How to grout tile: grouting tips and techniques

To paraphrase Rodney Dangerfield, grout gets no respect. Grout can ruin an otherwise great tile job. And yet how to grout tile and proper grouting technique are often treated as an afterthought, like the final few half-hearted steps of a tired runner stumbling over the finish line. Grout deserves better. Your tile deserves better.

The keys to a professional-quality grout job aren’t secrets shrouded in mystery. On these pages, we’ll show you some tips and techniques on how to grout tile so your job goes more smoothly and give your tile a professional-grade finished look.

Tools Required

Bucket

Caulk gun

Grout float

Margin trowel

Microfibre towel

Putty knife

Shop vacuum

Tiling sponge

Utility knife

Materials Required

Caulk

Grout

Masking tape

Sanded vs unsanded grout

Sanded grout is stronger than unsanded grout and resists shrinkage and cracking better. As a rule of thumb, sanded grout should be used in joints larger than 3mm. Realistically, as long as you can force the grout into the joint, use sanded grout. But on soft stone tiles like polished limestone or marble, use only unsanded grout or you’ll scratch the surface.

Start by vacuuming out all that renovation dust, debris and any chips of dried thin-set from grout joints. If there are high spots where thin-set has oozed out and dried, use a sturdy-edged tool to scrape it out. Don’t scrape too hard or you may chip the tile glazing on your tile project. Then vacuum everything again, including the tile surfaces. The last thing you want is to push all that muck back into the joint as you are floating your grout in.

For easier clean-up, tape off painted walls to protect them from grout. Also tape off trim or inset tiles that feature imprinted patterns with crevices.

Pour some grout out of the bag into a mixing bucket. Pour water in a little at a time and start mixing by hand using a margin trowel. Tip the bucket toward you and roll it in a “cement mixer” style as you mix. Be sure to scrape any dry, unmixed grout from the bottom of the bucket with your margin trowel. Keep mixing until all the powder has been absorbed and it has the consistency of peanut butter. When you’re getting close, dribble in water from a sponge. It only takes a little too much to create soup. And don’t mix grout with a drill and mixing paddle. This method churns the grout and introduces air into the mix. That weakens the cured strength and causes a type of discoloration called “shading.” Besides, we’re trying to mix grout here, not make soufflé.

When your grout has reached peanut butter status, stop! Go and make a sandwich, take out the bins, whatever. Let the grout slake (rest) for about 10 minutes. This allows the chemicals in the grout to work their magic. Skipping this step may result in weaker, crack-prone joints. After slaking, the grout will feel a bit stiffer, but don’t add more water. Remix the grout by hand again to loosen it up.

You’re now ready to grout. Tip the bucket toward you (like you did when mixing) and “drag” some grout with your float up the side of the bucket toward you. This pulls a “working batch” closer to you and makes it easier to scrape up a decent amount of grout onto your float. Push the float tight against the side of the bucket and scrape off a dollop of grout. Any excess that falls off will only fall into the bucket and not off the edge and onto the floor.

Learn more about how to refresh grout.

Smear the grout diagonally across the tile to force it deep into the joints and prevent it from being sucked back out as your float slides along. Use whichever side or corner of the float is necessary to fully compress grout into the entire joint. On vertical surfaces, apply grout upward. That way you won’t drop so much on the floor. Always grout the walls first, and after they’re finished, the floor. That’ll keep you from messing up a finished floor.

After you’ve filled all the joints, make your first “cleanup” passes with the float. Your goal is merely to get as much excess grout as possible off the face of the tile. Hold the float at a sharp angle to the tile and scrape excess grout from the surface by wiping in a serpentine motion. This helps evenly distribute the grout and prevents the grout float edge from digging into grout lines.

Learn how to keep grout tile white.

Once the grout has started to harden (20 to 30 minutes), begin sponging. Don’t use just any sponge, especially one from the kitchen; choose a “hydrophilic” (water-loving) sponge. They’re sold near the tile supplies. Make sure it’s damp, not wet, and sweep diagonally across the face of the tile and wipe the grout off the tile surface. On your first few passes, the grout will smear all over the tile and look like a mess — that’s OK. Just rinse out your sponge often in a bucket of clean water (never in the sink) and keep wiping until most of the smeared-on grout is gone.

When the surface has been cleaned, begin ‘tooling’ (smoothing and levelling) the grout lines with the sponge. Hold the sponge in your palm and, gently pressing down with your index finger, run the sponge over any grout joints that look too high or uneven. The goal of this how to grout tile project is consistent, even-depth grout joints. Don’t push too hard; let the sponge do the work.

After all the joints have been dressed, step away for about a half hour to let the surface dry and form a haze. Then wipe away the haze with a towel. Regular towels work, but microfibre towels are the hot ticket for this job. With more fibres, they remove grout haze much quicker and cleaner than a regular cotton towel.