Why Do Stone Problems Occur?
STONE SELECTION
Many times it is because the stone is not selected correctly for the use it is intended. The stone then fails because of cracks, holes, staining, improper thickness, improper blending or understanding of the stones range in color, improper size, lack of suitability for exteriors, or the lack of abrasive resistance required for such a floor, or the high absorption of the stone.
INSTALLATION
Perhaps the problem occurs due to improper installation. It should not have been made so thin; or it should have been set with white cement instead of grey; or epoxy rather then portland cement; or the anchorage system was not sufficient; or weep holes were not allowed; or oil based products stained the stone. There are a hundred reasons why stone installations fail.
MAINTENANCE
Finishing and maintaining stone is just as important as all the above. If the stone was polished and showing wear, you will have problems. If the stone is highly absorptive and a sealer should have been used and wasn't, then a failure will occur. Perhaps the foot traffic is too heavy for the area and it might have helped to have a sealer. Or perhaps the stone is in a wet area where water and rust penetrates the stone. Sometimes the sun will discolor the stone, or oxidation occurs due to metallic content in the stone.
Many times stones are fractured and have open seams. The stone is set with colored epoxy grout which gets into the seams and Voila, a problem occurs.
Who is at fault? What should have been done? What can we all do?
Education is most important. There are very few stone experts and fewer still, salesman who know stone. Architects demand knowledgeable stone people to call on them and assist them to avoid all the above problems. Perhaps the stone they require for the job must withstand high traffic on pavers, or high tensile strength, or better density and absorption, or flexural strength.
HOW STONE IS TYPICALLY SPECIFIED
Let me outline typically what happens in buying or specifying stone.
The architect/designer has a job. They find in their local area a distributor who demonstrates some knowledge of stone. So they request a salesman visit them. This salesman comes in with all sorts of granites, marbles, slates, limestones etc.
The architect/designer are impressed with the available selections open to them. Perhaps the salesman did not visit them and they just saw it on another building, or they had a catalog and sample kit sent to them. Whatever method was used, they narrowed down their selections to stones pleasing to the eye in color that superficially suited their needs. The supplier/distributor was advised about the selection (sometimes not) and samples were requested.
Wow, they received 6" square samples and if they were really lucky a whole 12 x 12 sample. The name of the stone was Cremo Anatolia. What a nice name. The architect/designer asked for testing and information, for which of course either none was available, or that which was supplied was 5 years old and not from the quarry for which the sample came.
We want polished marble tiles on the floor says the architect. OK, no problem says the supplier, we make it 12 x 12 x 3/8 inch. Seven months later the job comes out for bid. The specs read Cremo Anatolia by XYZ supplier in 12 x 12 x 3/8" polished tiles. The contractors get the drawings and find they need 25,000 Square feet. They have 1 week to bid the job, three days only after the take off is done.
The contractors start calling around to locate the stone and perhaps they call the XYZ supplier specified. When XYZ supplier gets the call he says, OH really, I did not know it was out for bid, how much stone is involved and when do you want the bid? Tomorrow answers the contractor as he goes and calls all his other friends and suppliers domestic or foreign to locate a cheaper source.
The contractor gives a price and or alternate. What does it mean specified stone? Most General Contractors, state we do not give out specified suppliers names and we always allow alternates.
The cheapest supplier/contractor/general contractor etc. is awarded the job. The job is installed with another one, since it was cheaper and close in color to Cremo Anatolia.
Now what is wrong with this scenario? Anyone know? This has happened to hundreds of people everyday throughout the world. Stone problems occur. We are all at fault for various reasons. We need to change our way of buying, selling, bidding, and controlling stone.
The two key words I will give you today, and I hope you take these home with you, is KNOWLEDGE AND CONTROL.