View wishlist
Leave feedback
Find a tiler
  • My wishlist (0)
  • Trade portal
  • Login / Register
  • 0
    • Shopping Cart Empty
    Subtotal $0.00

Ask Luigi

My tiles have just been laid but they look all dirty and patchy.

Some tiles in my order are not square

Some of the tiles in my bathroom have gone a darker colour

Why do my polished tiles look patchy and hazey?

My tiles are different to the sample I selected from.

My dark grout is turning white and patchy.

My tiles are not perfectly flat.

I have a crack or cracks in my tiles.

My White tiles have black grout stain.



Question: My tiles have just been laid but they look all dirty and patchy.

Luigi’s Answer:
Your tiles will be coated in a thin layer of grout, commonly called grout haze. Sometimes this is hard to see but usually it shows as a greyish haze.

What causes the problem?
When the tiler is grouting your tiles, the grout gets spread across the tile surface as he works it firmly into the joints. As the grout dries he will wash off the excess grout, but there may still be a fine layer behind which the tiler should buff off.

Luigi Suggests:
The haze needs to be removed as it is a wonderful dirt trap that will only make your tiles look worse over time.
If tackled within 2 or 3 hours of laying the haze will probably come off by buffing with a towel. The longer its left the harder it sets.
Like all cleaning, its best to start with the least aggressive approach

First try washing with hot water. Scrub with a stiff brush or Jiffy pad. Rinse off with clean water, changing the water regularly.
Then if that doesn’t work try scrubbing with Aqua Mix Nano Scrub - read the label, follow the instructions and always do a test area first.
Finally for extra stubborn problems use Aqua Mix Phosphoric Acid Substitute. This is an acidic based product so use with care. Read the label, follow the instructions and always do a test area first. Even better get hold of your tiler to finish his job properly!!

Once your tiles have been cleaned, seal the grout with Aqua Mix Grout Sealer or similar.







Question: Luigi, I have some tiles in my order that are not square. Is this normal?

Luigi’s Answer:
Yes! Although it is uncommon for modern ceramic and porcelain tiles to be out of square, the International grading standard for pressed tiles allows up to 0.6% deviation from rectangularity. If you believe that your order does not meet these criteria, please speak to your local Tile Depot branch before you commence installation.

Ceramic tiles are manufactured by  ring raw materials such as clay at high temperature in a kiln. The process is very similar to baking cupcakes; once the cakes are cooled, they may vary in size and shape even though the same recipe was used to bake them.
The same process is followed for tiles, just on a much larger scale. The exact size of each tile can only be determined once the tiles are out of the kiln and have cooled down. At this point the tiles are sorted to remove defective pieces and to arrange the tiles into batches of similar size. This sorting is done to a number of different criteria with individual tolerances. 0.6% is the tolerance for squareness.

Luigi Suggests:
• Once you have received your tiles, they need to be checked for defects. Any tiles that have slight problems should be put aside to be used for cuts.
• Setting the tiles with a wider grout space will make any variations in sizing less obvious to the eye.
• When you purchase your tiles, make sure that you have estimated enough tiles to cover the
intended area. You also need to allow for wastage in your calculations; for tiles up to 450mm an additional 10% is generally adequate whereas you may need up to 20% extra for larger format tiles. If you are unsure please ask the friendly staff at your local Tile Depot.

What to do if :
• You have more defective tiles than the 5% allowed by International standards?
If you believe that your order breaches the International standards, please contact your local Tile Depot branch as soon as possible before your tiles are installed.
• You are in the above situation, but your tiles are already installed?
Unfortunately we cannot accept claims for defective tiles once the tiles are installed. Tiles should be checked by the installer before the tiles installed to avoid defective tiles being laid.







Question: Why have some of the tiles in my bathroom gone a darker colour?

Luigi’s Answer:
All tiles absorb water to some degree, even low porosity porcelain tiles. The problem here is that the biscuit or body of the tiles have become saturated with water.
As the biscuit soaks up water it becomes darker and if the glaze on the tile is white or a very light in colour it tends to be translucent or see through. The wet tiles then appear darker than the ones that have remained dry.

What causes the problem ?
Most tiles are not intended to be continuously emmersed or exposed to moisture. Somehow water has got behind or under the tiles in sufficient quantity to soak into the biscuit. The glazed surface of a tile is impervious but there are a number of ways water can get behind the tiles or be allowed to accumulate:
- Grout penetration; most grouts are not impervious and it only takes a pinhole for water to find its way. - Poorly grouted tiles eg joints not fully compacted, edges of tiles left exposed.
- Cracked or damaged grout
- Internal corners and bottom row of tiles not siliconed properly or at all.
- Tiles wernt bedded into the adhesive fully. Wet areas require 100% adhesive coverage.No voids please.
- Poorly formed shower base , inadequate or partially blocked fall causing ponding on top of or under the tiles. - Puddle flange not or incorrectly fitted around waste.
- Taps not sealed and waterproofed where they meet the tiles.
- Shower recess was never waterproofed or waterproofing has failed.
- Leaky waterpipe behind the wall.

What can I do?
The tile discolouration could be the sympton of a serious problem so needs to be attended to promptly.
It is not a problem with the tile, but the installation or perhaps a serious water leak.
If your shower is covered by warranty call your Builder or waterproofer,

If not:
1. get a plumber to test for leaks in the pipewater or water service.
2. If the watermarkng is not very bad, and the grout and silicone look to be in good order you might be able to dry the tiles out without removing the grout and silicon sealer and hopefully solve the problem by applying a penetrating sealer to the grout.

However drying the tiles until they revert back to normal colour may not be possible without removing the grout as even then it will take some time as the moisture can only escape from the edges of the tiles. If the grout & silicone is removed, take care not to damage the waterproof membrane. Drying can be sped up by the use of a fan heater. Then regrout the tiles with grout mixed with an additive instead of water taking care to fully pack the joints and leaving no edges exposed.
Once the grout is dry apply a penetrating sealer to further reduce the grouts porosity.

Unfortunatly if this does not solve the problem there is no option but to retile the whole shower enclosure, making sure the correct installation procedures are followed.








 Question: Why do my polished tiles look patchy and hazey?

Luigi's answer: This is most likely a common case of optical hazing on Polished Porcelain

Over the years we have had a number of customers asking the same question. It is possible the tiles are just greasy or dirty or over sealed or have grout haze left on them and just need a good clean… or ... it could be due to optical hazing.


Optical hazing on polished porcelain tiles is not a new phenomenon; it has occurred in natural stone and the painting industry for hundreds of years. Many consumers have expectations that their polished porcelain floor is going to have a mirror like finish. A polished porcelain tile is not a mirror. When the surface of a polished porcelain tile is examined under significant magnification, small micro facets are always found. Light that strikes such micro facets reflects in a diffused manner giving a “Halo” or “Haze” effect. 

If a ray of light could be observed approaching and then reflecting off a mirror, the behaviour of that light as it reflects would follow a predictable law known as the law of reflection.  The ray of light approaching a mirror is known as the incidence ray (R)  The law of reflections states, “that the angle of the light rays striking a surface is equal to the angle of the reflected light” (see figure 1)

Figure 1


If reflected light is so predictable, then why does it reflect differently off different types of surfaces? Reflection off a smooth surface such as mirror or calm body of water known as specular reflection (see figure 2)

Figure 2 


Reflections off a rough surface such as honed or tumbled stone such as granite, limestone, marble, slate, sandstone and other types of stone is known as diffuse reflection (see figure 3)

Figure 3


Whether the surface is microscopically rough or smooth has a tremendous impact upon the subsequent reflection of a beam of light. A beam can be thought of as a bundle of individual light rays which are travelling parallel to each other. Each individual light ray of the bundle follows the law of reflection. When the bundle of light rays strikes a smooth surface then the light rays reflect and remain concentrated in a bundle upon leaving the surface (Fig 2). On the other hand, if the surface is microscopically rough, the light rays will reflect and diffuse in many different directions (Fig 3). 


  • The number of light sources and their positions i.e. a single source of light would mean there would be a limited number of positions available to observe any haze. The same surface when lit by a number of light sources will increase the amount of haze visible because there are more opportunities to see the reflected light. Another example is bulk sunlight shining through large windows and doors early in the morning; the large volume of sunlight will increase the amount of “Haze” visible.
  • The size of the clay particles and other ingredients of the tiles can also have an effect on the amount of haze visible.


Optical hazing is not a defect, it is an inherent characteristic of the tiles stemming mainly from the mineral content and their manufacture. It has no effect on the technical performance of the tiles. No amount of cleaning, sealing or polishing will make a definitive difference to the appearance of the tiles as it is something that occurs during their manufacture and not caused by any subsequent cleaning or treatment of the tiles surface. Using a light coat of a penetrating sealer may help to deepen the colour and fill some of the open micro – facets, which are contributing to the refraction of light effect and therefore disguise the effect. Apply a light coat of sealer to the surface of the tiles and leave for 5 – 10 minutes. Buff using an absorbent cloth while the solution is still wet on the surface to work the solution in and remove excess from the polished surface. For maintenance avoid strong detergents, use a mild ph detergent such as Aquakleen Floor Tile Cleaner. Always buff polished surfaces with a dry towel after cleaning.

Please note that this information is offered as general guidance only and without guarantee. Your specific circumstances may need an alternative approach. In case of doubt, any process should be tried out in an inconspicuous area before general application.

Important to note: as per BRANZ guidelines, inspection of work should be taken from a 'normal' position.

  • Standing at a distance of 2m or more from surfaces
  • an ubostructed viewing angle no less than 45 degrees
  • under uniform non-critical lighting of 500 lux - a typical indoor light level








Question: My tiles are different to the sample I selected from.


What causes this problem?

Ceramic tiles are produced from natural raw materials. Each batch of tiles that are produced tend to be a different shade or size to the ones that were last made. The final kiln temperature, slight changes in glaze mix, and many other variables can affect the final appearance and size.


Luigi Suggests

Whilst we update our in store samples as often as we can, it is highly unlikely that the sample you view in store will be from the same batch as the stock that your order is picked from. This is the main reason we encourage all customers to dry lay 3-4m2 of tiles on site once they are delivered, to ensure they are happy with the shade and variation BEFORE installation.

If the shade that is delivered to site is different from the original selection, and you are not happy with the current batch, contact the Tile Depot outlet with which you have been dealing. The first thing we can do is try to find some stock that is closer to the selected shade. If we can't find a suitable shade, the only option left is to select another tile.

Finally, if we have nothing suitable, we would need to arrange a credit for the tiles. Naturally, once the tiles have been installed, we cannot be responsible for any variation in shade to the original selection.










Question: My dark grout is turning white and patchy.


Luigi’s Answer: Under certain circumstances, a white powder can form on grout, especially on floor tiles. This is a natural phenomenon known as efflorescence. It is due to soluble salts rising to the surface of a cement based product. When they dry out on the surface, the remaining salts appear white and powdery.

What causes the problem?

There are many examples where Effloresence appears in some situations but does not appear in others, under the exact same circumstance. It is quite a mystery in the tiling and brick-work world.  We do know that it is a reaction when Portland cement is present, and that there is no real solution for it. Efflorescence does clear up over time unless there is an ongoing issue with rising damp from the substrate. It is simply showing the effects of the soluble salts coming from beneath the tiles. It is not due to substandard tiles, adhesives, or grout; and generally, (other than aesthetics) there is nothing to worry about.            

Luigi Suggests:

The only real solution is to brush the grout with a stiff bristled brush and vacuum away. Repeat this from time to time, and eventually, it will generally stop recurring. You can use specialist products such as Aquamix Eff- Ex. 




Question: my tiles are not perfectly flat.

Luigi’s Answer: Curvature occurs in almost all tiles due to the firing process with which they are made.

Discussion: The centre of the tile is the highest point with the ends being the lowest. Curvature generally becomes noticeable when tilers attempt to brick lay tiles at 50% overlay. The global manufacturing recommendation is to not overlap any large size tiles more than 33%. Curvature is normally not an issue when the tiles are laid block stacked as the low points (ends) and high points (middle) align tile to tile. 50% overlap will mean the lowest point is aligned against the highest point of the next tile, leaving a lip or ridge between the two.

What to do if: The safest way to avoid this issue is to ensure your tiler does not overlap more than 33%. Dry lay a few tiles to ensure there is no problem before instalation. Prevention is better than cure.

 The use of tile levelling systems will help minimise height differences but these won’t work if there is insufficient adhesive behind the tile…. make sure your tiler is not blob gluing!






I have a crack or cracks in my tiles.

Luigis Answer: More often than not the problem is not with the tile itself but with the material below the tile and because the real cause is hidden below tile, it's difficult to investigate. The tile is likely to be showing the stresses beneath it or the result of a poor installation job.

What causes this problem?

There are seven likely causes:

Cause 1: The concrete substrate didn't cure for long enough.

Newly poured concrete is full of water.  As the concrete cures, the water evaporates and the concrete shrinks. New concrete should cure for as long as possible or at least for 28 days. If your customer has a new home and the tile has cracked, it is a distinct possibility that the concrete did not cure long enough. A moisture test will clarify the issue.

Cause 2: The concrete substrate is cracked.

Almost all plain concrete basement floors, driveways and patios have a few long cracks running through them especially if it the concrete is a few years old, Even though concrete seems like the perfect substrate for tile, it too has its own problems.  When concrete substrate cracks, this is transmitted to the tile above in the form of a reflective crack.  If the tile cracks are long, continuous, and extending across multiple tiles, likelihood is high that the concrete below has cracked. The way to eliminate this happening is to install a crack isolation membrane during installation.

Cause 3: A hard, sharp knock.

If the crack is located in one area, extending across only a single tile, this is probably the case.  Especially in kitchens, where heavy objects such as cans, pots, and pans get dropped, ceramic tiles frequently break.  Standards do not regulate sharp blows to tile. Sometimes, you will also see a chip taken out of the tile where the object hit. This counts as normal wear and tear. We encourage all customers to keep spare replacement tiles at the completion of their project. It is very unlikely you will find more stock of the same batch of tile you originally received.

Cause 4: A very heavy load.

Tiles are required to be in compliance with breaking strength standards.  Most tiles meet and exceed these standards.  Even commercial kitchen equipment like refrigerators don't exert enough ground pressure to exceed the breaking strength of tiles. Unless there is something really heavy on site this is probably the most unlikely cause. One thing which might do it is industrial machinery or commercial sliding security filing racks. Paper gets very heavy! Tiles are simply not the right flooring to use under heavy industrial equipment.

Cause 5: Tiles installed over a concrete control joint

Control joints are expansion gaps to allow for heat expansion of concrete slabs. Since it is almost certain that concrete will crack, expansion gaps are effectively pre-planned cracks. They are intended to create a weakened area in the concrete and regulate where cracks will occur, normally in a straight line. It is not sensible or good practice to use tile to bridge a line that you know in advance will expand.

Cause 6: Tiles have lifted and cracked

This is quite common. Lifting (called tenting) will lead to cracking. Tenting is primarily caused by poor installation or inadequate grouting and expansion joints at the edges of the room and at room entrances or along very large or long rooms like passages. Of course if tiles lift they are no longer firmly based and bonded to the substrate so hollow sounding spaces start appearing underneath. This in turn means that if weight is placed on the tile it is prone to crack. The forces created by tiles expanding against each other may in themselves be enough to crack tiles. Improper use of adhesives can also be the cause e.g. Using the spot method where only five spots of adhesive are used instead of firmly bedding the entire tile.

Cause 7: Sub-standard tiles

This is unlikely but it is what many customers initially believe to be cause. Because the tile is cracked, and the tile is the only visible portion of the installation layers from substrate to tile, most homeowners assume that the tile is at fault. Nonetheless double check that the tiles you supplied are in compliance with ISO, ANSI or ASTM testing standards. It is possible that transit damaged can cause small hair line cracks in a tile that if the tiler doesnt identify can be installed.  This is not considered a tile fault and a simple replacement is necessary. What is unfortunately quite common is an absorbent wall tile may have been foolishly installed as floor tiles!





Question: Black grout has stained my white tiles?

Luigi’s Answer:

Cementitious black grout is very difficult to clean up because it is so heavily pigmented.  It can stain porous tiles or even glazed ceramic tiles by sitting in the microscopic pores.

Despite disclaimers, tilers will often proceed using dark grout on white wall tiles and providing they are extra vigilant and carefully clean as they go, can have a problem free instalation. Every brand of grout and batch of tiles will react differently so always test prior to installation. 

The safest solution and the recomendation of The Tile Depot is the use of Aquamix Grout Release prior to grouting.

For problem shooting, a poultice may be able to draw out the pigment or the use of diluted vinegar has been proven to work on occasion. We suggest Aquamix Poultice Stain Remover.

Find a store near you

No query specified.