What could be causing cracks to appear in ceramic
floor tiles?
There is always a remote possibility of an individual fractured tile,
usually caused by not being bonded properly and then being impacted by
an object dropping o n it. That type of fracture is repaired by replacing
the damaged tile. A sure rule of thumb to determining the problem: if the
crack goes from one tile to another on a continuous line through the grout
joint, the problem, without any doubt, is in the substrate; usually a crack
in the slab. The damaged tile would have to be removed, a crack
isolation membrane put down and the tile reinstalled; which should solve
the problem.
What is the best way to clean grout?
NEW GROUT: Because cementitious grout is porous, sealing can help to
keep grout joints clean. Allow grout to dry at least 48/hours, then make
sure it is clean before sealing with a sealer recommended for grout.
EXISTING GROUT: A routine for cleaning grout should be established, as
occasionally cleaning with household cleaners containing acid, bleach
or even vinegar will etch the tile and grout in time. There should be two
types of cleaning procedures, regular 'Routine Cleaning' with a
concentrated non-acidic phosphate free cleaner and occasional 'Heavy
Duty Cleaning' when dirty. We recommend for Heavy Duty Cleaning:
Aqua Mix 'Heavy Duty Tile & Grout Cleaner.' NOTE: Epoxy grouts are not
porous and are easier to clean; however, they are more expensive to
purchase and to install.
What is the best way to clean abrasive quarry tile
without leaving mop strings?
First, with any abrasive tile, you cannot use a standard mop as it will be
torn to shreds and leave strings on the floor. A nylon mop will not
normally leave "strings" behind. MOST IMPORTANT: Make sure you
always use clean water. Change as often as necessary. When cleaning
this floor, it must be scrubbed daily (at least) with a brush and, if
available, use a vac system (wet vacuum) to pull up the residue of
water. At least once a week the floor should be cleaned with an electric
floor scrubber. If no vac system is available, surplus water must be
accumulated in one area and gathered up, or some commercial kitchens
have drains for disposal of excess water.
What causes grout cracking?
There are several possible reasons for cracking grout:
1. A flexible substrate (plywood, etc.)
2. Poor installation; tile not bonded, resulting in loose tile.
3. A non-sanded grout was used with the grout joints too wide. When
the grout shrunk, the only possible thing it could do is crack.
4. The grout joint was not completely filled during installation, leaving
voids on the surface.
5. In a large floor installation, where the grout crack is isolated in
specific areas, it is usually caused by the lack of expansion joints.
Can existing dirty grout be re-grouted?
1. To merely apply new grout over existing grout is not the answer
because it will always look like that is what you have tried to do
without success.
2. You can re-grout if you dig out the existing grout and there are
saws specifically designed for this purpose. However, be forewarned
that it is a tedious and exasperating task and it is virtually impossible
to do without damaging some of the tile, which would necessitate
replacement. You would then probably have a problem matching the
color shade of the tile. The saws are actually utilized either with fresh
grout or a smaller area which needs re-grouting; thus they are not
really practical for large areas.
3. The grout can be stained with a grout stain such as 'Grout Colorant'
by Aqua Mix. Available in 22/normal grout colors, plus three vivid
intense colors, Red, Yellow and Blue.
What can be done to eliminate a white film or
powder in grout joints?
The white powdery layer you describe that most often
reforms again after you brush it away is called
efflorescence; which is simply white salt deposits.
These salts remain on the grout joints when the salts in
water solution are wicked to the surface and then the
water evaporates, leaving these salts in powder form. It
seeks out the porous grout joints because water cannot
travel through glazed tile to the surface. Because it is
difficult to say exactly where efflorescence comes from,
it is just as difficult to say when it will stop appearing.
These salts can originate in the grout, the mortar bed,
the concrete slab beneath the mortar bed, or even in the
ground under the slab. They have also been traced to
unwashed sand containing soluble salts, sometimes to
free alkali's in cement, occasionally to chemical
concrete admixtures, and more recently to high alkaline
floor cleaners which absorb into the joints and reappear
as efflorescence. That is the reason they call your
substrate, (ex. slab) "the hidden floor below." It can
even be caused by a failure to install a moisture barrier
between a source of the moisture (the ground) and the
grout joints. Frequently the problem will reduce to a low
level as the underlying moisture evaporates away. The
bottom line, it is excessive moisture (more than normal)
wicking through the porous grout joint.

The first step to eliminate the problem is to let the
installation dry out and the cement cure. During this
process, merely brush off the white powder which will
leave a stain, but do not address the stain until the
wicking (moisture transmission) stops. For the final
cleaning and to remove the stain, agitate the grout joint
with a brush and, if necessary, utilize a neutral cleaner
such as Aqua Mix's 'Tile & Grout Cleaner.' If this fails to
remove all of the residue, it may be necessary to use
sulfuric or phosphoric acid. Sulfuric would be the acid of
preference and three things are mandatory for either
acid:
1. It must be diluted a minimum of 5:1 to 7:1.
2. The surface must be wet prior to administering the
acid.
3. Be sure and wash thoroughly to remove all the
residue of acid.

Allow this to dry and if no more efflorescence appears,
seal the grout joint with a grout sealer. NOTE: If by
circumstance it is a fast track commercial job, the same
process would be followed, except you may not be able
to allow it to dry out as much as possible.  
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CHARLES MCGLAUGHLIN, INC
DBA CERAMIC SOLUTIONS
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