GuidesStone Care Guides
Natural-Cleft Finished Stone Floors - Slate and Sandstone
Ensure to choose a high-density stone
You got to be very careful while dealing with these types of stones. Slate and sandstone include a wide variety of stones ranging from soft to highly dense. Some of these stones have a higher density and are usually acceptable for floor tiling. Many other types of slates and sandstones are so soft that they merely melt in warm water or crumble under regular foot traffic. Overall, these stones have inherent problems, and you cannot enjoy them for everyday use.
Cultural Difference between New England and Southern Europe
Some of you may argue that people in Southern Europe and many other countries have been successfully using slate for flooring for several generations. Of course, they use the slates to pave their sidewalks too. But you will never find a multicolored slate used for the flooring.
It implies that those people know very well which slate is perfect for flooring and which type of slates they must avoid. They almost always end up choosing the dense category of slates, which in any case is readily available all over the New England region in the form of a dull gray color or at best in green.
Secondly, the most critical factor why southern Europeans use these slates for flooring is that they don't care much about inevitable changes caused by heavy foot traffic. The stone goes through this heavy action to finally reach an everlasting look.
But here, the things are a little different. The vast majority of consumers expect their stones to remain in pristine condition forever. They consider even any natural changes as damage. It boils down to just a matter of culture and has nothing to do with the stone type. However, the crumbling slates and sandstones are exceptions that anyway fall apart.
What should you examine in stone floors?
As a contractor, you need to be highly cautious whenever you visit the customer site to examine stone installations. You have to determine if you should provide your professional services for these stones and if they are worth your time. As a contractor, I have been very selective with slate floors and have never offered my services to work on sandstone floors. I only take the job when the slate seems suitable and involves only the cleaning and sealing work. The cleaning work is not any different from what we do with polished or hone-finished stone floors. However, I found the only difference was approaching various problems differently while cleaning and sealing the slate floors.
The issue of grout chunks
For example, take the case of grout chunks. The natural-cleft finish comes with inherent ripples and roughness with comparatively more grout chunks than a flat polished or honed surface. Besides, it is challenging to remove the grout chunks because scrapers work well only on flat surfaces. Most of the time, you may have to use the blade of a flat screwdriver to remove grout chunks from stone pits. When you can use your three-inch razor blade scraper, you must be extremely careful not to scratch the stone.
Weird light stains and scratches
The next problem that you need to deal with is the strange light stains and scratches. Several slate types are equally sensitive to acid spills like marble floors are and sometimes even more than that. They are responsible for these weird-looking light stains, also known as etch marks. Sometimes, even a mildly acidic glue of some adhesive tapes can also etch the slate floors, whereas most marble floors remain unaffected.
Can you fix the altered finish of the original stone?
You already know how to repair etch marks or scratches from flat surfaces, but you may not have any idea about how to deal with this problem on a rippled surface. You may try using a variable speed right angled grinder or polisher with a seven-inch dia brush with a good quality honing powder to spot-hone the etch marks. Even if you successfully remove the etch marks, you will usually end up in a situation with a changed finish of the original stone. What about the scratches. Probably, you can't repair them.
What is the solution, then?
You will have to arm yourself with a good quality stone color enhancer. After etching and scratches, the damaged area starts to look light-colored. A good quality stone color enhancer can enhance the original color to blend permanently into the surroundings to make it uniform and vibrant. That is the perfect way to make the scratches and etch marks disappear and blend into the backgrounds. There is one more plus point attached to a good quality stone color enhancer. It also works as an impregnating sealer. It implies that you will be able to kill two birds with one stone.
The process summary
To conclude, the overall process goes like this. First of all, you will complete the floor detailing. Then you will scrub the floor with a machine by using the attached cleaners, as mentioned earlier. Let the floor dry by leaving it for an appropriate time. Finally, you will complete your job by applying a good quality stone color enhancer cum impregnating sealer. It will take care of all the etch marks and scratches by blending the color and impregnating the floor effectively.
What if your client insists on topical coating?
If the client insists that you should seal the slate floor with a urethane-based topical coating, you will have to drop the idea of using a stone color enhancer/ impregnating sealer. If you use the color enhancer, it will prevent the topical sealer from adhering to the stone surface correctly, thereby leaving scope for potential future damages to the slate flooring and other associated problems.
While applying a urethane-based topical coating, please ensure keeping the urethane wet enough to work just like your color enhancer works during the coating process. As a professional, I suggest that you should use the latest generation of water-carried urethane, which is the best coating in my opinion.