New & Traditional Countertop Choices: Part 1 Natural Stone Ceramic Tile Porcelain Slab/Sintered Stone Metal Wood Glass
A countertop takes a lot of abuse. In the kitchen, you put hot pans on it, cut on it, scrape and scratch at it, scour it, and spill hot liquids on it. In the bathroom, it's worse — with all the various chemicals spilled on counter surfaces — the soaps, the creams, the nail polish, the model airplane glue. Yet after years of abuse, your countertop is expected to look as good as ever — and mostly they do.
The engineers at Consumers Union seem to test and rate just about everything in the world.
We rely on their published ratings to buy vehicles and tools, But we don't always agree with their conclusions about kitchen and bath materials and fittings, for the simple reason that they are contrary to our experience, which is fairly extensive.
For example, a recent "Kitchen Planning and Buying Guide" suggests that sinks can be undermounted only under expensive countertops like solid surfacing, stone, and engineered surfaces. We know of at least one sink that can be mounted under laminates. Consumer Reports seems not to be aware of it.
But most of the things they say strike us as being right on the mark. We agree almost completely with their take on countertop materials. Here are their top five ranked countertops based on extensive testing of various materials. We would reverse the rankings for tile and granite, placing tile above granite. We think Consumer Reports did not take into account the new stain-resistant urethane and epoxy grouts when evaluating tile countertops.
The numbers appearing in parentheses are Consumer Reports' score for the material, out of 100 possible points.
Engineered Quartz (87)
But edges and corners can chip, although rounded edges help. Stone finishes can appear too uniform and, therefore, less natural.
Price $50-$100 per square foot, installed. $2,800 to $5,600 for an average-sized kitchen.
Best For a natural stone look that can withstand heavy use. It resists stains when it's properly sealed, and also resists heat and scratches.
But granite needs sealing to protect it from stains. Color and grain can differ from samples.
Price $45 to $200 per square foot, installed. $2,500 to $11.200 for an average kitchen.
Tile (Ceramic or Porcelain) (76)
Best for use near stoves because it is heat resistant. Comes in many colors, patterns, and prices.
But it chips and the grout between tiles stains even when sealed. Poor installation can increase these problems. Thinner grout lines and darker grout might help. (Editor's Note: Consumer Reports appears to be unaware of epoxy and urethane grouts that are not cement based and do not stain.)
Price $10 to $30 per square foot, installed. $550 to $1,700 for an average size kitchen.
Best for variety and budget-friendly price. It's excellent at resisting stains and heat damage and is simple to install.
But It's easily scratched and isn't repairable. Shows seams, though post-formed (seamless) options are available.
Price $10 to $30 per square foot, installed. $550 to $1,700 for an average-sized kitchen.
Solid Surfacing (49)
Best for seamless installations. Many colors and styles are available, such as those that mimic concrete, stone, and quartz. It's non-porous and stain resistant. Small nicks and scratches can be repaired.
But it scratches easily. Stone-look finishes can appear more uniform than natural.
Price $35 to $100 per square foot, installed. $1,950 to $5,600 for an average-sized kitchen.
For more good reading, check out our complete articles index.
Today's countertop materials are truly miracles of modern engineering, evolving so rapidly that even if you've replaced a kitchen countertop in the recent past, you'll probably be surprised by the many options in materials and styles now available.
There are very few materials more durable than stone. Cool and long-lasting, stone offers a timeless, elegant beauty that few other materials can match.
Natural Stone Pros, Cons & Ratings
Pros: Sinks can be undermounted and some stones can handle hot pans (but some cannot so be careful) Many suppliers of soapstone, marble, and travertine can also provide matching sinks.
The material is available in a great many colors and patterns.
Cons: All natural stones except soapstone and some slates are to some degree porous and require periodic sealing, usually once a month.
Soapstone and some slates are non-porous and can withstand staining without being sealed. Porous stones like granite, marble, limestone and travertine stain and show watermarks if spills are not immediately wiped up. The calcium-based stones, marble, travertine, and limestone, are very susceptible to damage by even mild acids in food and liquids such as vinegar or citrus juice.
Any stone can be scratched, but with hard stones like granite and slate, it takes quite a bit of effort. Soapstone is very easily stained, even by water. However, all but the deepest scratches and stains can be buffed out with a ScotchBrite pad.
Seams between highly figured slabs can be very evident. Stone, especially granite, can contain natural fissures that look like cracks. These are harmless but many homeowners do not like the look.
Out of 10
Durability - High: Stone is a 100-year material with proper care.
Some stones are more durable than others, however. The calcium-based stones, marble, travertine, and limestone, can be damaged by mild acids, and most stones will show effects from placing hot pans on them.
All are susceptible to edge chipping, slate most of all, which can be cured in most instances by rounding the edge. However, as a rule, it takes a fairly determined effort to damage a stone countertop, and most damage can be repaired invisibly.
Maintenance - Medium: All stone, with the exception of soapstone and some slate, needs periodic sealing. Spills should be cleaned up right away, especially with calcium-based stones that can stain easily. Soap and warm water for daily cleanup.
Cost - High: Stone is one of the more costly materials. Only a few engineered materials and the metals cost more than natural stone.
Green - High: Stone is not renewable, we can't make any more of it. But, it is sustainable. We are not going to run out of it ever.
We don't actually use up the stone in making a countertop. In a countertop, stone is still stone. It has not been converted to something else. When its useful life as a countertop is done it remains stone however it is disposed of. In a sense, we are merely borrowing stone to use as a countertop temporarily then returning it to its natural state when we're finished, although in a new location.
Stone does not require much in the way of fabrication and uses little energy compared to the manufacture of other countertop materials.
Some stones are hard and resist scratches and heat, Others are more delicate and require a lot of care and maintenance. Even the most durable stone has drawbacks as a countertop material. It has no "give" at all so that a plate, cup or glass dropped on it is likely to shatter rather than bounce.
The stone itself can crack, break, chip and scratch. Some stones stain easily — marble, travertine, and soapstone are notorious culprits — although many believe that the visible signs of use that accumulate over time add to the patina and charm of these upscale materials.
Slate and schist are particularly susceptible to edge chipping and require special care in both installation and daily use. But, all stones will chip if hit hard enough or at just the wrong angle.
Almost any stone can be made into a countertop but the most desirable stones are those that can take a good polish to create a smooth working countertop surface.
We are not even going to try to review all of the possible stone countertops. There are far too many. We will look at just the more common offerings in regular commercial use: granite, limestone, marble, schist, slate, and travertine.
Marble & Travertine
Travertine is very like marble, just more porous and softer. Both materials have been popular since the early Greek and Roman years because they are beautiful and fairly soft, making them easy to cut and polish with relatively simple hand tools (and a whole lot of hard labor).
Frequent cleaning and re-sealing are needed to keep the materials looking new. They can be dulled by soap scum and hard water and will show white rings if wet glasses are left on the countertop for too long.
Granite is still the stone of choice these days. It is heavy, hard and durable, very difficult to crack or chip and will easily outlast your house.
Many varieties are very had to stain, but regular sealing is usually recommended. We have heard reports of granite tops that do not need sealing, but we have never actually seen one, and, frankly, don't believe it. Granite, no matter how dense, is porous and any porous material can stain.
Granite comes in a seemingly infinite range of colors and patterns, with more arriving every day. On the downside, it is just about the most expensive countertop material around, rivaled only by concrete and some engineered stone materials.
Soapstone, eclipsed for years by granite for most of the last two decades, is making a strong comeback as granite countertops become more and more common.
The look of soapstone is timeless and historically accurate for almost any period of American architecture. It is warmer, denser and heavier than granite.
Unlike granite and most of the other natural stones, soapstone is almost impervious to water penetration, unaffected by acids or other kitchen chemicals, and absolutely heat resistant.
Classic soapstone from New England is light gray to almost black, often with a greenish tinge, but the material can range from light brown to terracotta depending on its source and treatment. Very little soapstone is now quarried in the U.S. Most comes from Brazil.
A soapstone surface darkens naturally with age or when exposed to water or oils. To darken it evenly, soapstone can be treated with food-grade mineral oil. The darker it gets, the more light grey or gray-green veins stand out adding to soapstone's appeal. New "dry wax" coatings have been developed that replace mineral oil and last longer, but are, of course, considerably more expensive. Many soapstone fans, however, simply let it age naturally over the years, adding a patina of wear and use. But, renewing soapstone is easy — simply sand away the old surface for a brand new look. Repeated restorations are possible over many years.
Limestone is another sedimentary rock composed mostly of calcite. Like marble and travertine, Limestone is very soft and easy to damage with acids and abrasion. The most frequently used limestone for countertops is dense and fine-grained. Examples are Jerusalem stone that is known for its consistent texture and even color and Belgian and French bluestone.
Limestone is available in the usual earth colors: brown, beige, yellow, gray, and black. The bluestones have a bluish tint, which makes the rare and sought-after. Look for consistency in color and even texture throughout the stone. Some limestones are dense enough to be polished to a high gleam, but the usual finish is a low luster, hewn stone look.
The stone is soft and porous. It retains moisture and can stain irreparably. Like marble and travertine, it can be damaged by mild household acids like lemon juice, vinegar, and tomatoes which can dissolve the calcium in the stone. It can also be easily scratched and is not usually recommended for busy working surfaces such as in food preparation areas, or any place a knife is likely to be used. But as an accent countertop or backsplash, it can be truly gorgeous.
Slate and Schist
Most true slate is used for floors, usually in the form of tiles. It is too soft for countertops.
The material actually used in most "slate" countertops is schist, a. harder, finder grained metamorphic rock quarried mostly in New England and upstate New York.
Schist is dense and like soapstone, nonporous. Liquids cannot penetrate the surface of the stone, so it will not stain. It contains little calcium, so it is unaffected by acidic liquids like wine and fruit juices. Hot pans can be placed on it without risk of damage.
It comes in an array of earthtone colors: light gray to charcoal, various shades of purple and green and soft red in naturally streaked and plain patterns. Stylistically it is a more subdued option for countertops. It does not have the dramatic grain and color effects of granite. For reproducing a heritage kitchen, however, it is authentic and consistent with any era from early Victorian to the present.Maintenance is minimal. A wipe-down with a damp cloth or sponge is usually sufficient with an occasional cleaning with a mild detergent. While the material does not need sealing, some owners wax or oil the surface to give it a wet look that deepens the color and enhances any grain effect.
Slate is brittle. It can be chipped at corners fairly easily, so most installers round off corners to reduce the risk. A sharp blow from a heavy object such as a cast iron skillet can crack the material.
If any countertop material is available in even more colors and patterns than laminates like Formica®, it must be fired clay tile.
Glazed Ceramic Tile Pros, Cons & Ratings
Natural stone tile and unglazed ceramic tile have all the advantages and drawbacks of natural stone countertops (except the hefty price), and should be treated as stone (see above).
Pros: Comes in nearly an infinite variety of colors and styles. Can be as inexpensive as laminates.
Glazed tile is extremely durable. It resists heat and moisture, and cannot be cut. Any damaged tile can be readily replaced, provided you kept a couple of spare tiles, just in case.
Cons: Glazed tile can be scratched and chipped (especially at outside corners) but only by the truly determined.
Traditional cement-based grout can stain and may be hard to keep clean. However, narrow grout lines and new stain-resistant urethane and epoxy grouts have virtually eliminated this problem.
Must be installed by a professional or very skilled do-it-yourselfer. Like stone, engineered composites and concrete, tile is very hard, so any dishware dropped on it will probably break.
Out of 10
Durability - High: Care must be taken to select the proper grade of tile for a countertop (see: Porcelain vs. Ceramic Tile, Is There a difference?), but a tile rated for countertops will last a very long time and keep its like-new appearance after a lifetime of use. Immune to household chemicals, heat, and most impact damage. It can be chipped at the edges, but it takes determination. The only material other than metal, that a hot pan cannot damage.
Maintenance - Very Low: Requires no sealing or other periodic maintenance if a modern, non-cement-based grout is used. Cleans with soap and water.
Cost - Varies: Ceramic tile is both the least costly and most costly material available. Suitable tile can be purchased on sale for one or two dollars a square foot, but hand-made artisan tile can run hundreds of dollars, some even thousands of dollars, per square foot. The labor to install the tile can be costly, and doing it yourself is not an option for any but the most experienced DIY-er.
Green - High: The basic materials used are clay and sand, both of which are sustainable. We are not likely to run out of either very soon. Only minimal fabrication required. No toxic materials or possibility of out-gassing. However, a lot of electricity or natural gas is required to fire the kilns it is cooked in at up to 2,200° Fahrenheit.
Tile for countertops has an impressive history going back to the ancient Greeks and Persians, even farther. To give you an idea of the durability of tile: Tile work in the Roman city of Pompeii was complex and intricate, survived one volcanic eruption and has lasted for 2,000 years. And, by today's standards, it is not even very good tile.
Ceramic tile is made from a special clay called kaolin and silica (sand). Clay tiles are "fired" — heated in a kiln to a very high temperature to harden the kaolin and turn the silica into quartz glass.
High-quality water- and wear-resistant tile is fired longer at a higher temperature so it is harder, denser and more impervious to water than "softer" tiles.
A glazed tile has been surface coated on the top side with glass which bonds to the clay when the materials are fired. Tiles may be glazed or unglazed. Unglazed tile must be treated like stone. It must be sealed, and the sealant must be renewed every year or so.
Glazed tile may be treated like glass — a surface that needs almost no maintenance. Unlike glass, however, tile is very difficult to break.
Caring for Cement Grout
If your tile countertop is more than a few years old, then the grout is one of the old cement-based blends. These require a lot of maintenance. But, it's not an impossible task. Here's how to keep cement grout looking fresh for a long time.
- Never use chlorine bleach, muriatic acid, vinegar, or other caustic chemicals unless the label indicates that it is safe for grout. These can deteriorate and etch the grout, making it more of a dirt magnet.
- Try our proven home-made recipe, 1 or a mild acid cleaner formulated specifically for tile and grout. After a thorough cleaning (with a brush) and rinsing, re-seal the dry grout with a deep penetrating sealer.
- For badly stained grout, there is an alternative. After washing grout with an approved grout cleaner and rinsing it thoroughly, use a toothbrush to apply a grout colorant. 2 It can be mixed to match almost any colored or white grout, and most of these products seal as they color.
- If all else fails, call a cleaning service that specializes in tile restoration. They're in the Yellow Pages.
If you want to avoid the grout staining problem altogether, order your tile with urethane or epoxy grout. Unlike cement-based grouts, these grout products are almost stain proof, remain flexible so they seldom crack or split, and do not ever need to be sealed.
Not every tile is suitable for use as a countertop. Soft, thin tiles designed to use on walls are not good countertop material. Hard tiles rated for use as flooring are more than adequate.
Grout is a problem for a lot of people who otherwise think tile would make a beautiful surface for countertops. Everyone has heard the stories: grout cracks, falls out, stains, gets dirty, harbors harmful bacteria and needs to be cleaned and sealed regularly. All of this is true with cement-based grouts. But there are other kinds of grout.
Epoxy grouts are nearly crack and stain resistant. They have been available for years but are seldom used outside of commercial buildings. Their problem is that they are expensive, difficult to apply and very unforgiving of mistakes. Some tilers won't use them at all.
Of more recent vintage are urethane grouts. Urethane is a polymer, essentially a tough plastic, flexible and very stain-resistant. It will last nearly as long as your tile and, best of all, does not need to be sealed — ever.
Its one drawback is that it has to cure for up to 72 hours before being used (7 days around a sink), which can be a nuisance. It is also more expensive than cement-based grouts. But we think the extra expense is worth the saving in maintenance over the years. You have to specify urethane, otherwise, your tile installer will probably use the older, cement-based, formulation.
It is also possible to lay tile without grout. The edges are butted together, a process called
close-setting. Ordinary tile may be close in finished size but is almost never exact due to the way the firing process shrinks tile unevenly. So, a grout line between tiles is normally required even if the grout line is a very narrow 1/16" or so. Close-setting requires a special "rectified" tile that has been cut or ground so that each tile is exactly the same size.
Glazed tiles are already permanently sealed with glass so sealing is not required. Urethane and epoxy grout does not need to be sealed. But, cement-based grout lines must be re-sealed periodically even in glazed tile. Grout and tile sealant is nothing more than a special coating containing a high percentage of silicon. It is usually applied with a brush or sponge and wiped off with a soft cloth. Nothing to it, really. It's not the sealing that is burdensome, its the cleaning and de-staining before the sealing that people do not like.
The cost of tile ranges so widely that it is both the least expensive and most expensive countertop material. Some specialized imported tiles cost hundreds of dollars per square foot. Yet you can buy perfectly acceptable tile on sale from time to time for $1.50 s/f. So it is possible for a customer on a budget to use tile -- just stay away from anything made in France or Italy.
Porcelain Slab and Sintered Stone
Porcelain slab and sintered stone are not new materials. In fact, they are very old materials in a new form — nothing more than exotic than ceramic tile in a new, larger format. Porcelain slabs are typically sold by its makers as super-sized tile. Sintered stone manufacturers are more likely to describe their material as an artificial stone and are less likely to glaze the material. It is not stone, however. It is a ceramic made from clay, more akin to a brick than it is to rock.
Tile makers have been experimenting with larger format tiles for decades. Tile in larger sizes is hard to manufacture because the material tends to cup, curl and twist when it is fired at temperatures of up to 2,500°. The larger the format, the more the cup, curl and twist is evident.
But, by adjusting the tile mix, using less water and special additives, and varying the temperature and firing times, tile makers perfected the flat 12" x 24" tiles that generated a renewed interest in tile countertops in the 1990s since grout lines could be minimized using the larger format tile.
In the early 21st century even larger tiles were created — up to 48" formats — which made possible the faux wood strip tiles now popular to replace of strip wood flooring in kitchens, baths, and mudrooms with more durable ceramic tile without sacrificing the wood look.
Now ceramic tile has gotten so large that a single tile can cover an entire countertop, eliminating grout lines altogether.
A tile that large is, of course, no longer a tile. In the industry very large format tiles are called slabs, sheets or veneers depending on the thickness of the material.
Early slabs were indeed slabs, up to 3/4" thick, heavy and very expensive. As the technology of firing large formats improved, the material got thinner. Slabs are now available as thin as 1/8" (3mm). These are more properly "veneers".
More typical, however, are 1/4" (5.6mm) slabs — the thickness of ordinary floor tile. They are called "thin slabs" or "sheets".
At what point a sheet becomes a slab is not all that clear. At one-eighth inch or thinner, the material is probably a veneer. Above 1/8" to about 3/8" the material is likely a sheet. Over 1/2" the material is structurally rigid and more properly a slab. Between 3/8" and 1/2" is anybody's guess, but
thin slab seems appropriate. Nomenclature varies from manufacturer to manufacturer, however, and somewhat according to location. So my
thin slab may be the other guy's
sheet and my
Very large format ceramics are available in up to 12' lengths and as wide as 5' — and getting still larger as the technology continues to be perfected. Five feet wide is about the limit right now, however, until larger kilns are built that can handle wider tiles.
Veneers and sheets have no structural strength and are intended to be installed over a plywood substrate just like laminate materials such as Formica®. The sheets are bonded to the substrate with a modified thinset adhesive like the stuff used to set ceramic tile. The strength of the assembly is provided by the substrate under the slabs. The thin slabs and veneers are merely the finished surface.
Porcelain Slab & Sintered Stone Pros, Cons & Ratings
Pros: Available in an increasing but still limited variety of colors and patterns. Seamless installation gets rid of the grout lines in smaller format tiles that are troubling to some homeowners. No maintenance is required other than wiping up spills with a damp cloth or sponge.
Very durable. If glazed, it is as durable as glazed ceramic tile. The surface is impervious to water and does not need to be sealed. Virtually immune to heat.
If unglazed, it is not a stain- or heat-resistant and may show a color change if a hot pan is placed on it. Unglazed material normally sealed at the factory and does not need to be sealed again. However, the seal coat is not a stain-resistant as glazing.
Cons: The surface can be scratched but only with a determined effort. Must be installed by a professional experienced with installing porcelain slabs. DIY installation is not recommended for even a very skilled do-it-yourselfer.
Will chip or crack if hit hard enough but damage is unlikely in ordinary use. Like stone, engineered composites and concrete, it is very hard, so any dishware dropped on it will probably break.
Both materials are costly, about $100 per s/f for a thin slab and about twice that for the 3/4" slab. Labor to install the material is also costly, generally higher than the cost of installing ceramic tile or a stone countertop. However, the cost is coming down as more installers get familiar with the materials.
Out of 10
Durability - High: A porcelain slab will last a very long time and keep its like-new appearance after a lifetime of use. It is immune to household chemicals, heat and most impact damage. It can be chipped at the edges but it takes determination. The only material other than metal and ceramic tile, that a hot pan cannot damage.
Maintenance - Very Low: Requires no sealing or other routine maintenance. Spills wipe p with a sponge, cloth or paper towel. Cleans with soap and water.
Cost - Very High: The material costs more than a premium stone countertop. The cost of installation is usually higher than for tile or a stone countertop installation, and doing it yourself is not an option.
Green - High: The basic materials used are clay and sand, both of which are sustainable. We are not likely to run out of either very soon. Only minimal fabrication required. No toxic materials or possibility of out-gassing. However, a lot of electricity or natural gas is required to fire the kilns it is cooked in at up to 2,200° Fahrenheit.
Some manufacturers back their sheets and veneers with fiberglass to make them less likely to crack in handling and some sheets are made with additives that leave them somewhat flexible. Some can even be bent around gentle curves without cracking, which increases their design potential.
Like glazed ceramic tile, porcelain slabs can be top-coated with a glass glaze which bonds to the clay when the materials are fired. It is impervious to liquids and unfazed by even the hottest pan (although every manufacturer recommends against putting hot pans on their porcelain slabs). The glazed surface needs almost no maintenance. The surface is very hard to scratch or mar. It is very difficult to chip or crack but if damaged, it cannot be repaired.
Unglazed slabs are somewhat porous and are sealed at the factory to resist staining. All slab manufacturers claim that the sealed unglazed material never needs sealing, but we take that with a fair-sized grain of salt.
The material is dense and minimally porous but it is not pore-free. Any porous material can stain. And "never" is a long time. The material has no track records proving that it does not eventually need to be resealed from time to time.
Slabs can be made in almost any pattern and color. Some even emulate metal. But, pattern-less and simulated stone seems to be the most popular looks. Thicker slabs can be made with patterns that go all the way through the material. This means that any veining or stone pattern continues over the edge, making it look more like real stone.
In thinner sheets, the pattern is applied only to the surface and the material requires some sort of edge treatment, of which there are many.
A porcelain slab can be an excellent choice to get the look of a more fragile stone like marble, travertine or limestone without the maintenance these stones require. In addition, unlike these calcareous stones, slabs shrug off acids, even strong acids, without damage, and cannot be scratched except with a determined effort. The calcareous stones can hardly avoid being scratched.
The difference between sintered stone and porcelain slab is that there is very little, if any, difference between sintered stone and porcelain slab.
Sintered stone is, like porcelain slabs, nothing more innovative or exotic than large-format ceramic tile. It is, in reality, just porcelain slab by another name.
But, that has not stopped sintered stone manufacturers from hyping the material as "new and innovative" and the latest and greatest
technological advancement in countertop surfaces — a step up from porcelain slabs.
According to one authority, what makes sintered stone better than porcelain slabs is the careful choice of "natural materials" that go into sintered stone:
First are granite minerals such as quartz and feldspars, which are used to provide hardness and strength. Second are silica and glass minerals, which add chemical stability. Third are clay minerals, which contribute adhesive properties and whiteness. Fourth, in order to create different colors or chromatic properties in the final product, natural mineral pigments of different types can be used.
Another adherent suggests that it is the manufacturing process that distinguishes sintered stone from porcelain slabs.
Sintered stone is manufactured using recent technological advancements which mimic the processes which form natural stone… Minerals … are … subject[ed] to extreme heat and pressure, just like they would be deep in the earth's crust where granite is formed. When the process is finished, the particles are bonded together permanently, without the need for resins or bonding agents.
In fact, absolutely nothing here is new or could be considered a "technological advancement".
The manufacturing process that mimics the
extreme heat and pressure that form natural stone is the well-established dust-press (or dry-press) method of making ceramic tile. It has been around since 1853 when it was patented in England by Richard Prosser.
The "natural" materials are the tried and true ingredients that have been used to make ceramic tile since the Stone Age — more than 5,000 years and possibly as long 10,000 years ago. So, again, nothing new here.
What is new is that the chemistry of preparing the materials has gotten more precise, the presses have gotten larger and more powerful, and kilns have gotten hotter. But, as far as an actual technological break-through, there are none.
The dust-press process of forming ceramic tile is an alternative to the more common extrusion method. It is increasingly being adopted by tile makers because it produces more consistently even tile. It is also faster and less costly than extrusion.
The tile starts out as a slurry of kaolin clay, feldspar, silica (sand), quartz and any additives the manufacturer believes will make a better tile. The slurry is about 30% water. The mixture is called the "slip" or "body slip".
Once the materials are well mixed the slip is placed in a dryer to remove most of the water. At this point, the slip is a slightly moist powder that can be stored until needed.
To make tile, a porcelain slab or a sintered stone panel, the powder is pressed in a mold at a very high pressure to compact the material and form what is called a bisque. The pressing removes almost all remaining water and any air or gas trapped in the material. The bisque is now very dense and compacted.
Next, it is dried again to remove all but a trace of moisture. The water has done its job, helping the particles stick together. It is now no longer needed.
The bisque or "green tile" is fired for as long as 24 hours in a kiln at about 2,500° Fahrenheit (1,371.1 degrees Celsius) — a temperature at which the clay and feldspar in the bisque soften and begin to bond together to produce mullite (or porcelainite).
This process of softening a material so it begins to bond without turning it into a liquid state is called "sintering". The resulting bond is at a molecular level and is very strong.
At about the same time that sintering begins, the silica in the mix bonds with oxygen to turn into cristobalite, a form of quartz (silicon dioxide) that flows into the gaps in the mullite, sealing the material so water and other liquids cannot penetrate. This process is called vitrification.
Mullite gives ceramic material its strength. Vitrification makes it stain- and water-resistant. How resistant depends on how much vitrification occurs. If vitrification is almost complete the material is considered impervious to water using a rating system in common use in the tile industry.
So, when all the hype is stripped away, despite the word "stone" in its name, sintered stone turns out to be not a stone at all — not even a stone composite. It is nothing more innovative than a high-quality large format ceramic tile. A more accurate description would be "sintered clay". But, who would buy sintered clay? Sintered stone is much sexier.
Sintered stone is available in widths up to 5' and lengths up to 12', just like porcelain slabs.
Also, like porcelain slabs, Sintered stone is available in several thicknesses down to about 1/4". A variety of colors is available, some without a pattern but many that simulate stone, especially marble. In fact, if you are thinking natural marble for your kitchen or bath, take a good look at porcelain slab or sintered stone. For about the same cost you will get a material that is much more durable and virtually maintenance-free.
One difference between the materials that we did notice is that makers of porcelain slabs are more likely to produce the material with a glazed top, while sintered stone makers seem to prefer unglazed, more in keeping with the illusion that the material is actual stone.
For more information about the difference between porcelain and other ceramic tile, and details of how tile (including porcelain slabs and sintered stone) is made, see Porcelain vs. Ceramic. Is There a Difference? and How to Choose Ceramic Tile.
The common use of metal sheets for countertops dates back almost to the middle of the 19th century when zinc and later porcelainized steel began to replace wood and stone as work surface materials in bars and restaurants and later in private residences. Porcelainized steel (a steel sheet enameled with a glazing) was popular as a table-top material right up to the 1960s and is one of the icons of Post-war mid-century modern kitchens. (See Post-war Housing Styles: Cape Cod, Colonial, and Ranch for more information.)
Zinc is still used today but has been largely replaced in restaurants and commercial kitchens by stainless steel. Copper is a popular metal for countertops in home kitchens, although it is can be a maintenance-intensive material and a high-dollar investment.
For the quintessential industrial look, nothing surpasses stainless steel countertops.
Metals Pros, Cons & Ratings
Pros: Water-proof, seamless, resists staining, nearly indestructible. Cannot be burned.
Copper is timeless and fits almost any decor. Zinc fits any decor from Victorian through Post-War modern. Stainless is most suitable for very contemporary decors.
Cons: Very costly — starting at about $150.00 per square foot, not including installation. Stainless is very industrial and suitable primarily for ultra-modern and Euro-style decor.
Copper is maintenance intensive unless it is just allowed to succumb to its natural tarnished state. Zinc will oxidize, and eventually turn a pewter color but it will take a few years. Various methods are available to artificially "age" either metal giving it the patina of a countertop that has seen decades of use.
Out of 10
Durability - Very High Virtually indestructible. Will scratch but the scratches can be polished out periodically if desired. Cannot be burned. It can dent but it takes work. One-hundred-year (plus) materials.
Copper, if not polished, will tarnish to a gray-green color called Verdigris. Zinc will oxidize to a mottled gray patina. Trying to stop or retard these natural processes is a maintenance nightmare, and not recommended. Stainless will not rust or tarnish (actually it does rust but very, very slowly).
Maintenance - Very Low: Requires no sealing or other periodic maintenance. Cleans with soap and water.
Cost - Very High: Some of the most expensive countertop materials. Probably not for the budget-minded.
Green - High: Metals require smelting, which is an energy intensive process. On the other hand, a countertop does not actually require much metal. Most of it is the wood-product backing which is itself a relatively eco-friendly material consisting of wood chips and fibers that would otherwise be discarded. All of these metals are very reusable and recyclable.
Stainless is widely used in commercial and industrial applications because it just may be the almost perfect countertop material.
It is impervious to moisture; seamless so there are no cracks for dirt and bacteria to hide in; very resistant to staining and discoloration; unbreakable (in fact, it is nearly indestructible).
It cannot be burned or cut. It takes a serious effort to dent the thick sheet of stainless used in most installations. It never fades, molds, or rusts. So why doesn't everyone use it?
Many people (especially those with less-than-fond memories of the high school cafeteria) think it's just plain ugly. It is the epitome of the institutional food service look. In fact, the companies that install stainless in your home are also likely to be the ones that did your employee cafeteria, the local Arby's and the state prison. And, it is very expensive.
But, if you like the super-industrial, high-tech look, it is a material that merits your consideration. One thing for certain, there is little likelihood there will be another kitchen like it in your neighborhood.
The Reactive Metals
For a look that is a little more traditional, some of the old high-reactive or "living" metals are back as upscale countertop materials. These metals, unlike stainless which can stay bright and shiny nearly forever, react with the environment and show all the stains, marks, and tarnish resulting from being in a kitchen environment for years on end.
Copper, which has been a traditional work surface material for centuries is once again available. For a traditional or colonial kitchen, it is an excellent fit. It has a few drawbacks, however.
It is expensive — sometimes more expensive than stainless. It shows every fingerprint, watermark and juice spill, and will tarnish to a greenish-brown color called verdigris unless regularly polished.
On the other hand, those who like things neat and shiny seldom specify a copper countertop. They are happier with stainless.
The inevitable patina that covers a copper countertop is the look most copper owners are looking for. The marks, blemishes, and stains are not just tolerated but sought after.
One great advantage of copper that other metals do not have is that it is naturally anti-microbial.
No one is quite certain how it does it, but copper kills bacteria and fungi on contact, so it is a very hygienic surface for food preparation.
New zinc has a silvery-gray appearance similar to aluminum sheets. It develops a darker blue-gray patina over time as it oxidizes. If you prefer to keep the new look, periodic applications of beeswax will low down oxidation but nothing will stop it entirely. If it gets too dark, it can be polished back to new but it is a lot of work.
Most owners don't bother. The increasingly complex patina of the material as it ages and reacts to its environment is part of the charm of zinc countertops.
It is not a material for those who like things shiny and bright, or for those who are driven crazy by errant water rings and food stains. It will, like copper, show a mark from just about anything that touches it: water, food, fingerprints, juice. But, eventually, all these marks and stains will blend together to form a beautiful dark-gray patina that looks right at home in any heritage kitchen. If you don't want to wait for nature to take its course, treatment with mild acids will bring about that well-used zinc look without the bother or actually using it.
Like copper it is naturally anti-microbial, making it a great surface for food preparation.
Before stainless steel was perfected, zinc was the preferred material for bar tops and restaurant tables because of its longevity and resistance to acids. It was the upscale countertop material of choice through most of the Victorian period and into the first half of the 20th century.
A zinc-top table is almost required in a Victorian kitchen. And, zinc is right at home in any Arts & Crafts reproduction. It requires virtually no care at all other than wiping down.
Most zinc countertops are formed by bending thin sheets of the material over a plywood substrate. The plywood gives the countertop its shape and strength, and the zinc provides its protective finish.
Zinc can, however also be cast to form more formal and elaborate shapes. Casting zinc is a fairly old craft that has been revived in the last 15 years as cast zinc countertops have once again become popular in upscale bars and restaurants.
Both zinc and copper dent fairly easily. One way of reducing the effect is to hammer the material so it is already, in effect, pre-dented. Any additional dents, then are invisible against the hammered surface pattern.
To view how zinc reacts to various foods, beverages and kitchen products, check out this video by Mio Metals.
Glass is one of the traditional materials that you rarely think of when contemplating a new countertop.
Glass Pros, Cons & Ratings
Pros: Water-proof, seamless, non-staining, very sanitary. Cannot be burned, very scratch resistant.
Cons: Costly — about the same as the metals. May not be suited for every style. Can chip or break for which there is no repair except to replace the glass.
Out of 10
Durability - Medium: Immune to household chemicals, stains, and heat. But, it can chip and crack, and there is no possibility of repair. It can only be replaced.
Maintenance - Very Low: Requires no sealing or other periodic maintenance. Cleans with soap and water or Windex®.
Cost - Very High: One of the most expensive materials. Prices start at about $150 sq/ft and go up rapidly.
Green - High: Made of sand, its basic materials make little impact on the environment. We are not likely to run or of sand before the Sun explodes, and it is completely recyclable. Old glass is used to make new glass. But, it does take a lot of electricity or natural gas to make glass.
Glass is one of the materials that you rarely think of when contemplating a new countertop.
It has been used for decades as a covering for tables and desks. But, it is now becoming popular as a countertop surface in both baths and kitchens as fabricators have learned how to make it work in high-hazard environments.
Glass offers an incredible range of design possibilities. It can be cast to create many different shapes, colors, and textures. It can also be combined with other design elements for added effect, such as glass over metal or tile. Lighting under the counter can be used to create visual drama.
Glass is non-porous and extremely sanitary which makes it an excellent countertop and kitchen backsplash choice. It requires very little maintenance and is exceptionally easy to clean.
In the kitchen, it can endure hot pans without cracking or scorching. The thick, usually tempered, glass used to create countertops is exceptionally chip and break resistant.
But if it does chip or crack, the only solution is to replace it. There is no effective repair, so be careful with those cast-iron pots.
Despite the frequent warnings about the sanitation issues of wood countertops for food preparation, serious cooks often prefer butcher block countertops.
But, as it turns out, the danger of wood countertops may have been exaggerated somewhat.
Follow-up studies, such as the one by Deal Oliver at UC, Davis, have found that while bacteria tend to accumulate on both wood and plastic surfaces, wood has natural antimicrobial qualities that help keep bacteria in check, while man-made plastics do not. As a result, wood actually harbors much less live bacterial than most other kitchen countertop materials.
Wood Pros, Cons & Ratings
Pros: "Warmest" of all materials. Most minor damage can be easily repaired. Huge variety of woods, stains and finishes can complement any decor.
Cons: Generally not suitable around water. Can be treated to make it more water resistant but long-term exposure to water will cause damage no matter the treatment. Vulnerable to heat damage, scratches, gouges, and nicks. If improperly installed, expansion cracking may occur. Must be maintained regularly and refinished every few years. Considered by some to be the least sanitary of countertop materials, and some localities do not allow it in commercial kitchens for health reasons but more recent research has shown that the sanitary issues may have been exaggerated.
Out of 10
Durability - Medium: Only as durable as the finish which can be damaged by many household chemicals, can be scratched, cut, and certainly can be burned by hot pans. Any water that penetrates the finish can damage the wood, usually requiring a major repair. Figure on refinishing every few years, a fairly costly process.
Maintenance - High: Requires re-sealing at least monthly and refinishing every few years. Normal maintenance with soap and water but not much water.
Cost - High: A lot of labor is required to build and finish a wood top. Figure about $100 per square foot for standard wood species. Exotic woods can drive the price up rapidly.
Green - Very High: Wood from certified sustainable sources is grown as a crop and managed so as to not harm the environment. Wood is renewable and recyclable, and reasonably green if it is not on the endangered list and not a tropical wood from other than managed forests.
As with other materials, there have been great improvements in the past few years.
For one thing, the variety of woods available is no longer limited to just the traditional rock maple. Mahogany, ash, cherry, oak, mesquite, walnut, beech, and alder are all available as butcher block from a variety of manufacturers, and any one of these can be manufactured locally by a well-equipped cabinet shop.
For kitchen use, any finish on a wood countertop must be food safe. The usual finish is a mineral oil approved for food preparation which is called USP-grade mineral oil. It has to be renewed about every month.
Some wood countertop owners mix beeswax with food-safe mineral oil. Simply shave about 1/2 teaspoon beeswax into a microwave safe dish with a cupful of mineral oil; microwave on high for about 45 seconds. Apply to the countertop while still warm.
Once the finish has had some time to dry it can be buffed to a shine with a dry, soft cloth.
Beeswax helps keep moisture, bacteria, and other contaminants from getting into the wood surface gives the countertop a nice smooth feel to the touch and leaves a subtle, honey-like, fragrance. An alternative to mineral oil is coconut butter.
Modern technology has improved on mineral oil a bit, providing a more durable coating that need be renewed less often, sometimes as little as every three months or so.
Many major coatings (paint) manufacturers sell an oil preparation just for wood cutting surfaces. For example Butcher Block Oil and Finish from Rustoleum. Specialty kitchen suppliers also sell cutting block or butcher block oils. One we like is John Boos' Butcher Block Mystery Oil — a formulation of mineral and linseed oils — so, actually, not much of a mystery.
Dan Meyers of Meyer's Woodworks favors a product called OSMO Polyx-Oil to finish the wood over an epoxy sealer.
Still, no matter what the finish, acids, such as vinegar, and standing water can stain a wood countertop but with re-sanding and re-oiling, the countertop can be renewed over and over, almost indefinitely.
Even More Countertops
We cannot get all of the many varieties of countertop material on one page, so to learn about laminate, engineered composite, solid surfaces, and concrete countertops, continue to the next page.