Quick Answer
Sanded grout generally suits wider joints; unsanded grout suits narrow joints and surfaces that sand could scratch. For traditional cement grouts, 1/8 inch is the familiar dividing point. Check the named product before choosing: some modern grouts containing fine aggregate also work at 1/16 inch. The joint width, tile finish and approved use area must all match the same product.
What Sand Changes in Grout
Sanded cement grout contains sand particles that give the mixture body. This helps it fill wider spaces with less shrinkage as it hardens. Its finished surface usually shows more grain than a traditional unsanded grout. Unsanded, also called non-sanded, has a smoother texture and is often chosen for narrow joints or delicate tile faces.
The distinction describes the grout mixture. It does not mean that the tile has been sanded, and it does not tell you the complete performance of the product. Cement type, polymers and aggregate size also vary. A modern fine-aggregate grout can therefore handle a joint that would be too narrow for a different sanded formula.
The Tile Council of North America's grout FAQ explains the traditional 1/8-inch division. Use it to understand the two categories, then read the product's permitted range. The examples below show why the name on the bag matters.
Which Grout Fits Your Joint Width?
First establish the joint required by the tile and layout. Choosing a grout that fits a very narrow joint does not establish that the tile itself can be installed at that spacing. Our grout line size chart explains how tile variation, edges and layout affect that earlier decision.
Once the spacing is set, compare the full range of joints on the job with the grout's stated limits. For irregular edges or mosaics, check the wider spaces as well as the narrow ones.
| Named product | Formulation | Joint-width reference | What still needs checking |
|---|---|---|---|
| SikaTile-800 Unsanded | Unsanded cement grout | 1/16–1/8 in | Exact tile, use area and installation instructions |
| Polyblend Plus Sanded | Sanded cement grout | 1/8–1/2 in | Potential scratching on sensitive surfaces |
| Prism Ultimate Performance | Cement grout with fine sand and recycled glass aggregate | 1/16–1/2 in in CUSTOM's coverage chart | Surface test and rapid-setting work sequence |
| Fusion Pro | Ready-to-use sanded grout | 1/16–1/2 in | Drying conditions and restrictions on water exposure |
The inch limits above follow the named US product documents. Approximate equivalents are 1/16 in = 1.6 mm, 1/8 in = 3.2 mm and 1/2 in = 12.7 mm. Manufacturers may round their metric labels differently; follow the instructions supplied for your market. These ranges describe grout compatibility, not a recommended spacing for every tile.
At 1/8 inch, the ranges can overlap
Suppose a tile installation has approved 1/8-inch joints. Both SikaTile-800 Unsanded and Polyblend Plus Sanded pass the width check in this table. That leaves the surface, exposure and desired texture to resolve. A polished tile vulnerable to aggregate scratching changes the choice even though the joint width stays the same.
Now suppose the approved joint is 1/16 inch. Polyblend Plus Sanded falls outside its stated range, but Prism's chart still includes that width. The conclusion is specific: a narrow joint can accept a suitable fine-aggregate product. It does not make every sanded grout suitable for narrow joints.
Glass, Polished Stone and Scratch-Sensitive Finishes
Scratching can happen while the float and cleaning sponge move grout across the tile face. CUSTOM warns that the aggregate in Polyblend Plus Sanded can damage some ceramic, glass, metal, marble and stone tiles. Its Polyblend Plus Non-Sanded technical sheet identifies highly glazed or polished surfaces as an intended use, with joints up to 1/8 inch.
A small test panel is useful because the finish is what the grout actually touches. Two tiles described as porcelain may have different glazes or polished surfaces. A broad material name cannot show how either will react during grouting and cleanup.
Use spare pieces of the actual tile and the proposed grout. Include the intended joint width, any specified pre-treatment, the float and the cleanup method. Leave one clean, untreated piece beside the panel for comparison. After the panel dries, view it under side lighting and ordinary room lighting. Look for scratches, a dulled reflection, pigment lodged in texture and a persistent film. Also inspect whether the joint is full and whether its texture is acceptable.
If the finish is damaged, stop using that combination. A surface that needs unsanded grout may still have joints wider than the available unsanded product permits. Ask the tile and grout manufacturers for a compatible alternative; exceeding the width limit does not solve the surface problem.
Can Both Types Be Used on Floors and Shower Walls?
Yes, when the particular product permits it. Polyblend Plus Non-Sanded lists floor and wall installations, including showers. Polyblend Plus Sanded also lists walls and showers. “Unsanded for walls, sanded for floors” leaves out the joint and finish conditions that determine whether those uses work.
For a backsplash, narrow joints and a delicate glaze may favour an unsanded product. A wider-jointed wall can instead suit an approved sanded product. On a floor, the grout still has to fit the joints and withstand the stated use, but the word “floor” does not automatically rule out every unsanded formula.
In a shower, separate ordinary field joints from the waterproofing and movement details. LATICRETE's grout instructions explain that grout does not replace a required waterproofing membrane. At changes of plane and movement joints, follow the system's specified sealant or movement detail. Both Polyblend sheets exclude their grout from those locations.
Shower approval also does not establish approval for a swimming pool or steam room. Read those uses separately on the selected product sheet. Water exposure and the time allowed before use can be quite different.
Fine-Aggregate, Epoxy and Ready-to-Use Grouts
These names describe different properties, so they are not interchangeable alternatives to “sanded.” Fine aggregate describes the filler. Epoxy describes the binder. Ready-to-use describes how the product is supplied. A grout can have more than one of these characteristics.
Fine aggregate can extend the useful width range
Prism combines fine sand and lightweight recycled glass in a cement-based formula. That makes it a useful example of a product spanning narrow and wider joints. Its technical sheet still carries a scratch warning. The smaller aggregate does not remove the need to test sensitive tile.
Epoxy can still contain sand
LATICRETE's epoxy grout FAQ describes epoxy resin with coloured sand filler and states that its epoxy grouts contain sand. It also identifies their stain and chemical resistance and says they do not require sealing. Those benefits can matter in demanding use areas, but “epoxy” does not mean a smooth, sand-free product.
Compare the exact epoxy's surface limitations, exposure approvals, mixing sequence and cleanup instructions. Do not select it solely to avoid the word “sanded” on a cement-grout bag.
Ready-to-use products have their own drying requirements
Fusion Pro is supplied ready to use and is itself sanded. Its current technical sheet permits shower walls and floors but excludes steam rooms and submerged applications. It cures by evaporation, so damp setting materials, poor ventilation and early water exposure can affect the result.
This is why a general verdict that all premixed grout is suitable—or unsuitable—for showers is unhelpful. Match the exact product to the shower and allow its required drying conditions.
Compare Curing, Sealing and the Installed Sample
Ready for foot traffic is different from ready for water. Prism is described as walkable in four hours, while its technical sheet allows intermittent water exposure after three days. Fusion Pro specifies seven days before intermittent water exposure at 70°F (21°C) and 50% relative humidity; lower temperatures and higher humidity slow its cure.
For another example, SikaTile-800 Unsanded specifies 24–48 hours before residential shower use, while identifying 28 days as full cure. These are different milestones for different formulations. Schedule the job using the exposure that comes next and the instructions for the complete tile assembly.
The water and waiting times during mixing matter too. Polyblend Plus Non-Sanded lists a pot life of 1–2 hours. A product's pot life is the usable time in the container; it is not permission to leave residue on tile for that long. Follow the separate application and cleaning sequence. Adding water to stiffening grout can change colour and weaken the result.
Sealing also needs a product-specific answer. The current Polyblend Plus sanded and non-sanded sheets describe a penetrating sealer as optional extra protection. Prism and the LATICRETE epoxy products discussed above do not require a grout sealer. A tile may have its own sealing requirement, which must also be compatible with the grout.
When comparing cost, obtain the local price for the exact product and colour, then use its coverage chart with your tile dimensions, joint width and depth. Compare the whole packages needed for the area, together with any specified sealer and the installation work. A cheaper bag can cover a different area or require a different process.
Keep the approved sample with the tile and grout product names, colour, joint width and cleanup method recorded. It gives the installer and buyer a shared reference for appearance. If the project is still selecting sintered stone, establish the actual finish and module to include in that panel.
Choosing Sintered Stone for Your Project?
Share the application, planned module size and finish reference. Funtek can help organize material options and sample information for your project.