Why Do Stone Problems Occur?
Originally Presented in 1992
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.
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.
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 Harry’s red. 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 Harry’s red 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, especially New York, 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 Tim’s red, since it was cheaper and close in color to Harry’s red.
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.
K N O W L E D G E:
All parties entering into an agreement to supply or use stone must be knowledgeable of what they are doing, buying, and using. We should require the following:
1) Proper naming of stone
2) Proper testing of stone to make sure it is sufficient to pass the ASTM tests required for its use.
3) Knowledge of the recommended application for the stone and indications where it has been used before successfully.
4) Knowledge of the quarry to better understand whether it is only one quarry handling this material or many. If so, how do we select the right quarry for the selection we are making. How does the stone change in testing from inside various areas of the quarry to other quarries?
5) The stone color variation. How many samples of 12 x 12 are needed to understand this stone. Why not supply pictures of slabs and the quarry to show this as well?
6) How does the rift in the quarry affect the stone? How do we specify the quarry name and location within the quarry? Is the stone cut with the bed or against?
7) Can we specify or offer blended material from contiguous blocks? 8) What thickness will we recommend? We must be knowledgeable of all applications the architect/designer intend to use the stone.
9) Is the stone available in the quantity needed for this job in a timely fashion? This is always a problem.
10) What finish are we going to recommend? The architect wants polish but we know it is for floors and the MIA does not recommend polish for floors. What shall we do? Give the architect what he wants, I guess?
11) Can we suggest budgets for this job in advance to know whether it is even affordable by the owner and General Contractor for this job? We should all ask for preliminary details about the job to know more and check them out in advance.
12) Give installation recommendations for each area of the job.
13) Most importantly, know the stone well enough to recommend at time of specifications maintenance procedures.
14) More information on the supplier from whom the stone will be bought. I have another pass out on a typical form you may use to require more information about the supplier. It may help you identify the strengths and weaknesses; and better understand the capability of the supplier.
15) More information about the stone. Trade International, Inc. is developing a program dealing with stone identification. There is another pass out showing you a typical outline of what we will try and procure about stone. This should be a guideline for you and for the end user to require from all parties about the stone. The more you know about the stone the better. If you can not acquire substantial information about the stone, do not use it.
C O N T R O L:
We all need control on this job if it is to be successful. Control starts by the distributor supplier, is supposed to be enforced by the architect/designer, and then is to be adhered to by the General Contractor and stone supplier. Who establishes and implements these controls?
We all do. It is the job of everyone to know better the stone and the controls required to give the owner what he expects. Some things that should occur are as follows:
1) Proper samples to show color range in the beginning and extra sets of these maintained by the suppliers to control it during production.
2) Better specifications to support the suppliers who have helped you set up these controls and who have proven they can control the stone.
3) Proper testing of stone before and during the job.
4) Knowledgeable stone contractors who know the problems with the specific stone in question and the installation method that must be made to assure quality and problem free maintenance.
5) Purchase orders that state clearly the stone name, date required, quantity, MIA specifications for quality control, ASTM testing requirements and performances, color control per samples, price, labor items and tolerances , shipping and packing instructions, penalties for late delivery-improper fabrication-or variance of the details specified. You would be amazed at how many purchase orders I see that say nothing more then ship 25,000 SF of White Carrara 12 x 12 x 3/8 tiles polished. What does this mean? How much control are we going to have? What is white Carrara?
6) Controls on shipping and expediting to the job; assistance on unloading and storage at the job; instructions on storage and movement to the work area and how to protect the stone from other trades walking over the new stone area just installed.
7) Careful watch on the installation being used; how the stone is sorted and selectively installed at the job; the grouting and cleaning of the finished worked area prior to signing it off to the owner.
8) Maintenance brochure or instructions on how to take care of this beautiful job and what to look out for and what to do when you have a problem.
9) One of the most important controls is to not always give the job to the cheapest bidder. We need to change this method in the USA. We need to award jobs to the most competent, the most informative, the most supportive. Usually there are enough of these people to supply us with competitive bids.
10) And finally we need to control alternates. If the architect/designer has not done his/her homework before the bid date to allow alternates, then none should be allowed. The architect must control the general contractor and what they are allowed to do in order to control this job and the design originally intended.
To give you an example, the Coca Cola building in Atlanta has a beautiful atrium with a design patterned floor. It was recommended to them not to use Negro Marquina. And further, if they did use it, to test and select a proper sealer to protect it. They used Negro Marquina and the job was specified to have a sealer. No sealer was used. The open house came and they served Coke and Champagne. What a combination. Of course, we all know what happened. The floor lost its shine quickly. The next day the architect was on the phone to find out what he was to do, knowing full well what he already knew and should have done.
The stone industry requires all parties to be knowledgeable and exercise control. If the industry is to have progress then we must be more aware of what we are doing.
With the advent of 10 new countries getting into and supplying stone into the market it becomes more important to set buying and specifying guidelines. We now have two well known Spanish materials, Rosa Porrinho and Negro Marquina available from China. Any country can buy the technology and machinery required to produce dimension stone, even though they may not have the background in making it or supplying it in the world market.
It is up to all of us to take better care with these new suppliers and pass on our knowledge to them of the needs of the market and the quality control and education that is required. It is a shame to have failures occur over and over again for the same reason. It shows lack of unity and lack of control.
We are supposed to be one of the most highly advanced nations of the world, yet we are lacking in controlling our own business for which we all make a living.
Man is supposed to be a creature with a brain who studies history and learns from our past mistakes in order to make the future better for our children. Why not carry this philosophy into the stone business and work together to make it a better industry. We will all benefit.
Let’s not treat natural stone like manmade ceramic. Let’s appreciate the natural beauty of this product, learn to control it in our favor, use it wisely, and have it last for years to come. With knowledge and control we can do this.