too wide, it can shrink, crack, or become weak.
- Not automatically waterproof: Cement-based unsanded grout can absorb moisture. It doesn’t replace waterproofing behind tile in a shower or other wet area.
- May need sealing: Many cement grouts benefit from a compatible grout sealer, but requirements differ. Check the grout label and wait for the specified curing time before sealing.
- Can still stain or discolor: Water ratio, dirty tools, uneven drying, and harsh cleaners can affect the finished color.
How to Use Unsanded Grout Properly
1. Check the tile and grout instructions
Start by confirming that the grout is approved for your tile type and joint width. Then check whether the tile needs special handling. Natural stone may need protection from pigment or residue, while glass tile may have its own grout recommendations.
2. Prepare the joints
Remove spacers and clear out thinset, dust, and loose material from the joints. If the spaces are partly blocked, grout can’t fill them evenly. Don’t gouge the tile edges while cleaning, and make sure the thinset has cured for the time specified by its manufacturer.
3. Mix carefully
Measure water according to the package rather than estimating. Too much water can weaken cement grout and contribute to uneven color or shrinkage. Mix until the grout is smooth, let it rest for the stated slake time if the instructions call for one, then remix. Don’t add extra water later just because the mix has started to stiffen.
4. Pack the grout into the joints
Use a grout float to press grout across the tile and firmly into the gaps. Work at an angle to the joints so the float fills them instead of dragging grout back out. Remove excess from the tile face with the float, while taking care not to scoop grout out of the joints.
5. Clean at the right time
Wait until the grout has firmed up enough that a damp sponge won’t pull it from the joints. Then wipe gently with a well-wrung sponge, rinsing it often. Flooding the surface or repeatedly scrubbing the same spot can wash cement and pigment out of the grout, leaving a weak or blotchy finish. Follow the package’s timing; temperature and humidity can change how quickly grout firms up.
6. Let it cure and maintain it
Keep the installation protected for the curing period stated by the manufacturer. Don’t assume a grout line is ready for heavy use as soon as it feels dry. If the grout is cement-based and the product recommends sealing, apply a compatible sealer only after the grout has cured sufficiently.
Common Mistakes to Avoid
- Choosing by habit: A grout that worked in one room may not suit a different tile or joint width.
- Using it in an oversized joint: Check the product’s maximum joint width to reduce the risk of shrinkage and cracking.
- Skipping a scratch test: “Less abrasive” doesn’t mean harmless to every polished surface.
- Adding too much water: Loose grout is easier to spread, but excess water can compromise the finish and strength.
- Treating grout as waterproofing: In wet areas, the waterproof layer belongs behind the tile system. Grout alone can’t protect the structure from water.
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?
Neither is universally better. Unsanded grout is often suited to narrow joints and some scratch-sensitive tile, while sanded grout is commonly chosen for wider joints. The right answer depends on the joint size, tile surface, and product instructions.
Can I use unsanded grout on a shower wall?
Often, yes, if the tile and grout product are compatible and the joint width is within the product’s range. But grout is not a substitute for a properly installed waterproofing system behind the tile.
Does unsanded grout need to be sealed?
Many cement-based grouts can benefit from sealing, but the need and timing depend on the specific product. Check the label and use a sealer approved for that grout and tile.
Can unsanded grout crack?
Yes. Cracking can happen if it’s used in joints wider than its rating, mixed with too much water, or installed over a surface that moves. If a crack appears, identify the cause before replacing the grout, or the problem may return.
Can I use it with glass tile or polished stone?
Possibly, but check the tile manufacturer’s guidance and test a spare piece first. Different glass and stone finishes respond differently to grout and cleanup, even when the grout has a fine texture.
Conclusion
Unsanded grout is a fine-textured cement grout commonly used for narrow joints and, when approved, tile surfaces that may be scratched by coarser grout. Its success comes down to matching it to the joint and tile, mixing it as directed, and cleaning it without washing the grout out. Check the product label before you begin, and remember that grout—sanded or unsanded—is not a waterproofing system.
