For traditional cement grout, sanded products generally suit wider joints, while unsanded products suit narrow joints and some scratch-sensitive finishes. But the bag's stated joint range and tile compatibility decide the job, not that shortcut alone.
The important exception is fine-aggregate grout. Some modern cement products cover both narrow and wide joints. For example, MAPEI Ultracolor Plus FA specifies 1/16-inch to 3/4-inch joints. It isn't traditional unsanded grout. MAPEI product details
Sources checked November 4, 2026. Product ranges below are specific examples, not universal limits. The worked quote uses illustrative USD costs, not a local installation price.
Sanded vs unsanded grout: the quick comparison
| Choice | Useful starting point | Check before buying |
|---|---|---|
| Traditional sanded cement grout | Wider joints within the product's listed range | Joint width, tile finish, and scratch risk |
| Traditional unsanded cement grout | Narrow joints; may suit sensitive polished finishes | Maximum width and tile manufacturer's approval |
| Fine-aggregate cement grout | One product may cover narrow and wide joints | Exact width range, surface compatibility, and working time |
For a concrete comparison, these three manufacturer-listed ranges show where the usual rule stops being enough:
| Example product | Type | Listed joint width |
|---|---|---|
| MAPEI Keracolor S | Sanded cement grout | 1/8 to 5/8 inch |
| MAPEI Keracolor U | Unsanded cement grout | 1/16 to 1/8 inch |
| MAPEI Ultracolor Plus FA | Fine-aggregate cement grout | 1/16 to 3/4 inch |
Sources: Keracolor S, Keracolor U, Ultracolor Plus FA. These examples are for selection guidance, not a brand ranking.
At exactly 1/8 inch, the traditional products overlap. Tile compatibility, location, and the particular product instructions become the deciding factors. Don't use “walls get unsanded, floors get sanded” as the specification.
Start with the tile finish, then check the joint
For polished stone, glass, or another sensitive finish, confirm what the tile manufacturer permits. Aggregate can scratch some surfaces. Unsanded grout is an option for suitable narrow joints, but it isn't an automatic approval for every tile. Custom Building Products identifies its non-sanded grout for narrow joints and polished surfaces that could be scratched by sanded grout. Custom product document
Before grouting the full area, make a small sample with the actual tile, grout color, and cleaning method. Check the surface and finished appearance. Include that sample work in the estimate instead of discovering an incompatible combination halfway through installation.
For example, a polished-stone backsplash with 1/16-inch joints calls for a different compatibility check than a matte porcelain floor with 1/4-inch joints. Neither “backsplash” nor “floor” is enough information to order grout.
Record these five inputs on the takeoff:
- Tile product and finish.
- Actual tile length, width, and thickness.
- Specified joint width and expected grout depth.
- Grout product and color.
- Installation location and the selected system's restrictions.
Fine aggregate changes the familiar rule
If a recommendation says “all joints under 1/8 inch need unsanded grout,” it misses products with finer aggregate. MAPEI specifically identifies Ultracolor Plus FA as suitable down to 1/16 inch. Its published instructions also distinguish it from conventional cement grouts, including its rapid-setting behavior and sealer requirements. MAPEI
That broader width range doesn't remove the tile-compatibility check. It also doesn't make the product interchangeable with epoxy or ready-to-use grout. When a customer or specification names a different grout category, price that exact system and its installation requirements.
For the quote, allow for the crew's actual process: measuring, mixing, application, cleanup, and any return visit. A bag that costs more can still produce a reasonable job total, but don't assume a time saving you haven't established.
Example: how much grout for a 300-square-foot floor?
Area alone isn't enough. Joint width and tile dimensions change the amount of grout required.
The Keracolor S technical sheet estimates 383 sq ft per 25 lb for 12-by-12-by-3/8-inch tile with 1/8-inch joints, versus 191 sq ft with 1/4-inch joints. These are product-specific estimates, not yields for every sanded grout. MAPEI coverage table
For this example, add a separate 10% estimating allowance to the 300-square-foot floor: 300 × 1.10 = 330 sq ft of coverage to purchase.
| Same tile and floor area | 1/8-inch joints | 1/4-inch joints |
|---|---|---|
| Published coverage per 25 lb | 383 sq ft | 191 sq ft |
| Coverage needed with our allowance | 330 sq ft | 330 sq ft |
| Equivalent 25-lb quantities | 330 ÷ 383 = 0.86 | 330 ÷ 191 = 1.73 |
| 25-lb bags to buy, rounded up | 1 | 2 |
| Illustrative cost at $35 per bag | $35 | $70 |
The wider joint doubles the bags purchased in this example. It doesn't establish that the whole tile job costs twice as much. The $35 bag price and 10% allowance are assumptions; use current supplier pricing and a suitable allowance for the layout and crew.
Check whether your chosen calculator already includes overage before adding it again. Irregular tile edges, actual joint depth, waste, and site conditions can change consumption. Keep partial bags and color consistency in mind when deciding the purchase quantity.
Turn the quantity into a useful quote
Here is a simplified grouting-only cost example for the narrower-joint option above. It assumes the tile is already installed and ready for grouting.
| Cost input | Illustrative amount |
|---|---|
| One 25-lb bag | $35 |
| Consumables and protection | $30 |
| Application and cleanup: 6 person-hours at $55 cost/hour | $330 |
| Direct cost | $395 |
| Allocated company overhead | $55 |
| Cost to recover before profit | $450 |
At a 30% margin on that defined cost base, $450 ÷ 0.70 = $642.86, which you might quote as $645 before applicable tax. Six person-hours is a scenario input, not a production benchmark. Use your own labor records for the actual tile, access, and grout.
This example excludes tile setting, grout removal, repairs, waterproofing, movement-joint sealant, and any separate sealing visit. If those are part of the job, add them as line items. Use the flooring cost calculator for the broader project and the markup calculator to check your selling-price calculation.
For an existing tiled area, inspect before quoting a regrout. Removing old grout and dealing with loose or damaged tile are different tasks from grouting a ready surface. Don't copy the new-installation labor allowance into a repair quote.
Showers, sealing, and return-to-service time
Grout is not the shower's waterproofing system. Schluter explains that tile and grout are not inherently waterproof; the assembly needs an appropriate waterproofing system. Choosing sanded instead of unsanded grout doesn't resolve that requirement. Schluter shower systems
Sealing and cure times are product-specific. Don't put “seal all grout” or “shower ready tomorrow” into every estimate. Read the current technical sheet for the selected product, its installation conditions, and the planned use. Separate foot traffic, cleaning, sealing, and water exposure when explaining the handover schedule.
Write the quote so the customer can see what is included. For example:
Grout 300 sq ft of installed porcelain floor tile using the approved product and selected color at the specified joint width. Includes protection, grout application, and cleanup. Tile repairs, existing-grout removal, waterproofing, and separately specified sealant work are excluded. Return-to-service timing follows the selected product's instructions.
Replace “approved product” with the actual product name before approval. The flooring estimate template and scope-of-work guide help keep those details attached to the price.
Common questions
Can I use sanded grout in 1/16-inch joints?
Not if the selected product's minimum is 1/8 inch. A fine-aggregate product expressly approved for 1/16-inch joints may work, subject to tile compatibility. Read the specific product range rather than relying on how the grout feels in the bag.
Is unsanded grout better for shower walls?
Not automatically. Choose by the joint width, tile finish, and product's approved use. The shower's waterproofing is a separate part of the assembly.
Does unsanded grout cost less to install?
There isn't a useful universal answer. Compare the exact material quantity, surface preparation, application and cleanup time, and any return visits. A small difference in bag price can be outweighed by one extra trip.
