FAQ

Here are some of the questions most frequently asked by our clients, followed by our opinions on each topic. If you have any other questions, just ask. We love to discuss stone!

Why do you recommend certain limestones for kitchen floors and bathrooms?

In choosing a stone it is important to consider how the stone will change over time. Many of the more porous stones will stain easily and unfortunately, even the best impregnators may not be good enough. If this aged look is what your client wants, then any limestone will do.

If your client is a bit more particular, we suggest you consider what the French call "Pierre Marbriere" or in English, "Marble Stone". A "Marble Stone" is a metamorphosed limestone that has become considerably denser and harder while in the Earth's crust. Limestone such as Villebois Jaune, Saint Baudille, Demi Roche Gris and Saint Croix are a few. Ask us for samples. You will find these stones are more stain and wear resistant. Unfortunately, as carbonates, "Marble Stones" are acid sensitive.

Why are certain stones more practical as kitchen counters than others?

We must answer this question more often than any other. The answer lies in the true and purest difference between the basic stone groups we sell. If we can impart an understanding of these differences we can increase the chance that the end user will be happy with the stone selected - and more than anything else, that's the key to our success.

The two most important words we need to remember are "carbonate" and "silicate". Simply stated, the important difference is that a carbonate is acid sensitive and a silicate is not. A silicate, like granite, for example, does not react to acid. If we take a lemon (citric acid), something found regularly in our kitchens, and squeeze the juice onto the stone, nothing happens. If we take the same lemon and squeeze the juice onto a carbonate, such as marble, the stone starts to dissolve immediately. Like Tums, also a calcium carbonate, the stone neutralizes the acid quickly so the damage is not deep. Unfortunately though, the damage will be the loss of the smooth finished surface. Acids will do more damage to a polished stone than a honed or matte finish. Both etch equally, but it's just more noticeable on polished stones. Try this test yourself. A little experimentation works wonders - but do not use your cocktail table. Remember one of the great things about stone is that we can usually restore the stone to its original beauty.

What stones do you recommend for kitchen countertops?

We know the stones, but we do not know your clients. As you well know, each client's tolerances are different. Some love the aged look of a Carrara kitchen and others... we'll just call them granite people.

From our last topic, we know marble and limestone will etch. Darker stones etch more noticeably. Some will also be more apt to stain, but we can impregnate the stone to improve performance - the denser stones will still be better. The bottom line is, as much as we love marble and limestone kitchen counters, these surfaces are not for everybody.

Many green marbles make good kitchen counters - mainly because they are not true marbles. These wonderful greens are natural stone, but not calcium or magnesium carbonate, as in marble, but rather magnesium silicate (serpentine). Our industry takes artistic license here, and deviates from the science of geology by labeling greens as marble because of their marble-like appearance. Pure serpentine is not acid sensitive, therefore there is no etching. Be careful here - not all greens are pure serpentine. Some lighter greens, like Spring Green, have some carbonate mixed in, and will react to acid. Also, there are greens that are true marbles such as Verde Antigua and Cippolino, so be sure to ask us first.

What other stones do you suggest for use as kitchen counters?

Here are some of our favorites: Pietra Cardosa. We think this stone is schist or greywake. We are not sure, and we have started a few battles among geologists trying to answer the question. The important point here is that the stone is mostly silicate with great abrasive resistance.

Burlington Stone. Broughton Moor, Elterwater, Bursting Stone, or Brandy Craig are the quarry names of volcanic silicates from the Lake District of England. These stones contain a small percentage of carbonate, significantly less than a limestone. Our experience tells us that these stones make excellent counters, and react adversely only when acid solutions remain on the surface for an extended period.

Galaxy and Crow's Foot Schist. Both are quarried in New England. These stones we know as schist. Both are silicates and are very "counter worthy". Come see them both in our showroom. They alone are worth the trip!

Why does my granite stain?

Remember, many are porous, especially the popular swirl varieties. These swirl types are often not even true granites (more artistic license). Geologists use the term gneiss. Gneiss is usually made of the same material components as granite, only the stone cools more quickly in the earth's crust. Their swirls still show the movement of the stones active molten history. The important part is that these stones, with smaller crystals, are more porous than granites with large crystals. Impregnators are needed to reduce staining.

Can I get the stains out of my stone?

We rarely meet a stain we can't get out. While this may be an exaggeration, we have a pretty good track record. Removing a stain is a three-part process, the first stage involves identifying the stain, the second stage involves loosening or dissolving the stain, the third stage involves lifting the stain from the stone.

We don't suggest you get too sophisticated if you are doing this yourself. But before calling for help, try a simple colorless dish washing detergent or our "Deep Stone Cleaner" to loosen many grease or oil stains that then can be removed by blotting with a paper towel. If this fails, K2R will often be effective. K2R is a poultice in a can, a solvent (carbon tetrachloride) that dissolves the stain and a powder to absorb and lift the stain. If these things fail, it is often best to call a stone maintenance professional. The professionals will know the tricks to dissolve the tough stains and they will avoid the chemicals that may damage the stone. If you are interested, there is a great book written by Fred Houston "Stain Removal Guide for Stone".

Do you recommend polished floors in commercial spaces?

There are two considerations when specifying polished stone on commercial floors - slip resistance and wearing off the polish. Regarding slip resistance, polished floors generally do not pass industry standards testing for slip resistance, unless treated with certain floor finishes made for that purpose. The full answer to this question is lengthy. If you call us, we will be happy to go into the full explanation. Regarding wear, all polished stones will lose their polish unless there is a constant maintenance program including the use of chemical finishes that will protect the finish. This can be expensive over time, and require stripping and reapplication from time to time. In our opinion, if the owner wants a polished finish floor, it is important that you discuss the maintenance requirements before specifying.

Is slate a tripping hazard?

In our opinion, no. As the area's largest supplier of imported slate, we have sold lots of slate, and have never had any complaints that people were tripping on the cleft areas of properly installed slate. We have had some specifiers concerned about it, and have decided not to use slate, but those who went with it, were always happy, to our knowledge. One consideration is that there are usually some pieces within a slate shipment that the tile contractor should sort and not install. We always recommend that this instruction be indicated in the project's stone specifications.

How can I be sure that the color and veining characteristics of the stone I specify will be what I want?

That depends on a number of factors. The best way would be to go to the supplier's warehouse and inspect as much material as you need to make you feel comfortable. If the stone is coming from the factory, you may need to go there to see the look of the stone before it ships or is processed. We suggest that what is most important is that you have a supplier who you can trust, and who is willing and able to communicate the stone's variation. Always view full size tiles, and not specify a stone purely from a small chip. Sometimes it is important that the factory send "range" samples, which can be used to communicate the potential color range. In general, we believe that it is important for designers and architects to understand that stone, as a natural material, is beautiful because of its variation, and that trying to control mother nature can be difficult, and sometimes, impossible.

Can I specify that there be no grout joints between tiles?

We believe that you should not. In order to be able to install stone tiles without a grout joint, three perfect conditions must exist: a perfectly flat floor, a perfectly square tile and a perfect installer. Since all three, for all intents and purposes, are rarely perfect, you cannot get a floor without grout joints. However, in a perfect world; in other words, a project without a budget, you can have all three, but be prepared to spend lots of additional money.

What are the tightest grout joint widths I should specify for natural stone tiles?

That will usually depend on the tile. Marble, granite and limestone tiles are usually cut from blocks and then turned into tiles on a tile saw. If produced by a good tile factory, these tiles will have a size variance that will allow for a 1/16" grout joint. Imported slate, and other stones, such as quartzite and sandstone, are usually produced with a size variation that will only allow joints from 1/8" to 3/8", depending on the stone and factory. Always check with the supplier before specifying the joint width on these stones.

How do I make sure that the stone I specify will be available when my project needs it?

If you know when the stone is required, you should communicate this to the stone supplier. A trustworthy supplier will give you reliable information regarding the stone's availability. If this is a fast track job, and the material is in stock, some suppliers (such as us) will put the material on hold for a week or two until a final commitment is made. Communication between the specifier and the general contractor or owner is often important in order to meet job delivery requirements. If material needs to come from overseas, we generally assume that it will take around a month to get to our warehouse. If it takes the factory one to two months to produce the stone to specifications, then a lead-time of two to three months would be common. This is a typical availability situation, but will not be the case in all situations.

What is the typical cost of stone?

There is no real good answer to this question, which we are often asked. The best answer we can come up with is based on prices for 12"x12" tiles we give to contractors. The least expensive natural stone is imported slate, which we sell for from $3 to $6 per square foot. Limestone and marble will both vary in price from around $5 to $12, depending on the stone. Granite will usually range from $7 to $14 per square foot. These prices are based on cleft finishes in slate and polished or honed finish in the other stones. Flamed and other finishes will usually raise the price $1 to $2 a square foot.

How does an impregnator reduce the staining prospects of natural stone?

The solid part of silicone impregnators are microscopic balls of silicone that attach themselves to the crevices inside the stone. These balls of silicone are negatively charged, which means they repel each other so that they cannot combine in one big ball of silicone. Once they are attached to the stone, these balls become a permanent part of the stone, and give out a magnetic charge, which creates an invisible "umbrella" between the balls. These microscopic umbrellas act as shields when a much larger drop of liquid lands on them. They hold the liquid up, and prevent it from penetrating the stone.

The liquid part of the impregnator, is usually either mineral or water based, and acts as the carrier that brings the silicone to the stone and has it penetrate deep into the stone. The most effective impregnators use mineral spirits and have the smallest particles of silicone.