Grout is the last thing that goes into a tile job and the first thing people notice. Even, full grout lines make a careful install look professional; patchy color, pinholes and haze make a flat floor look sloppy. The good news is that grouting is a repeatable process. This guide explains how to grout tile step by step: when to start, which grout fits your grout lines, how to apply grout with a float, how to clean it, where to use caulk instead, and when you can seal. The steps follow published grout manufacturer instructions; your grout’s own data sheet always has the final word.
How do you grout tile, step by step?
To grout tile: let the mortar cure, remove spacers or clip tops, clean the joints, mix the grout, pack it into the joints with a rubber float held at about 45 degrees, scrape off the excess with the float edge, sponge the surface with a damp sponge, remove haze, caulk changes of plane, then let it cure before sealing.
- Wait for the mortar. Check the setting mortar’s cure time before grouting.
- Clear the joints. Remove spacers and snap off leveling clip tops; clean out mortar squeeze-out and debris.
- Pick the grout. Match grout type to joint width and tile.
- Mix. Follow the bag for water, mixing speed and any slake time.
- Spread and pack. Fill the joints completely, working diagonally.
- Strike off. Remove excess grout from the tile face with the float edge.
- Sponge. Smooth the joints and clean the face with a damp sponge.
- Remove haze. Buff off the dry film once the grout has firmed.
- Caulk. Use flexible sealant at corners, perimeters and changes of plane.
- Cure and seal. Protect the floor while it cures and seal only when the grout maker allows.
When can you grout after laying tile?
Grout once the setting mortar has cured enough to hold the tile firmly. CUSTOM Building Products, for example, calls for setting material to cure a minimum of 24 to 48 hours before cement grout is applied, unless a rapid-setting mortar is used. Your mortar bag gives the exact time.
Grouting too early can shift tiles and trap moisture that discolors the grout. Before you start, remove every spacer and leveling clip top. Both LATICRETE and CUSTOM instruct installers to remove spacers and debris and to have joints uniform in depth and width. If you used a leveling system, follow how to remove tile leveling clips first; for plain spacers, see how to remove tile spacers. Then vacuum the joints. If you are still setting the tile, start with porcelain tile installation, step by step.
Which grout do you need for your grout lines?
The width of your grout lines decides the grout type. Unsanded grout is for narrow joints, generally 1/8 inch or less; sanded grout is for wider joints, and some sanded grouts are rated down to 1/16 inch while others start at 1/8 inch. Always check the joint range printed on the bag.
| Grout type | Typical joint range | Notes |
|---|---|---|
| Unsanded (non-sanded) cement grout | 1/8 inch or less | For soft or polished stone and soft glazed tile; LATICRETE limits unsanded grout to 1/8 inch joints |
| Sanded cement grout | From 1/16 or 1/8 inch up, per product | LATICRETE sanded grout: 1/16 inch and wider; CUSTOM Polyblend Plus Sanded: 1/8 to 1/2 inch |
| Epoxy grout | Per product data sheet | Stain resistant; LATICRETE notes its epoxy grouts do not require a sealer |
| Pre-mixed grout | Per product data sheet | Ready to use; follow the specific instructions on the pail |
For ceramic and porcelain tile from 12×12 to large format, a 1/8 inch joint is common when you want a narrow but visible grout line. Comparing joint widths? Read 1/16 vs 1/8 grout line and check the grout joint size chart.
How do you apply grout with a float?
Hold a rubber grout float at about a 45 degree angle and push grout diagonally across the joints until they are completely full. Then turn the float nearly upright, at about 90 degrees, and drag its edge diagonally across the tile to strike off the excess without pulling grout out of the joints.
Those angles come straight from the CUSTOM Polyblend Plus instructions, and LATICRETE gives the same advice in plain words: mix the grout as stiff as possible without losing workability and use a sharp rubber float to pack it fully into the joints. Working diagonally keeps the float from dipping into the joints. Spread only as much as you can clean in time; CUSTOM says that at 70 degrees F you should not spread more than you can clean within 30 minutes of the grout firming, and heat shortens that window.
Mixing matters as much as spreading. Some grouts call for slaking: CUSTOM’s sanded grout is mixed, left to stand for 5 minutes, then remixed. Others, such as ARDEX FL, need no slake time. Do not add water to stiffening grout; CUSTOM warns it can weaken the grout and cause color variation, shrinkage, cracks and pinholes. If you use more than one bag, LATICRETE recommends matching batch numbers or dry-mixing the powder together first.
How do you clean grout off tile?
Once the grout firms in the joints, wipe the surface with a damp, well-wrung sponge, shaping the joints as you go and rinsing the sponge often. Use as little water as possible. When the grout has hardened, buff off the remaining haze with a barely damp sponge or a clean cloth.
Too much water is the most common grouting mistake. LATICRETE warns that excess water can wash pigment out of cement grout and leave a lighter shade. CUSTOM’s instructions say haze can be removed after 3 hours with cheesecloth or a wrung-out sponge, and give options for persistent haze days later. Keep your technique the same across the whole floor so the color stays consistent. Flat, flush tile edges help too: lippage creates ridges where grout and haze collect, which is one more reason to set tile with a tile leveling system and leveling clips sized to your grout joint.
Where should you use caulk instead of grout?
Use a flexible sealant, not grout, where tile meets walls, tubs, curbs, other materials and inside corners, and at every change of plane and movement joint. Grout is rigid and cracks at those points when the building moves.
LATICRETE recommends flexible sealant wherever tile abuts restraining surfaces and at all changes of plane, and points to TCNA detail EJ171 for movement joint layout. CUSTOM states its sanded grout is not for movement joints or changes of plane. In a shower, that means the corners and the joint between wall and floor get sealant in a matching color.
How long before you can seal grout?
Wait for the grout to cure as its maker directs before sealing. LATICRETE recommends that its cement grouts cure at least 72 hours at 70 degrees F before applying a sealer, and notes that its epoxy grouts do not require one. Light foot traffic usually comes sooner.
CUSTOM, for its sanded grout, says not to open the floor to foot traffic before 16 hours of cure, to protect it from heavy traffic until fully cured, and to keep the space above 50 degrees F for at least 72 hours. Check the sealer label as well, since some sealers need a longer wait.
Frequently asked questions
Do you remove tile spacers before grouting?
Yes. Grout makers call for joints free of spacers and debris so the grout can fill the full depth.
Can you grout over leveling clip bases?
Yes. After the clip tops snap off, the bases stay under the tile and below the joint, so grout fills over them.
How long does grout take to dry?
It depends on the grout and the room. Follow the cure and foot traffic times on the bag; cool, damp rooms cure more slowly.
Should you seal tile before grouting?
For porous, textured or unglazed tile, grout makers suggest a grout release or pre-sealer to prevent staining. Test on a spare tile.
Key terms
- Grout float: a flat rubber-faced tool used to push grout into joints and strike off the excess.
- Slaking: letting mixed grout stand for a few minutes before remixing, when the maker calls for it.
- Strike off: removing excess grout from the tile face with the float edge held nearly upright.
- Joint tooling: shaping the surface of the grout joints with a sponge or tool so they are smooth and even.
- Grout release: a temporary coating applied to porous tile before grouting so grout cleans off easily.
- Flexible sealant: caulk or sealant used instead of grout at corners, perimeters and movement joints.
- Change of plane: where one tiled surface meets another at an angle, such as a wall corner or wall-to-floor joint.
- Batch number: the production code on a grout bag; matching it avoids shade differences between bags.
Sources
- CUSTOM Building Products, Polyblend Plus Sanded Grout data sheet (cure before grouting, float angles, slaking, haze, cure)
- LATICRETE, cement grout FAQ (sanded vs unsanded, cleaning, sealing, flexible sealant)
- LATICRETE, Ready-to-Use Pre-Mixed Grout data sheet (remove spacers and debris before grouting)
- ARDEX FL Grout installation instructions (no slake time)
Flat tile grouts better. Next Level clips keep edges flush so grout lines come out even, and the reusable wedges go to the next job. The Next Level tile leveling system is sold nationwide by quote. Request a quote for Next Level clips and wedges.