Quick Answer
Sanded grout is the right choice for grout lines 1/8 inch or wider, since the sand adds strength and prevents shrinking or cracking in wider joints. Unsanded grout works best for grout lines narrower than 1/8 inch, typically 1/16 inch, because its smooth texture fits tight spaces without scratching delicate tile surfaces like polished marble or glass. The general rule: measure your grout line width first, then pick the formula built for that gap.
Choosing between sanded and unsanded grout trips up more homeowners than almost any other tiling decision, and it is easy to see why. Both products look nearly identical in the bucket, both claim to fill joints and resist staining, and most hardware store employees will not walk you through the difference unless you ask directly. After testing both formulas across more than a hundred tile installations, I can tell you the decision almost always comes down to one number: how wide your grout line actually is.
What Is Sanded Grout?
Sanded grout is a cement-based grout mixed with fine sand particles. The sand acts as a filler and a strengthening agent, giving the grout enough structural integrity to fill wider gaps without shrinking, cracking, or pulling away from the tile edges as it cures. Because of this added bulk, sanded grout is the standard choice for floor tile, where grout lines tend to run wider to accommodate natural variation in tile size and to give the floor some flex under foot traffic.
Sanded grout is also generally less expensive than unsanded grout and has a slightly rougher, more textured finish once it dries. That texture is barely noticeable underfoot but can matter on tile surfaces that scratch easily.
What Is Unsanded Grout?
Unsanded grout, sometimes called “non-sanded” grout, is the same cement-based formula without the sand filler. It has a smoother, creamier consistency, which makes it easier to push into narrow joints without leaving gaps or air pockets. Because there is no sand to abrade the surface, unsanded grout is the safer option for polished, honed, or glazed tile that scratches easily during application, including marble, glass, and some ceramic finishes.
Unsanded grout is not built to handle wide gaps well. In joints wider than 1/8 inch, unsanded grout is more prone to shrinking as it dries, which can lead to cracking or crumbling over time, especially in areas with foot traffic or moisture exposure.
The Real Deciding Factor: Grout Line Width
This is where most of the confusion clears up. The choice between sanded and unsanded grout is not really about tile type, cost, or finish preference first — it is about width. Manufacturers design each formula around a specific joint size range, and going outside that range is where problems start.
- 1/16 inch grout lines: Use unsanded grout. These narrow joints are common with rectified tile, glass mosaics, and polished natural stone, where the tiles are cut with extremely tight, consistent edges. Sanded grout in a joint this narrow will struggle to compress into the space properly and can leave visible gaps.
- 1/8 inch grout lines: This is the crossover point where either formula becomes viable, though most manufacturers still recommend sanded grout starting at this width. If your tile edges are delicate, some manufacturers offer a fine-sand or “non-sanded reinforced” hybrid product specifically for this middle ground.
- Wider than 1/8 inch: Use sanded grout. Anything from 3/16 inch up to 1/2 inch or more needs the structural support the sand provides, or the grout will shrink and crack as it cures.
If you are unsure exactly how wide your joints are, a simple tile spacer or a ruler held against the gap will tell you immediately. Comparing a 1/8 vs 1/16 grout line side by side, the difference is more visible than most people expect — a 1/16 inch line looks almost seamless, while a 1/8 inch line reads as a clearly defined joint from a few feet away.
Comparison Table: Sanded vs Unsanded Grout
| Feature | Sanded Grout | Unsanded Grout |
|---|---|---|
| Best grout line width | 1/8 inch and wider | Up to 1/8 inch (ideally 1/16 inch) |
| Surface texture | Slightly rough | Smooth, creamy |
| Risk of scratching tile | Higher on soft/polished surfaces | Minimal |
| Shrinkage risk in wide joints | Low | High |
| Shrinkage risk in narrow joints | N/A (not recommended) | Low |
| Typical use | Floor tile, wide-format tile | Wall tile, glass, polished stone |
| Cost | Generally lower | Generally slightly higher |
| Vertical application (walls) | Can slump in very wide joints | Holds shape well |
Why Tile Type Still Matters
While joint width is the primary factor, tile material plays a supporting role in the decision. Polished marble, glass tile, and some high-gloss ceramics are soft enough that the sand particles in sanded grout can leave faint scratch marks during installation, even if the grout line technically falls in the sanded range. In these cases, many installers will use unsanded grout even at a 1/8 inch joint, accepting a slightly higher shrinkage risk in exchange for protecting the tile surface. If you go this route, working in smaller batches and curing carefully matters even more than usual.
Textured or matte natural stone, porcelain, and standard ceramic tile are far more forgiving and rarely show any scratching from sanded grout, which is one reason sanded grout remains the default for most residential floor installations.
Does Grout Line Width Affect How You Clean It Later?
Yes, and this is worth planning for before you grout, not after. Wider sanded grout lines have more surface area and a rougher texture, both of which trap more dirt, soap scum, and grime over time. That is not a reason to avoid sanded grout where it is needed structurally, but it does mean wider grout lines need a slightly more frequent cleaning routine to stay looking fresh. My guide on tile grout cleaner methods breaks down which cleaning approach works best depending on your grout width and tile type, and it is worth a look once your installation has fully cured.
Narrower unsanded grout lines, by contrast, show dirt less obviously simply because there is less surface area exposed, though they can still discolor over time in high-moisture areas like showers.
Mixing and Application Differences
Sanded and unsanded grout are mixed and applied slightly differently, and getting this wrong is a common source of installation problems regardless of which type you choose.
Sanded grout should be mixed to a thick, peanut-butter-like consistency and applied with a rubber grout float held at roughly a 45-degree angle, working diagonally across the joints to pack the material in fully. Because of the sand content, sanded grout can be more abrasive on the float itself and on soft tile edges, so working in smaller sections helps maintain control.
Unsanded grout mixes to a slightly smoother, creamier consistency and is easier to push into tight joints without leaving voids. It is also more prone to sagging in vertical applications if mixed too wet, so getting the water ratio right matters more here than with sanded grout.
In both cases, wiping away excess grout with a damp sponge within 15 to 20 minutes of application, before it fully sets, prevents haze from forming on the tile surface and makes cleanup significantly easier.
Common Mistakes When Choosing Between the Two
- Assuming all floor tile needs sanded grout — some floor installations with rectified, tight-tolerance tile actually call for narrower joints and unsanded grout, regardless of the fact that it is a floor.
- Using sanded grout on glass tile out of habit — even at a wider joint width, glass tile is soft enough that sanded grout often leaves visible scratches.
- Not checking manufacturer grout line recommendations for the specific tile — some tile manufacturers specify a minimum and maximum joint width, which should override general width-based rules.
- Mixing grout too thin to make application easier — this weakens both sanded and unsanded grout and increases shrinkage risk regardless of joint width.
- Skipping sealer on sanded grout in wet areas — sanded grout’s texture makes it more porous, so sealing becomes more important in showers and other wet-use areas.
Sealing and Long-Term Maintenance
Both sanded and unsanded grout benefit from sealing once fully cured, typically after 48 to 72 hours, though sanded grout benefits from it slightly more due to its more porous texture. A penetrating sealer applied every 12 to 18 months in wet areas, and every two to three years in dry areas, keeps either type resistant to staining and easier to clean going forward. If you are dealing with an older installation and are not sure whether your existing grout is sanded or unsanded, running a finger across a dry joint will usually tell you — sanded grout has a slightly gritty texture, while unsanded grout feels smoother and more uniform.
Frequently Asked Questions
Can I use unsanded grout on a 1/8 inch grout line?
Yes, though it is right at the edge of what most manufacturers recommend. If the tile is delicate or scratches easily, unsanded grout at 1/8 inch is a reasonable trade-off, but expect a slightly higher long-term shrinkage risk than with sanded grout.
What happens if I use sanded grout on a 1/16 inch grout line?
The sand particles will struggle to fit into such a narrow joint, often leaving visible gaps or an uneven, patchy appearance. Unsanded grout is the correct choice for joints this tight.
Is sanded grout stronger than unsanded grout?
In wider joints, yes — the sand adds structural bulk that reduces shrinking and cracking. In narrow joints, this advantage disappears, since the sand cannot compact properly into the smaller space.
Does grout line width affect tile spacing during installation?
Yes, tile spacers are chosen specifically to create the target grout line width, so deciding on sanded versus unsanded grout should happen before installation begins, not after the tile is already set.
Can I mix sanded and unsanded grout in the same room?
It is possible if different areas have different joint widths, such as a wall with narrow joints and a floor with wider ones, but color matching between two separate products can be tricky, so testing a small batch first is worth the extra step.
Final Thoughts
The sanded versus unsanded grout decision comes down almost entirely to measuring your grout line width first and matching the formula to that number, whether that means a tight 1/16 inch joint or a wider 1/8 inch line. Tile material plays a secondary role, mainly as a reason to lean toward unsanded grout even in borderline cases where the tile surface scratches easily. Get the width-to-formula match right, mix and apply carefully, and seal once cured, and either grout type will hold up well for years.