Tile Information

MONOCUTTURA CERAMIC TILES

This is the most popular/widely used type of tile for most floor and wall applications depending on the mix and type of clays used, their density or degree of hardness, influence by the temperatures these are fired at.  (Monocuttra as a literal translation means a single firing).  Various mixes of clays can be used to achieve lesser or greater density of body/bisque, onto which glaze is applied.  Many finishes (Matt vs. Gloss vs. Satin/Sheen, patterns and/or slip- resistant surfaces, etc.) can be achieved during the glazing process by adding specific ingredients either onto or into the glaze.  Glazes make the surface waterproof or impervious to stains and thus are more easily cleaned and maintained.  Generally detergent soap and water is sufficient.  Glaze hardness and firing temp will determine the application of the product whether it is suitable for outdoor use, commercial or industrial applications such as shopping centers, or high traffic areas. 

PORCELAIN TILES

These tiles are extremely dense with a low degree of water absorption and very hard wearing, thus more expensive than Monocuttura Ceramic Tiles.

They are divided into 3 categories:

1. Full body unglazed – where the colours are obtained by dispersing mineral oxides throughout the bisque.  This will result in the colour being consistent throughout the body.  Water absorption is generally less than 0.5%, but need only be less than 3% to be considered nonporous or fully vitrified.  Suitable for heavy traffic areas and industrial applications.
2. Polished porcelain – as above, but the surface is polisheded with a pumice stone type material creating a gloss appearance.  Polishing the porcelain is an expensive process, which always results in polished material being more expensive than unpolished.
3. Glazed porcelain – where the tile is glazed to obtain specific finishes/effects.

Note:  When purchasing porcelain tiles, due to the density of bisque an adhesive of higher bond strength is required for laying of tiles.

Porcelain tiles, due to their density and low water absorption properties are suitable for areas in sub-zero temperatures.  Normal ceramics will absorb water, which when freezing expands, resulting in tiles "breaking up"?.   Since porcelains absorb very little moisture, they are frost resistant.

CLAY TILES (EXTRUDED OR PRESSED)

Today ceramic tile manufacturers copy the look of Terra Cotta tiles in glazed form, which do not require the regular maintenance of unglazed clay tiles or sealant application and thus are easier to clean and maintain.

SLATES AND SANDSTONES (Natural Stone Products)

GRADING OR CLASSIFICATION OF PRODUCTS

Second Grade – when the manufacturer separates the firsts out of the production run form the second grade (out of spec) and boxes the latter separately.  Various criteria combine to make up second grades:  The specifications fall outside the parameters set by European Norms, e.g. sizing variation may be greater than the 0.5% allowed, the shading/ tonality vary from the intended colour mix.  There may be small blemishes, pinholes or glazing defects or combinations thereof (patent defects).  The glaze hardness should however be the same as per first grade as the production/firing process the tiles undergo are identical.  Cost savings are between 20%-30%.

Third Grade or Rejects – defects here are much more pronounced than in second grade.  Tiles may be chipped (pieces missing) with visible shrinkage cracks and more obvious blemishes and glazing defects.  Thirds are sold at roughly half the price of firsts. 

No manufacturer will guarantee anything other than First Grade product.  Customers must familiarize themselves with the possible problems attached to purchasing Commercial, Second or Third Grade.  No claims will be entertained on anything other than First Grade products.

GENERAL

It is important to know the hardness/rating of the glazes when purchasing tiles, (i.e. P.E.I. Rating or Mohs, being the abrasion rating and hardness of glaze tests).

Tiles have esthetic properties.  They should not be subjected to abuse.  They will not "hold/hide"? construction defects.  If there is a construction crack in the slab, this will be transferred through the tile resulting in an identical crack running parallel to the slab crack.  Movement or expansion joints are therefore important. 

Floors and walls are to be properly waterproofed before tiling.  Tiles will not fix or hide any damp problems.  Cement salts/efflorescence will permeate through the tiles (such as Clay/Terra Cotta tiles) or through grouting joints, leaving white dust on the tile surface.  Technological advances in adhesives today allow one to tile on top of existing tile, as long as the base underneath is firm – a very successful practice in refurbishing.

Latex additives mixed into the grout and/or adhesives will allow for some level of flexibility and resist the growth of mould and fungi and improve water resistance.  These can also be used to give additional bond strength.  Surface preparation is as important as the tiling itself.  The background must be properly dry, dust free and prepared in the case of bitumen or previously painted surfaces.  Tiling should only commence 4 weeks after newly laid slabs or screeds or newly plastered walls, during which time the cement is curing (drying) and thereby shrinking.

Tile Tips

STEP ONE

1. Check all pallets/boxes, that were purchased was correctly invoiced & delivered or received in terms of quantity and quality.
2. Check all references on the boxes are the same with regard production dates (if there is one) as well as caliber & shading/tonality.
3. Check that sufficient product has been purchased to complete the whole job, inclusive of cuttings, breakages & waste.  The distributor cannot be held liable for shortages as new batches may have arrived or products that have been discontinued by the manufacturer between the time the tiles have been purchased & the time of the tiling job.
4. Check that the standard of product purchased is suitable for the application (e.g. PEI & MOH’s).  Wall tiles not to be laid onto floors.  Domestic type products not to be used on high traffic areas.  Porous products not to be used in areas where there is frost or freezing conditions.
5. Allow an appropriate curing/drying timer for "green"? cement screeds, plastered walls or slabs before tiling can commence.  28 days is generally the accepted period after cement has been laid.
6.Check that there is sufficient lightning on site as SABS specification 0107.1996-Parra 7.2.7.

STEP TWO

1. Open 7 to 10 boxes randomly (not necessarily all from one pallet) & check for physical/patent/obvious defects.
2. Check that all tiles conform to norms/standards/specifications (e.g. SABS, DIN, E Norms etc) with regard to skew ness, warping, size variation, dishing or bowing (only applicable to 1st grade products).
3. Check if colour/tonality is an acceptable mix before fixing as no claims will be entertained if tiles have been laid/fixed – these will have been deemed acceptable to lay by the professional tiler or purchaser.
4. Check that 95% of each square metre of tile has no visible defects from approx. 1.0 metre high above ground level where tiles have been randomly/loosely laid out for inspection.
5. If all checks have been carried out correctly & found acceptable standards apply, only then should tiling commence.

STEP THREE

1. Plan tiling and lay out carefully, check where there are, or should be, movement and expansion joints.  Check where the cuttings should be (in less conspicuous places).  Check vertical & horizontal levels of walls & floors for straightness.
2. Prepare the floor properly for either mortar or adhesive fixing methods (as per manufacturer’s instructions or SABS 0107.1996 Code of Practices).  Ensure no contaminates exist on surfaces to be tiled that will prevent proper adhesives are used – porcelain or fully vitrified tile require more bond strength than semi-vitrified or non-vitrified tiles.
3. Use skilled tillers, fixers using appropriate cutting & laying tools – these may differ to the type of product being laid & thickness thereof (ceramics vs. terra cotta vs. natural stones/slates, etc).
4. Do not use "spot method"? of tiling while using adhesives or mortar.
5. Do not walk on tiles during curing/drying process – this will cause irregular movement of tiles causing irregular line & surface finish.
6. Do not lay 1st grade tiles with obvious defects such as cooling crack or blemishes.

STEP FOUR

1. Allow sufficient time after fixing tiles for the drying process of mortar adhesive fix, before grouting, allowing for possible efflorescence.
2. Clean floor & walls thoroughly continuously during tiling & immediately after grouting.
3. Ensure floors are protected from sand or abrasive materials (such as cement residue from either mortar or grouts) as well as heavy machinery and construction damage after tiling & before handover of total completed job.
4. Check that correct cleaning materials are used. Some acids can damage the tiled surfaces. 
5. Ensure correct maintenance of floors to ensure long usage thereof. 

Tile Information

TRAVERTINE

Dense, banded rock composed of calcium carbonate, CaCO3.  Formed by rapid chemical precipitation of calcium carbonate from solution in surface and ground waters, it is a variety of limestone that has a light colour and takes a good polish.  Also known as "Travertine Limestone"? or "Travertine Marble"? they are characterized by winding irregular holes in the surface, with the flats finished to varying degrees of smoothness and reflectivity.

Travertine can be bought in its natural form, i.e. with holes in the surface and polished, or honed, or it may be purchased "filled and honed"?.  In the latter case the surface holes are filled with coloured epoxy or a coloured cementious compound and the tile is then polished and honed to obtain a shiny surface.  Tiles can be purchased in a wide variety of sizes as the tiles are cut from very large blocks mined from the earth.

Travertine can be laid with very small "grout gaps"? or even butt jointed as they will not expand over time as is the case with ceramic tiles  Butt jointing is not recommended however, as bacteria will become lodged in the cracks from mopping etc.  It is best laid with a 1.5mm to 3mm joint.  However normal good tiling practice must be followed at all times and the expansion joints in the slab must be followed through the surface.  Normal tile adhesive may be used for fixing of the product.

Travertine scratches easily so it requires a great deal of care to keep it looking great.  The leather or rubber on the soles of shoes can hardly scratch it.  Scratches only occur when sand and grit are present on the floor and are ground in by the soles of shoes.  So, the first and most important rule to properly maintain a polished stone floor is to keep it as clean as possible all the time.  Vacuum it at least once a day and mop it at least once a week.  It is most important to have "walk off"? mats at all entrances, and these must be shaken out and cleaned at least once a week, and daily in high traffic areas.  The products used to mop the floor must be ph neutral.  Acid or alkali products will adversely affect the look of the tile over time.

Travertine is considered as a compact limestone, therefore its crystals won’t "stun"?.  Only true geological marbles (metamorphic limestone) do that.  Therefore deep scratches can be easily eliminated by a heavy honing action (wet-sanding technique).  With regard to sealing of the product.  The stone is naturally quite dense and, as a general, unopposed and quite sensible rule, the more you leave the stone alone (in its natural state, that is) the better it is for it.  However, applications may vary widely and so does the quality of travertine and so it is essential that one consults an expert in this regard, both to recommend a good stone sealer, if necessary, and to find out if sealing really is necessary.

POLISHED PORCELAIN TILE

This porcelain has become very popular of late, with it’s high gloss finish it reflects light well, and new technology has allowed a great deal of fantastic styles and designs to be produced.  Porcelain is a ceramic tile with an absorption rate of 0.5% or less.  There are various types of porcelains:

NATURAL PORCELAIN TILE

A.k.a. "technical porcelain"?, "unglazed porcelain"?, "unpolished porcelain"?, or "through-body porcelain"?.  Natural porcelain is, as the name implies, porcelain that has not been glazed nor polished.  These tiles are made of porcelain through and through.  They can have surface treatments (soluble salts), have a different face and body (double loaded), or the face of the tile simply be different color or texture than the body of the tile, yet it’s still classified as through-body "natural"? porcelain.  Absorption has nothing to do with the facial surface being stain resistant.  Unless the tile manufacturer has treated the porcelain to close up the surface (micro) porosity, you’ll need to seal natural porcelain tile before grouting.

POLISHED PORCELAIN TILE

Polished porcelain is natural porcelain with a polished surface.  The polished surface isn’t a glaze, but actually comes within the stone and it’s polished in a fashion similar to granite.  It’s important to note that the polishing process on a porcelain tile actually opens up the pores of the tile.  This means polished porcelain tiles must have a penetrating or impregnating sealer. 

GLAZED PORCELAIN TILE

Many glazed porcelains are right at .5% absorption.  However, if the bisque (clay body) of the tile is used as part of the visual design on the face of the tile the absorption should be under .1%.  Glazed porcelain can be partially glazed, they can use glaze elements used in the manufacturing process or they can be completely glazed.  There are even some glazes that can be polished!

Any type of porcelain tile has the following benefits when used residentially:

Chip resistance

Through-body colour porcelain tiles offer chip resistance in two ways.  First, porcelain tiles have high mechanical strength and are extremely chip resistant.  Second, if a through-body colour porcelain tile does chip, the chip is the same colour as the tile, so it doesn’t have to be replaced (unless the homeowner insists).

Wear resistant

Natural porcelain is simply the hardest, most durable surface for high foot traffic installations.  In floor areas in malls, grocery stores or banks, you just can’t beat the durability and beauty of natural porcelain.

Chemical resistant

All porcelain tiles are going to be much more resistant against citric acid, wine, mustard and other household chemicals than virtually any type of natural stone, including granite.  This makes porcelain an ideal choice for kitchen counters and floors.

Cost

You can buy porcelain for less than natural stone; however, there are many porcelain tiles that will cost more than natural stone.  However, keep in mind, that most porcelain tiles are technically superior overall to granite (the hardest of all natural stones) and many are virtually identical in appearance to natural stone.

ADVANTAGES AND DISADVANTAGES OF NATURAL STONE

Natural stone tiles are distinct and unique.
You should always view several pieces of the tile that is to be installed before the installation begins.  Since it has been created by nature, not only are no two pieces exactly alike, those two pieces may not even be very similar.

The most common natural stone tiles include:
Slate, sandstone, marble, granite, travertine and limestone.  Each stone has unique characteristics and maintenance requirements.

Generally, you should seal natural stone tile before grouting, unless you are planning on using the grout color in the stone as a design element.

MOST NATURAL STONES ARE NOT RESISTANT AGAINST COMMON HOUSEHOLD ACIDS (LIKE LEMON JUICE) OR OIL STAINS.
Therefore, you should use a penetrating sealer for all natural stones after installation.  Follow manufacturers instructions on frequency of re-application.

THE ADVANTAGES OF NATURAL STONE

• Timeless, unique appearance
• Design capabilities of through-body color material
• Perceived value
• Durable countertops and floors (granite)
• May be re-polished if scratched

THE DISADVANTAGES OF NATURAL STONE

• Ongoing re-sealing program is required
• Limited chemical and stain resistance
• Higher installation costs than ceramic tile
• Product received seldom looks like the sample