Having worked within the industry for longer than I would like to admit, I have answered the most diverse questions from many different parties, including architects, interior designers, contractors, kitchen manufacturers and home owners.
There are a few common misconceptions that I hear on a regular basis and I would like to address the top 5 here, in the hope that this will help you make a more informed decision when selecting natural stone for your next project.
1. Granite worktops DO require sealing
I am often asked whether granite requires sealing (i.e. the application of a surface treatment to natural stone materials to retard against staining and corrosion). The answer is yes. Granite – like all natural stone – requires sealing.
I suspect that the confusion comes from the fact that quartz does not require sealing and with granite being as strong as quartz… well, you do the math. When we talk about ‘quartz’, we tend to refer to man-made quartz, also known as quartz-based composite, or simply quartz. This consists of powders of quartz – and typically other natural materials – all bonded together with resin. Man-made quartz does not require sealing, as they are manufactured with the intentional purpose to improve performance by enhancing natural stone’s properties and limiting its flaws, including the porosity of the capillarity channels that permit penetration of liquids and gases.
So, to answer the question, granite is a natural material and requires sealing.
2. All limestone is NOT the same
Geologically, all limestone is sedimentary rock. However each and every limestone forms in a determinate time, under certain circumstances and with specific water and climate conditions. The combination of these factors determines its characteristics, including hardness.
For example, Tuffeau limestone from the Loire valley in France is a very soft limestone that is most often used as a building stone, but is too soft for flooring. On the other hand, from Northern France comes Chambord, a very durable and hard-wearing limestone with excellent characteristics, including anti-slip and frost resistance, that make it suitable for all uses, both internally and externally. So much so that I tend to use it as a more cost-effective alternative to Portland stone. Our range of limestone is very wide and you will find many that are suitable for your project. I can’t stress enough how important it is to understand the characteristics of the stone so that we can choose one that will perform adequately.
3. You CAN use marble as kitchen worktop
Granite and quartzite are generally harder than most marble. That’s why granite took over as the popular stone of choice for kitchen worktops and counter tops. However, this doesn’t mean that – for the right project, with the right clients – you can’t use marble. Yes, you heard me!
First of all, as we said in Point 1 above, each stone is unique, geologically speaking. Some limestone is very hard. Think of Wellington limestone, whose properties are very similar to those of marble.
Secondly, not all home owners are the same. If you and your clients are aware of what having a marble kitchen top entails and are prepared to look after it (and it is common sense here, not rocket science), then I say “go for it”.
I would probably recommend a honed finish, because acid liquids such as vinegar and lemon juice, will take the polish off, if spilled and left on the surface for long enough. On the other hand, the sealers that are now available on the market are so good that honed finishes are just as protected from stains as polished ones.
Whilst it is easier to keep granite in good conditions, as opposed to marble and limestone, every natural material will eventually look “lived in” after a long period of use (don’t forget what we said earlier about sealants: they only retard against staining and corrosion).
Personally, I am seeing more and more architects, designers and home owners opting for marble for their kitchen and counter tops.
4. It is NOT OK to tile onto moisture resistant plasterboard
We hear this frequently when discussing the substrate for tiling bathrooms, wet rooms and shower enclosures. It is often wrongly assumed that the green plasterboard is the correct product to use in bathrooms.
Moisture resistant plasterboard or “green” board is not actually waterproof or even water resistant. The plasterboard will deform and swell when it gets wet and this will result in tiles debonding and falling off the wall.
Using plasterboard in bathrooms is one of the most common causes of failure that we hear about, whether you use porcelain or ceramic tiles, as well as natural stone. Finally, a paper-faced board cannot take the weight of the average marble or limestone tile.
5. Limestone is NOT too soft to be used in bathrooms
Certainly, some limestone is softer and more porous than others, making it problematic to seal adequately in a wet area. Therefore, it is recommended to choose a stone that is better suited for such environment. But that doesn’t mean that you cannot or should not use limestone in a bathroom.
There are many types of limestone that are dense, so much so that they could be mistaken for marble. Crema Marfil is one such example and there are plenty of others.
Marble is a metamorphic limestone that has lost the fossils and other features during the recrystallization process at extremely high pressures and temperatures below melting. As this process is gradual, there are plenty of limestone materials that are halfway through this process. This means that they are geologically limestone, but they offer improved physico-mechanical properties and marble-like looks. Examples are Medi Black, Marron Mirabelle and Breccia Elisea, just to mention a few.
For some extra tips for routine care and cleaning of natural stone floors and surfaces, read our blog “DOs and DON”Ts of natural stone maintenance”.
If you are thinking of using natural stone in your project and want to know what’s fact and what’s fiction, speak to us.
We are always happy to provide more in-depth information, explain how we can work together and how we can help make your next project is successful.