Step 1: Plan the project and assemble tools and materials
By itself, the tile in a shower enclosure is almost maintenance
free. With an occasional wipe-down, it can
look good for years. Grout, however, is a different
story—eventually it's going to break down. Large cracks and
crumbly chunks are alarming, but smaller fractures can be
trouble too. Fractures, and stains that won't wash out, may
indicate spots where water is wicking in and working its way
behind the tiles. Sooner or later, that water will weaken the
adhesive that's holding the tile or cause rot in the walls. When
that happens, the only solution is to tear out the tile and start
The good news is that if you catch it in time, you can quickly
and easily give tiled surfaces a new lease on life—and a fresh
look—by applying a new layer of grout. In this article, we'll walk
you through the regrouting process from start to finish, and
offer some tools and tips to prevent mid-job mishaps. You don't
need previous tile experience; regrouting is mostly grunt work.
The materials needed for an average-size shower are inexpensive. In some cases, you can finish the job in a few hours, but to
be safe, give yourself a weekend. If you start on Saturday morning,
you should be able to take a shower on Monday.
Choosing the right tools and grout
Before you begin digging into that old grout, make sure you
have all the tools and materials you'll need to finish the job. To
help make sense of what you'll need, think of this project in
three parts: scraping and cleaning, regrouting and cleanup.
When you're choosing grout-removal tools, stick with steel to
be safe. Many special grout scrapers equipped with carbide tips
work well and stay sharp for a long time, but if you slip, the carbide
can damage your tile or tub. Steel utility knife blades, on
the other hand, may dull quickly, but they're less likely to
scratch the tile. Buy a knife with easy-to-change blades, and also
buy plenty of spare blades (buy a
100-blade pack). They're ideal for
cleaning out narrow joints. A
grout saw (Photo 2) with a
notched steel blade is also
handy for snagging chunks of
As for grout, buy a 10-lb.
Bag—you may have some left
over, but that's better than running
out. Grout comes in two
forms: unsanded and sanded. Your choice depends on the width
of the gaps between the tiles. For joints up to 1/8 in., choose the
unsanded variety. For wider joints, choose sanded to avoid
cracking. Whatever type you need, look for a “polymer-modified”
mix. The extra ingredients help prevent future cracking
and staining. It's almost impossible to match new grout to old,
but don't worry. By scratching out the topmost layer from all
the grout lines and adding new, you'll get a fresh, consistent
Tip: When you're shopping
for grout, stick with
brands that offer color-matching
blend almost perfectly.
To apply the grout, buy a rubber-soled grout float and a
grout sponge (both from home centers). In case the grout starts hardening too quickly,
you'll also want to buy a plastic scouring pad (see Editor's
Note, below). Last, buy a tube of tub-and-tile caulk
that matches the grout color.
A special scraper and grout remover
When the Going Gets Tough
The basic arsenal of simple scratch-out tools works for
most projects, but there are times when you might
need a little extra help. This pair of not-so-secret
weapons can make short work of super-stubborn
grout and caulk.
The first is a Grout Grabber. Attached to your
reciprocating saw, this carbide-tipped clean-out tool
works like a steroid-fueled electric toothbrush.
Controlling the blade so it doesn't scratch the tile takes
some getting used to, so start with light pressure.
Once the blade digs in, it's not too difficult to keep it
on the path.
The second weapon is 3M's Caulk Remover.
You'll find it indispensable if the previous installers used
silicone caulk to seal cracks around tubs and showers.
Silicone's stickiness can
make removing it a real
headache. The chemical
requires a few hours to
soften stubborn caulk, but
waiting is better than the
tedious chore of scratching
off the silicone remnants
with your knife and possibly
damaging your tile or tub.
Step 2: Slice out caulk and scratch out grout
Before you begin your attack, take a minute to protect your tub
against scratches and debris that can clog your drain (Photo 1).
Tape a layer of plastic sheeting to your tub's top edge. Next, lay
a drop cloth on top of the plastic to protect the tub and cushion
your knees. Then remove the faucet hardware or protect it with
Getting rid of the old caulk and grout requires plenty of
elbow grease, but it's not difficult work, especially if you take
your time. Begin by cutting out the old caulk (Photo 1) and
then move on to the grout (Photo 2).When you're using a utility
knife, switch blades as soon as the edge stops digging and
starts skating on the grout (Photo 2). At times, you may have
more success with the grout saw. Whatever tool you choose, the
goal remains the same: to remove about 1/8 in. from the top (or
more, if the grout comes out easily).
When you're done, remove dust and debris, which can weaken
the bond between the tile and the new grout (Photo 3).
Step 3: Mix the grout and pack the joints
Once the grout is mixed, the clock starts ticking toward the
moment when it will harden on the wall…or in the bucket. Pro
tilers can mix and use a 10-lb. bag of grout before it hardens, but
to play it safe, mix up a few cups at a time and work in sections.
A smaller batch will allow you plenty of time to apply it and
clean the excess from one wall at a time. When you run out,
rinse the container before mixing a new batch.
Before you make a batch from a bag, shake the bag to redistribute
any pigment and Portland cement that might have settled
out in shipment. After it's been dry mixed, scoop out a few
cups (one cup equals about a half pound) into a bucket. The
instructions on the bag indicate how much water to add per
pound of mix. To ensure a strong mix, start with about three quarters
of the specified amount of water and gradually pour in
just enough to make the grout spreadable. Aim for a fairly stiff
consistency, somewhere between cake icing and peanut butter
(Photo 4, inset). Don't worry if the grout looks a little lumpy.
After it's mixed, allow it to sit, or slake, for 10 minutes. During
this time, the remaining dry specks will absorb moisture. Give
the grout one last stir (restirring also keeps the mix from hardening
in your bucket) and it's ready for application.
Focus on one wall at a time. Scoop out a dollop and press it
out across the tiles at a 45-degree angle (Photo 5). It's OK to be
messy. The goal is to pack as much grout into the joints as you
can. Press hard and work the float in several directions.
Step 4: Scrape off grout and sponge clean the surface
Immediately after you fill the joints, rake off the excess grout.
Hold the float on edge, like a snowplow, and cut off most of the
excess (Photo 6). Move the float across the joints diagonally to
prevent the edge from dipping into the joints and pulling out
too much grout. Work quickly before the grout starts to harden.
The time between scraping and sponging varies from job to
job. Depending on your mix, the humidity or the temperature,
the grout may take anywhere from five to 20 minutes to firm up.
Begin sponging as soon as the grout feels firm and no longer
sticks to your finger.
Using a well-wrung tile sponge, wipe away the bulk of the
unwanted grout with short, gentle, circular strokes (Photo 7).
Turn the sponge so that you're using a clean edge with each pass.
Rinse and wring it out in the “dirty” bucket, then dip the sponge
in a “clean” bucket, and finally wring it out again in the “dirty”
bucket. This two-bucket technique helps keep your sponge and
rinse water clean so that you can remove grout more effectively.
Wring out as much water as possible. Too much water can pull
cement and pigment from your fresh grout lines.
In addition to wiping away the excess, the sponge works for
fine-tuning the shape of your grout lines. To shave down any
high spots and make the lines slightly convex, run the sponge
across the joint until the grout lines appear uniform. (If you
find a low spot, use your finger to rub in a little extra grout.)
Editor's Note: Scrub Pad Insurance
The biggest mistake you're likely to make is waiting
too long before sponging the excess grout off the tile.
I've discovered that it only takes a few minutes before
a shower stall can start looking like a sidewalk.
A plastic scrub pad is a cheap insurance policy.
The coarse pad quickly and easily scours off hardened
grout that would shrug off a sponge, but it won't
scratch the tile. (In addition to emergencies,
I like using it to tweak the shape
of my grout lines.)
Of course, buying one may guarantee
that you won't need it. On
the other hand, should you need
one, you won't be able to drive
to the hardware store fast enough.
Step 5: Scrape and buff
Scrape out any globs of grout that may have gotten
into the joints you intend to caulk (Photo 8). This includes all
corners and the tub/tile joint. You could do this chore later, but
it's a lot easier now, before the grout is rock hard.
The sponge-wiped walls may look clean at first, but as the
surface moisture evaporates, the remaining grout particles will
create a light haze. Give the grout an hour or two to dry, then
buff off any residual haze with a soft towel (Photo 9).
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Step 6: Finish up with neat caulk joints
Let the grout dry overnight before applying the caulk along the
tub/tile joint and inside corners. For clean, precise caulk lines,
run painter's tape along the inside corner and at the tub/tile
joint (Photo 10). Just remember to remove the tape as soon as
you finish smoothing. If you wait too long, the caulk will skin
over or stick to the tape and you'll pull out the caulk when you
try to remove the tape. Depending on the caulk, your bath
should be ready for an inaugural shower in 24 hours.
To reduce mold growth, seal grout lines for extra stain and
water resistance. Give the grout a week or two to cure completely
before sealing. Remember that sealers wear off in time, so
you'll need to reapply it every year or so. If you don't want to
apply a sealer, wiping your walls down with a squeegee after
each use works almost as well.