Understanding Tile Tenting Complaints

Tenting and delamination are the terms used to describe what happens when an area of tiled floor lifts centimetres off the substrate beneath. In the tile business the phenomenon is called tenting when the tiles lift, because the lifted tiles look like rows of peaked camping tents. The forces involved can be extremely powerful. In the photo above you can see the tented tiles lifted up an entire store gondola! When the tiles simply come free from the substrate without tenting it is called delamination. Close inspection often shows that more than one area of the floor has delaminated. Several sections might have lifted, not necessarily simultaneously but very close to it. And then, at times the delamination is only apparent when the floor is tapped upon or when someone walks across it wearing hard shoes and the floor doesn’t sound solid but rather hollow instead. As with most complaints tenting is generally caused by poor installation technique.

There are several reasons why a tile floor might delaminate:

• the floor might not have been cleaned prior to tile installation;
• the setting mortar might have partially dried before the tiles were placed in it;
• the tiles themselves might have had dust or other contaminants on their backs.

The main reason, however, that tiled floors delaminate and tent is because of a lack of movement accommodation. Tiles have a different rate of expansion and contraction (the coefficient of expansion) than concrete for example, the material that ceramic tiles are often installed directly upon. Other common tiling substrates will also expand and contract differently than ceramic and stone tiles.

Concrete expands and contracts more than many other tiling bases. The difference between concrete’s rate of expansion (and contraction) and that of ceramic tile is about 10 to 1. A concrete slab one hundred feet across can grow and contract over half an inch. It only takes a fraction of that movement to cause a tile floor to delaminate. Knowing this, tile setters employ breaks in tiled floors to accommodate that movement. These are called movement joints and are placed at specified intervals to divide large tiled surfaces into smaller expanses and thus lessen the effect of substrate movement. The joints are then filled with flexible material instead of tile grout.

In addition to movement joints in the tiled field, perimeter movement joints are used where tile floors abut impediments to movement, i.e., walls, cabinets and the like. Whereas smaller tiled floors may not need movement joints in the field of tile, all tile floors need perimeter movement joints and it is the lack of perimeter joints that most often contributes the greatest causal force to a tented floor, even though other factors; contaminants, skinned over setting mortar and other installer errors, may come into play also. The fact that I used concrete floors as my example doesn’t eliminate other tile substrates from the need for movement joints.  All substrates move, albeit some less than others. Cement backer board, for example, is an excellent base for ceramic tile when the board is properly installed, but movement joints must still be provided. Various tiling membranes, both sheet and semi-liquid, can further improve longevity of tiled floors over any substrate, but every manufacturer of such membranes will specify that movement joints be employed.

The clause in our disclaimer pertinent to this issue reads as follows:
"When tiling large areas allow for expansion joints, generally every 5x5m area. Ensure that perimeter joints are in place and free from any adhesive and or grout."

Even in tough environments, properly installed tile floors with movement/expansion joints will last virtually forever.

How can tiles wear out?

The problem of wearing.

Tiles are well known for their durability and wear resistance, but they are not indestructible. If mistreated, or subjected to harsh conditions, or incorrectly selected for purpose, the glaze on a ceramic tile will scratch or wear away. There is a difference between wearing and scratching. Wearing is where the glazed surface is thinning and eventually actually worn through. Scratching is damage to the surface from a harder substance that scratches the glaze. Heavy scratching can give the effect of making the surface of a glazed tile look dull. This is damage to the surface, but not actually wearing through. Even solid granite slabs in a heavy traffic area will dull from scratching. If you have ever been in an old castle you will have noticed that over the centuries solid stone stairs wear away until the are distinctly hollowed. The best way to avoid tiles becoming worn is to select tiles appropriate to the traffic; proper porcelain for high-traffic and commercial spaces. The other way is to keep the floor clean and free from sand and abrasive dirt. This is especially important at doorways and entrances.

What can cause the problem?

Abrasive grit is brought in under shoes. Gravel can be very hard and if it is trapped under a shoe and then trodden onto the tiled surface it will cause scratches and wearing. Not having doormats at entrances to remove grit and sand from shoes is a major factor. The effect of grit underfoot is like sandpaper. Your professional advice to customers is crucial. When advising a customer make sure you determine where the tiles are to be laid and how much traffic the area will receive. Recommend a suitable tile with the right wear resistance. Porcelain full body tiles rather than glazed are the best for high traffic areas as even with massive wearing the colour will not appear to fade.

In the worst case, soft glazed wall tiles, laid on a front porch or other heavy traffic area will wear through very quickly. Advise the customer to keep tiles clean. A clean tile won't have a film of accumulated grinding dirt on the surface. Advise against using unnecessary chemicals, especially acid based ones or using hard cleaning implements such as steel wool. These will deteriorate the surface of a tile.

Once the glaze on tiles has worn, it can't be rejuvenated. Likewise, damage by harsh scratching can not be reversed. Scratched tiles will continue to perform as a tile should. But, once a tile surface has worn through, and the protective glazed surface is gone, the tiles will have to be replaced.

What are the hardest wearing tiles?

Our Titan full bodied porcelain tiles are amongst the hardest wearing tiles in our collection.
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3 Water-Saving Products for Real Water Saving

Showerheads, handshowers and bathscreens: By retrofitting a bath with a bathscreen and a hand shower and having a shower rather than a bath is a massive saving on water every day! Water-saving shower heads are designed the same way as the taps we mentioned but also have settings so the optimum spray can be used. Now everyone in the home can have the shower they like best but overall it will save water.

View our shower collection

Aerator taps: Taps that are fitted with aerators increase the apparent pressure while actually reducing the flow. This makes rinsing dishes or hands more effective with less water! Because the hydraulic action of the jet combined with air is more effective than water alone. Without an aerator, water usually flows out of a faucet as one big stream. An aerator spreads this stream into many little droplets. This helps save water and reduce splashing.

View our tap faucet collection

 
Dual flush toilets: Quite simply only use the amount of water you need for the purpose.

View our sanitaryware and toilet collection

How to Deal with Customer Complaints of Shade Variations in Tiles

The variation of color, texture, and tone between individual ceramic tiles is properly called ‘color shade variation’ . Variation in color and shade is an inherent characteristic of any fired tile and rather than being a problem can actually enhance the character and beauty of the finished project, however many customers want absolute consistency and this leads to complaints.
 
The key point is that shade variation should be noticed before tiles are laid. Let me tell you a story that happened in our company.
 
We went to visit a client on site following a complaint. The client showed us the laid tiles and asked
   “Can you see it? There’s variations in shade all over!”
 
Mike agreed;
   “Yes I can see it clearly. Can you see it too?” He asked, turning to me.
   “Oh yes I can see it.” I replied
 
He then turned back to the client;
   “So if we all agree that we can see it, why couldn’t your tiler see it?”
 
This comment put the conversation back on an even footing. Even if there were excessive variations in the batch it is the tiller's responsibility to check for variations before fixing the tiles

All tile disclaimers contain the warning that prior to any installation, the tiles should be approved by the customer. No claims for shade or texture variation will be honored after installation. The shade number is marked on the boxes. National standards and codes of practice all insist that boxes be mixed and tiles be dry-laid under good lighting conditions to ensure tonality is mixed. Variations are classed as follows:
 

• V1 UNIFORM APPEARANCE - Minimal to no difference among pieces from the same production run because each ceramic tile is manufactured using the same glaze applications and body texture. 
• V2 SLIGHT VARIATION - Distinguishable differences in texture and/or pattern within similar colors.
• V3 MODERATE VARIATION -Though the colors present in a single piece of ceramic tile may indicate the colors to be expected on other tiles, the amount of colors on each piece might vary significantly.
• V4 RANDOM / DRAMATIC VARIATION - Random color variation from tile to tile, so that one ceramic tile may have a totally different color from that on other tiles. Thus, the final installation will be unique which may well be the effect the customer is aiming for.

Shade variation is inherent in all tile products, including porcelain, glass & ceramic simply as a result of the manufacturing process such as miniscule changes in temperature or fractional differences in glaze composition.

The color shade varies to some degrees in pieces of ceramic tile, in every style and from each production run. You should review several pieces of the same style of ceramic tile from the same production to decide for acceptable color shade variations. A final point, remember that shades of color are seen differently on computer monitors and therefore customers should request a sample before making a final selection or purchase.

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How to Measure Tile Hardness

Tile hardness is a key issue in determining whether a tile is suited to a particular application. High traffic areas require a harder, more resistant surface.

Hardness is measured using the Mohs scale of mineral hardness, generally called the Mohs hardness scale, is used by geologists all over the world as an identifying tool for minerals. Quite naturally it has also been adopted by the tile industry as a scale to measure the hardness of tiles. Tiles after all, are really just artificial stone. The pressing and firing simulate the process by which metamorphic rocks are formed deep in the earth.

The basic principle of the Mohs scale (no apostrophe) is the scratch resistance of a softer mineral being scratched a harder mineral.

Developed in 1822 by Friedrich Mohs a German Geologist and mineralogist, it is one of several methods used to describe the hardness of minerals and materials in science, however it is the one most commonly used. Although it has been 200 years since the first implementation of the Mohs hardness scale, the method of comparing one mineral to another to ascertain its hardness is much older. The technique was mentioned in 300BCE by Theophrastus in his treatise On Stones.

The Mohs scale is strictly a relative scale, but that's all that anyone needs. In terms of absolute hardness, diamond (hardness 10) actually is 4 times harder than corundum (hardness 9) and 6 times harder than topaz (hardness 8). Because it isn't made for that kind of precision, the Mohs scale uses half-numbers for in-between hardnesses. For instance, dolomite, which scratches calcite but not fluorite, has a Mohs hardness of 3½ or 3.5.

The hardest known substance to man at the time of the scales creation was diamond which is at the top of the scale*.

The Mohs Scale.

TALC- Mohs hardness 1- Absolute hardness 1

GYPSUM- Mohs hardness 2- Absolute hardness 3

CALCITE- Mohs hardness 3- Absolute hardness 9

FLOURITE- Mohs hardness 4- Absolute hardness 21

APATITE- Mohs hardness 5- Absolute hardness 48 (B2b CERAMIC >5)

ORTHOCLASE FELDSPAR- Mohs hardness 6- Absolute hardness 72 (B1a PORCELAIN >6)

QUARTZ- Mohs hardness 7- Absolute hardness 100

TOPAZ- Mohs hardness 8- Absolute hardness 200

CORUNDUM- Mohs hardness 9- Absolute hardness 400

DIAMOND- Mohs hardness 10- Absolute hardness 1600

 

You can buy a set of “Mohs mineral pencils” a set of pencils each mounted on the tip with a small piece of each of the minerals above, these for geologists are often more show pieces, and in the field it is important to know the hardness of ordinary materials to make mineral identification easier. A steel knife (very good for many applications in the field) has a hardness of about 6-6.5 whist a fingernail has a hardness of between 2 and 2.5. Just these two tools can make mineral identification so much easier!

Hardness of some other items.

• 2.5 Fingernail
• 2.5–3 Gold, Silver
• 3 Copper coin
• 4-4.5 Platinum
• 4-5 Iron
• 5.5 Steel knife blade
• 6-7 Glass
• 6.5 Iron pyrite
• 7+ Hardened steel file

In recent years man-made nanomaterials have been produced that are harder than diamond. Currently two rarely occurring natural minerals have topped the scale. Only small amounts of wurtzite boron nitride and lonsdaleite exist naturally or have been made in the lab so it has been difficult to test them accurately however they are calculated to measure 18% and 58% stronger than diamond respectively.

How to perform a Mohs test yourself.
Difficulty: Easy
Time Required: Seconds

1. Find a clean surface on the specimen to be tested. 
2. Try to scratch this surface with the point of an object of known hardness, by pressing it firmly into and across your test specimen. For example, you could try to scratch the surface with the point on a crystal of quartz (hardness of 9), the tip of a steel file (hardness about 7), the point of a piece of glass (about 6), the edge of a penny (3), or a fingernail (2.5). If your 'point' is harder than the test specimen, you should feel it bite into the sample.
3. Examine the sample. Is there an etched line? Use your fingernail to feel for a scratch, since sometimes a soft material will leave a mark that looks like a scratch. If the sample is scratched, then it is softer than or equal in hardness to your test material. If the unknown was not scratched, it is harder than your tester.
4. If you are unsure of the results of the test, repeat it, using a sharp surface of the known material and a fresh surface of the unknown. 
5. Most people don't carry around examples of all ten levels of the Mohs hardness scale, but you probably have a couple of 'points' in your possession. If you can, test your specimen against other points to get a good idea of its hardness. For example, if you can't scratch it with a copper coin, you know its hardness is between 3 and 6. If you scratch your specimen with a piece of glass, you know its hardness is equal to or less than 6. Real porcelain can be scratched by quartz but not glass. 

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