Thursday, July 16, 2020

Is Your Stone Business Taking your Breath Away?

Is Your Stone Business Taking your Breath Away?

 

Frederick M. Hueston, Technical editor 

Does your shop cut, grind or hone stone dry. If so, you may want to pay attention to this article.  Dust created from cutting and grinding certain types of stone will emit silica in the air. If you or your workers are not using the proper respiratory protection, you could be exposing yourself and your workers to serious health problems. Breathing silica dust can cause a disease known as  Siliceous.  More than 250 people each year die from this disease and over one million workers in the US are exposed to silica dust. The really bad news is that there is no cure for it. The good news is, it is very preventable.* The way to prevent silicosis is simple...cut, grind and polish all your stone wet and you wont have to worry about it.

What stone types contain silica?

All granite as well as certain slate and some marbles may contain harmful silica dust.  I would make the assumption that all granites and slates contain silica.   Most marble except for a few green varieties have silica.  Limestone generally will not contain silica, although there are a few which may. All quartzite’s and stone containing quartz will have silica.

The following article was taken from the Washington State Department of Labor and Industry(www.lni.wa.gov/wisha/hazalerts/hazmay98.htm). Most states will have there own exposure limits and I would encourage you to check with your state Department of Labor. OSHA also has a federal limit which you should be aware of. OSHA also has some excellent info on siliceous and protecting yourself on their web site at www.osha‑slc.gov/SLTC/silicacrystalline.

 

 

 

*www.osha‑slc.gov/SLTC/silicacrystalline/


Designing a Sustainable (Green) Stone Floor Maintenance Program

Designing a Sustainable (Green) Stone Floor Maintenance Program

By Frederick M. Hueston

 Walk into any stone, terrazzo or janitorial chemical supplier and you will find an endless selection of cleaners, sealers, restorers, etc to keep you terrazzo and stone floors looking new.  The problem is many of these chemicals can be harmful to the user, occupants and the environment.  How does one design a program that is not only sustainable and safe but to also keep your terrazzo and stone flooring in like new condition?

Fortunately there is an effective way to not only maintain these surfaces but also to keep them looking new. The following guideline will show you how to develop a sustainable maintenance program. This is especially important for schools, hospitals and other buildings were children and people sensitive to these harmful chemicals are present everyday.

 he dangers of floor strippers, finishes etc have been studied by many organizations including universities, etc. Here is a partial list of those studies

 

- Green Seal Report

Floor Care Products: Finishes and Strippers

www.greenseal.org/resources/reports/CGR_floorcare.pdf

 

-Safe and Effective Use of Floor Finish Strippers

Janitorial Products. Pollution Prevention Project

Sponsored by US EPA

www.wrppn.org/janitorial/factsheet/floor.htm

 

-Health Hazard Evaluation Report 95-0313-2589, University of Michigan Hospitals, Ann Arbor, Michigan

 

-NIOSH [1990]. NIOSH criteria for a

recommended standard: occupational exposure to

ethylene glycol monobutyl ether and ethylene

glycol monobutyl ether acetate. Cincinnati, OH:

U.S. Department of Health and Human Services,

Public Health Service, Centers for Disease

Control, National Institute for Occupational

Safety and Health, DHHS (NIOSH) Publication

No. 90–118.

 

-Ruth JH [1986]. Odor thresholds and irritation

levels of several chemical substances: a review.

Am Ind Hyg Assoc J 47:A142–A151.

WHO [1983]. Indoor air pollutants: exposure

and health effects. World Health Organization

Regional Office for Europe. WHO–EURO report

and studies no. 78, Copenhagen, Denmark.

 Program Guidelines

 step 1.  A good sustainable maintenance program starts with proper identification of the stone.  Is it granite, marble, terrazzo or limestone?  If it’s marble is it soft or hard?  What type of finish does it have? Polished, honed, flamed, etc.? Is the type of stone the proper material for the traffic it is to receive?  If not maintenance costs will be higher.  If the answer to these questions are unknown, I suggest you contact a reputable stone supplier or restoration company to find out.  A complete understanding of your particular stones characteristics is an absolute must for designing a sustainable maintenance program.

 Step 2.  Once the stone’s characteristics are identified determine the quality of the installation.  Are the tiles flat and even?  Do they contain lippage (uneven tiles).  If so, proper maintenance may prove difficult.  The floor should be ground flat, honed and polished using sustainable restoration procedures that utilize non-chemical methods.  Are there any cracked tiles?  Dirt will have a tendency to accumulate in these cracks.  These tiles should be replaced or if replacements are not available at least repaired.

 Step 3.  What is the present condition of the stone?  Has it been coated with waxes, acrylics, urethane or other coatings?  If so these coatings need to be ground off to determine the condition of the stone as well as eliminate any toxic and unsafe properties.  I have seen stone floors that appear to be in great shape until the coatings are removed to unveil a pitted, scratched mess.  If a poor condition is found, complete restoration is necessary before a successful sustainable maintenance program can begin.

 Step 4.  Once the stone is restored to like new condition, then and only then will a sustainable maintenance program provide good results.  This applies not only to the following program but any program.  If the stone will be exposed to water, coffee, spills etc, an application  of a an approved Green  impregnator is recommended.  These impregnators are designed to penetrate into the stone,  without leaving coatings on the surface and still allowing the stone to transpire(breathe). They contain no harmful vapors or off gases when cured.

  Step 5.  Daily Maintenance

 The three most important tasks that can be done on a daily basis to keep the stone looking new and extending the time before restoration is required are: Dust Mop, Dust Mop and Dust Mop.  The most destructive material to most stone is sand, dirt and miscellaneous grit.  If these substances could be eliminated, maintenance of the stone would be almost non-existent.  A stone floor can never be dust mopped too often.  Use a clean, non-treated, dry dust mop at least two to three times a day in high traffic areas and less often in low traffic areas.  Walk off mats placed outside and inside an entrance will also eliminate a good portion of sand, dirt and grit.  It takes approximately seven steps to remove all loose dirt from the bottom of ones shoes. Walk off mats also need to be removed and cleaned daily. Keep this in mind when purchasing walk off mats.  Remember if sand, dirt and grit are eliminated there will be nothing left behind to scratch and dull the stone.

 Note: Coatings in addition to potentially being hazardous contribute to accelerate wearing of the stone or terrazzo surface by acting as a magnet for dirt and debri. It has been shown in studies that a stone or terrazzo floor without any coating will be easier to maintain as well as more cost effective.

                                                   

Step 6.  Cleaning

 All natural stone, both polished and unpolished should be cleaned daily in high traffic areas and less often in lower traffic areas.  A clean rayon or cotton string mop should be used with cold to warm water with the addition of a quality Green Approved neutral cleaner or stone soap. Approved Green Neutral cleaners are defined as surfactant type detergents that have a Ph of 7.  Acidic and alkaline cleaners should not be used.  Be sure to follow the directions very carefully. 

 

 Why Does Stone Shine?

 

All stone is taken from the earth in a raw block form.  This block is cut into slices that we call slabs.  The slabs are then cut further to a smaller size such as a tile or countertop.  It is then polished using a series of abrasive materials.  The mechanics are relatively simple.  A piece of stone is rubbed with a series of abrasives starting with a course grit size followed by

Finer and finer grit sizes.  The scratch pattern left behind from one grit is removed by the next grit creating finer and finer scratches.  This process is continued until the scratch pattern becomes microscopic.  The process is similar to refinishing a piece of wood, starting with a course sandpaper and ending with a fine sandpaper.  The shine is placed on the stone by continuing this abrading process using very fine powders. With sustainable(Green) restoration methods no chemicals are used.

  

Restoration

Periodically the stone will need to be restored.  Perhaps you have not followed a proper maintenance program or the type of stone you have is not suited to the conditions it receives or for what ever other reason it is not responding to maintenance, then restoration is required.  How often this will need to be done is difficult to determine.  Generally if all the precautions above are followed, restoration may only be needed as often as once per year or as little as once every five years or so.  The restoration process re-hones the stone to remove deep scratches and is then re-polished.  Do not attempt the re-honing process yourself, this requires a great degree of skill and experience, please call a reputable restoration company who specializes in sustainable methods for this task.

 

Natural stone was the first building material used by man.  Its care and maintenance is one of the oldest tasks performed by our ancestors and was maintained without any of today’s modern chemical products.  The above guidelines were developed by our years of experience with this beautiful material and with the addition of sustainable practices will provide many years of beauty.

 

 

Written by

 

Frederick M. Hueston,

Stone Forensics

E-Mail: Fhueston@stoneforensics.com

Web Site: www.stoneforensics.com

 


Designing a Stone Floor Maintenance Program

 Designing a Stone Floor Maintenance Program

 

Program Guidelines

 

Step 1.  A good maintenance program starts with proper identification of the stone.  Is it granite, marble, quartzite or limestone?  If it’s marble is it soft or hard?  What type of finish does it have? Polished, honed, flamed, etc.? Is the type of stone the proper material for the traffic it is to receive?  If not maintenance costs will be higher.  If the answer to these questions are unknown, I suggest you contact a reputable stone supplier or restoration company to find out.  A complete understanding of your particular stones characteristics is an absolute must for designing a maintenance program.

 

Step 2.  Once the stone’s characteristics are identified determine the quality of the installation.  Are the tiles flat and even?  Do they contain lippage (uneven tiles).  If so, proper maintenance may prove difficult.  The floor should be ground flat, honed and polished.  Are there any cracked tiles?  Dirt will have a tendency to accumulate in these cracks.  These tiles should be replaced or if replacements are not available at least filled with a polyester.

 

Step 3.  What is the present condition of the stone?  Has it been coated with waxes, acrylics, urethane or other coatings?  If so these coatings need to be chemically stripped or ground off to determine the condition of the stone.  I have seen stone floors that appear to be in great shape until the coatings are removed to unveil a pitted, scratched mess.  If a poor condition is found, complete restoration is necessary before a successful maintenance program can begin.

 

Step 4.  Once the stone is restored to like new condition, then and only then will a maintenance program provide good results.  This applies not only to the following program but any program.  If the stone will be exposed to water, coffee, spills etc, an application  of a good quality silicone based

 impregnator is recommended.  These impregnators are designed to penetrate into the stone,  without leaving coatings on the surface and still allowing the stone to transpire(breathe).

 

 

 Step 5.  Daily Maintenance

 

The three most important tasks that can be done on a daily basis to keep the stone looking new and extending the time before restoration is required are: Dust Mop, Dust Mop and Dust Mop.  The most destructive material to most stone is sand, dirt and miscellaneous grit.  If these substances could be eliminated, maintenance of the stone would be almost non-existent.  A stone floor can never be dust mopped too often.  Use a clean, non-treated, dry  dust mop at least two to three times a day in high traffic areas and less often in low traffic areas.  Walk off mats placed outside and inside an entrance will also eliminate a good portion of sand, dirt and grit.  It takes approximately seven steps to remove all loose dirt from the bottom of ones shoes. Walk off mats also need to be removed and cleaned daily. Keep this in mind when purchasing walk off mats.  Remember if sand, dirt and grit are eliminated there will be nothing left behind to scratch and dull the stone.

 

                                                      

Step 6.  Cleaning

 

All natural stone, both polished and unpolished should be cleaned daily in high traffic areas and less often in lower traffic areas.  A clean rayon or cotton string mop should be used with cold to warm water with the addition of a quality neutral cleaner or stone soap.  Neutral cleaners are defined as surfactant type detergents that have a Ph of 7.  Acidic and alkaline cleaners should not be used on a regular basis.  Be sure to follow the directions very carefully.  Too much cleaner may leave a film and cause streaking.

  

 

Why Does Stone Shine?

 

All stone is taken from the earth in a raw block form.  This block is cut into slices that we call slabs.  The slabs are then cut further to a smaller size such as a tile or countertop.  It is then polished using a series of abrasive materials.  The mechanics are relatively

simple.  A piece of stone is rubbed with a series of abrasives starting with a course grit size followed by

finer and finer grit sizes.  The scratch pattern left behind from one grit is removed by the next grit

creating finer and finer scratches.  This process is continued until the scratch pattern becomes

microscopic.  The process is similar to refinishing a piece of wood, starting with a course sandpaper and ending with a fine sandpaper.  The shine is placed on the stone by continuing this abrading process using very fine powders.

 Restoration

Periodically the stone will need to be restored.  Perhaps you have not followed a proper maintenance program or the type of stone you have is not suited to the conditions it receives or for what ever other reason it is not responding to maintenance, then restoration is required.  How often this will need to be done is difficult to determine.  Generally if all the precautions above are followed, restoration may only be needed as often as once per year or as little as once every five years or so.  The restoration process re-hones the stone to remove deep scratches and is then re-polished.  Do not attempt the re-honing process yourself, this requires a great degree of skill and experience, please call a reputable restoration company for this task.

 

Natural stone was the first building material used by man.  Its care and maintenance is one of the oldest tasks performed by our ancestors.  The above guidelines were developed by our years of experience with this beautiful material and with the addition of modern science will provide many years of beauty.

 

 

Written by

 

Frederick M. Hueston


Are you drowning trying to keep your Pool or water feature clean?

Are you drowning trying to keep your Pool or water feature clean?

By Frederick M. Hueston

www.stoneforensics.com            

 

Over the years my firm Stone Forensics has been called in to evaluate numerous stone and tile failures on pools, spas, fountains and other water features.  Failures such as tiles coming loose, grout missing, discoloration and build up of mineral deposits etc. In most cases all of these failures can be contributed to improper maintenance such as using the wrong chemicals to clean to unbalanced water chemistry. The following is a simple guide of what to do and what not to do when it comes to cleaning your pool or water feature.

 

Getting rid of the crud

One of the most common problems with swimming pools and water features is a buildup of mineral deposits. These deposits often appear as a white film deposited on the surface of the tile. These deposits can often develop into heavy crusts.  Most of the time the only way to clean these deposits off is to break out the Muriatic acid and go out with a scrub brush. The problem with most acids is that will attack the grout as well as the tile. I have seen cases where there was so much acid used in a pool that all the grout turned to powder and was washed away. If there is any marble in the fountain the acid will etch and dull the marble.  Most of these failures are the result of mis use of muriatic acid. So what is the proper way to clean these deposits off the fountain? The following is the proper procedure:

Procedure for cleaning mineral deposits off tile

Step 1.  Preparation. Before using any acid make sure to wear the proper protective equipment. For muriatic acid this would chemical resistant gloves, respiratory mask and goggles.

Step 2. Protect all adjacent surfaces that might be affected by the splash

Step 3.  Mix one part muriatic acid to two parts water. Make sure to pour the acid into the water.DO NOT Pour the acid in first and than the water. This could cause the acid to splash up.

Step 4.  Apply the acid solution with a sponge or rag. Do not use spray or pour it on.  Agitate with a nylon scrub brush until all the deposits are removed.

Step 5. Rinse the tile with a solution of water with once cup of odor less ammonia added to the one gallon of water. One cup of baking soda to one gallon of water will also work. This step is important since it will neutralize the acid.

Step 6. Rinse entire surface down with clean water.

The above procedure should reduce the amount of damage done. There are alternative non acid cleaning methods using bead blasting but this is not a do it yourself technique and will require a professional contractor.

Proper Water Chemistry

Another major problem with pools and water features is improperly balanced water chemistry.  The most common mistakes made are as follows:

  1. Not monitoring water chemistry frequently. You should be checking the ph, total hardness, bromine and chlorine at least twice per week. By monitoring these levels more often only minor adjustments will be necessary.
  2. Do not allow the ph to get about 8.0. When the ph increases. The activity of chlorine is dependent on the ph levels. For example when the Ph is 8.5 the chlorine is only about 10 % active but at 7.5 the chlorine is about 50-60% active. Keep this ph in check will prevent you from over chlorinating the water and will also save you money on chlorine
  3. Total Dissolved Hardness (TDS) and Calcium hardness are also important for water balance and can affect the precipitation of mineral deposits. These should be checked at least once per month. If the TDS is above 1500 ppm the water will need to be drained and replaced. This cannot be corrected with chemicals. This is a major cause of mineral deposits and staining on tile and stone in pools and water features.
  4. Alkalinity should be 80 to 140 ppm.  Lower or higher alkalinity will affect the effectiveness of chlorine or bromine levels. This should be monitored monthly as well.
  5. If you have a salt water pool the cells should be cleaned often. Corroded or calcified cells will reduce the amount of chlorine generated.
  6. If you pools filter system is a sand or DE filter try to avoid backwashing too often.  Most systems will only require backwashing when the gauge rises from 8-10 psi from clean
  7. Clean the filter baskets often. If these are clogged this reduces the amount of water flow and can cause not only poor circulation but build up of deposits, scum algae etc.
  8. If you use liquid chlorine add it in the evening not during the day.
  9. Brush the walls and tile both above and below the surface with a soft nylon brush. This will keep the deposits, algae and scum from adhering.
  10. Check for damaged tile and pipes.  You should be checking the pool on monthly bases for cracked tile and grout. Broken pipes etc.  These should be repaired immediately.

 

A properly maintained pool or water feature can go years without a major over haul or restoration. Of course you must start with the proper water balance and a sound water tight system.

If you run into problems or issues that are causing failures make sure to consult an expert to prevent further deterioration.


Are Floor Strippers Safe

Are Floor Strippers Safe

 

By Frederick M. Hueston

 

Almost all schools systems and public buildings apply acrylic finishes to there , terrazzo and stone flooring to keep them shiny and looking clean.  Often these finishes have to be striped off and a new finish applied.  The strippers that are used to remove these acrylic coatings often contain hazardous chemicals that are harmful to humans, animals and the environment.  The following information will explore how dangerous these strippers are and offer an alternative.

 

I examined the Material Safety Data Sheets(MSDS) of over 20 popular strippers used to remove acrylic floor coatings. I found that there are several common ingredients found which are the following:

 

Monoethanolamine

Butoxyethanol

Ethanolamine

Ethylene Glycol Monobutyl Ether

Sodium Hydroxide

 

I next examined the dangerous of these ingredients

 

Butoxyethanol

 

Butoxyethanol goes by several names including ethylene glycol monobutyl ether, ethylene glycol butyl either, ethylene glycol n-butyl ether, Butyl Cellosolve, butyl glycol, butyl oxitol,glycol butyl ether, Dowanol EB, Gafcol EB, poly-solv EB, and Ektasolve EB.  If you see any of these ingredients on an MSDS for the stripper you are using you are dealing with Butoyethanol.

 

Butoxyethanol is used  in many products other that floor strippers, including  paints, varnishes,  lacquers, paint thinners, agricultural products, herbicides, silicon caulks, cutting oils, fabric dyes and inks and household cleaners and even in some floor cleaners.

 

Butoyethanol is a dangerous chemical in many ways. It can pass into the air from water and soil as a vapor. This means that the vapors are emitted when you  mix your strippers in water and apply them to the floor.

 

Butoxyethanol is very harmful to humans and has been shown in laboratory testing to cause the following:

 Irritation of the nose and eyes

Headaches

A metallic Taste

Vomiting

Breathing problems

Low blood pressure

Lowered levels of hemoglobin

Blood in the urine

Metabolic acidosis

Birth Defects

Kidney and liver damage

 

Butoxyethanol and the Environment

 

Butoxyethanol can be absorbed by soil and can make its way into the water supply.

 

 

The warnings on many labels of floor stripper containing Butoxyethanol say the following:

 

Avoid breathing vapor or mist.
Avoid contact with eyes, skin and clothing.
Keep container closed.
Use only with adequate ventilation.
Wash thoroughly after handling.
Keep away from heat and flame.

 

Do you want this harmful chemical used in your school or building?

 

 

Monoethanolamine

 

Monoethanolamine is another common chemical found in strippers.

 

Monoethanolamine also goes by several names such as  Colamine, Glycinol, Olamine, Ethanolamine, 2-Aminoethanol, 2-Hydroxyethylamine, beta-Ethanolamine and beta-Hydroxyethylamine.

 

Some of the potential health effects include the following:

 

Extremely harmful to the eyes.

Harmful to lungs, skin.

Tissue damage can occur around mucus membranes

Can cause burns on the skin

Maybe toxic to Kidneys, Lungs, liver and central nervous system.

 

Monoethanolamine in also combustible.and corrosive

 

Harmful to animals and the environment.

 

Monoethanolamine can produce very harmful byproducts due to degradation in the environment.

 

Sodium Hydroxide

 

Another chemical found in many strippers is Sodium Hydroxide.  Sodium Hydroxide

Is commonly known as lye. Any one who has ever worked with this knows it can easily burn you skin, not to mention what it can due to your eyes and mouth.  It is classified as a poison and is very corrosive.

 

Since it is a poison it is harmful to animals and fish.

 

 

Conclusions and Alternatives

 

As you can see the common chemicals found in numerous stripper formulas are not safe for humans or the environment and cannot be classified as a sustainable practice if using them.

 

The good news is there are alternatives to these chemicals.

 

Acrylic coating on terrazzo and stone flooring can be removed mechanically with abrasives using no chemicals other than water.

 

Many Chemical companies are manufacturing strippers that are safe to work with and are Green Certified.

 

 

 

 

 

 

 

 

 

 


A New But Old Polishing Procedure for Natural Stone/Terrazzo Flooring

A New But Old Polishing Procedure for Natural Stone/Terrazzo Flooring

By Frederick M. Hueston 

Putting New and Old in the same sentence is somewhat of an oxymoron. But in this case  both of these adjective apply. What I am talking about is a polishing system for stone flooring that was used many years before chemicals came into existence and is now fast becoming  the preferred method specified by architects and others.   The word   “Green” has entered our industry and I am finding that many projects across the US are now specifying that a green and sustainable restoration process be implemented in restoring both natural stone and terrazzo surfaces.   This article will present not only what is sustainable but will give you an alternative to traditional polishing methods that is fast becoming the preferred method.

 

What is Green?

Everywhere you look individuals, government agencies, universities and schools and even private businesses are going green.  As we hear news about global warming and how we are polluting our own environment, it is of utmost importance that we all do our part in saving our planet not only for our present generation but for generations to following.

What Does Going Green Mean?

The term Green or Going Green has entered our vocabulary but few really know what the term means. Going Green is principles that minimize the use of nonrenewable resources and seek to prevent air, water and ground contamination and other activities that degrade the environment.  According to The US Green Building Council worldwide buildings account for 17% of fresh water withdrawal, 25% Wood Harvest, 33% CO2 emissions and 40% material and energy use.

Going Green is simply changing the way we build, operate and maintain buildings to reduce the negative impact it is having on our environment.

Many small businesses feel that they are too small to make an impact on the environment. Even individuals feel the same. Take a look at the following facts and you will see this is simply not true.

·        A single quart of motor oil, if disposed of improperly, can contaminate up to two million gallons of fresh water.

·        A 1/32" leak in a faucet can waste up to 6,000 gallons of water a month, or 72,000 gallons a year.

·        Americans throw away 25 billion Styrofoam coffee cups every year, and 2.5 million plastic beverage bottles every hour.

·        The amount of wood and paper we throw away each year is enough to heat 50 million homes for 20 years.

 

And the list goes on and on.

 

 

Stone Restoration and Green

Traditionally the  restoration, repair and maintenance of stone and terrazzo surfaces use chemicals that are harmful to the environment and to people in general. Chemicals such as polishing compounds contain harmful acids. Solvent based cleaners and sealers emit harmful VOC’s. Not to mention the carcinogens and toxic effects many of these chemicals have on humans.   The procedures used to restore stone surfaces also produce a copious amount of waste and use large amounts of fresh water.

I am currently working with a stone restoration company that is taking steps to eliminate all these harmful chemicals and processes. This company has developed methods to restore , repair and maintain stone surfaces using no harmful chemicals. As matter of fact the restoration and polishing of marble, granite, limestone and terrazzo uses no chemicals at all. Here is a summary of their process

The floor is ground and resurfaced using a fixed diamond abrasive and water. These abrasives are similar to sandpaper but differ in that there is no grit removed or left behind on the floor. The diamond abrasive is fixed to a pad. There are no chemicals used at all.

The water used will be recycled and reused in a specially designed system.

To polish the stone or terrazzo super fine abrasives are used. These abrasives contain no harmful chemicals.

Many stone restoration and janitorial companies are also using floor finishes to achieve a high luster on the stone or terrazzo surface. In addition to these finishes containing chemicals that are harmful to the environment. They also have a negative impact on the esthetics of the surface in the following ways:

-Most finishes used on stone and terrazzo are soft and tend to show wear and scuff marks in a very short time. This increase the amount of maintenance as well as cost for daily maintenance

-All floor finishes at some point will need to be stripped off. The chemical strippers used are caustic and can cause damage to the stone or terrazzo, not to mention the environmental impact.

-The old finish once it is removed will need to be disposed of. Most of these waste finishes are considered a hazardous waste.

-Most finishes do the opposite of what they are designed to accomplish. That is they become a dirt magnet.  I have conducted experiments that show a coated surface will attract more dirt than a surface restored using a green system.

Even today’s stone restoration companies are using polishing compounds that contain dangerous oxalic acid.

A Green stone and terrazzo restoration process have no negative impact on the building environment or the occupants since  no chemicals or finishes are used. The maintenance requirement after the stone or terrazzo is restored is reduced by as much as 50% or more saving on labor and chemicals.

 

 

Objections:

There are many professional stone restoration companies as well as others who will object to the fact that stone can be restored, polished or maintained without some chemical procedure. The following are some of these objections:

 

Stone cannot be polished without the use of chemicals?

Many stone restoration companies will argue that it is impossible to achieve a deep high reflection on natural stone without the use of chemical polishes. This in fact is not true.  Mechanical polishing using diamond abrasives alone with the proper equipment can achieve results that are as good as or superior to chemical polishes.  There are several great examples of this. Take a look at the floors at Syracuse International Airport and Chicago Ohare and you will some great examples of sustainable polish. In addition I have worked with several school systems that have their terrazzo floors polished with this method.

 

It costs more to go green?

Again this is not true. As a matter of fact going green cost a lot less. This is especially true after the stone is restored and needs to be maintained. An independent study shows that the payback is under 3 years with a saving of around $1.85 per square foot per year.

As a small Contractor I can’t afford the large machines necessary to do this work?

I will not disagree that it takes large machinery that is expensive. In fact for small residential and commercial projects these large machines will be impractical.  However, technology is advancing and there are now diamond abrasives that will achieve a polish equal to or greater than a polish achieved by chemical methods.  I am old enough to remember when there used to be small corner grocery stores all over the US. Today the large chains have put these small stores out of business. I’m afraid this is what will happen to the small contractor if they don’t keep up with current methods and seek to develop sustainable methods to compete with the larger companies.

Even with small to medium hotels etc, it is impossible to use 220 V or three phase machines since they will require a large generator that is too noisy for these facilities?

Again, I cannot agree more and this is why there are propane powered machines available. These machines are quiet and are rated by EPA and OSHA to be used indoor. I know of several contractors who are using these  machines and methods vey successfully in small to medium size buildings.

Times are changing and technology is advancing. Sustainability is fast approaching and in no time it will be required in many states.  Yale University has already put policies into place that ban the use of any chemicals for not only restoration but for  maintenance. Several states now have legislation in place that will mandate that sustainable methods be used in maintaining flooring surfaces. 

The small contractor that fails to see the future and at least be aware of these advances will be zapped back to the Stone Age and struggling like a caveman hunting for his next meal.

 

Be Wary of Green Washing                                                                                                                                                                            

Caution must be exercised when looking at what constitutes a “green” product. Many chemical companies have reduced the percentage of hazardous chemicals in their formulations. However this does not make the product any safer. Many articles have discussed this and have called it Green Washing. A great example of this is in a article by The Environmental Working Group(www.ewg.org/schoolcleaningsupplies , which  uses the cleaner Simple Green as an example.  There article states that  Simple Green claims to be non-toxic and biodegradable but fails to mention that the principal cleaning ingredient it contains is a possible human carcinogen. The hazardous ingredient is still present along with all the dangerous it exhibits.  To be totally sustainable it is best to use NO CHEMICALS at all.


Thursday, July 2, 2020

Tile Bond vs Coverage

Tile Bond vs Coverage  

Frederick M. Hueston, Stone Forensics

 

Experienced installers and inspectors are aware of the requirement for coverage on stone and tile installation. ANSI requires an 80% coverage in dry areas and 95% in wet areas for ceramic tile as follows:

 

ANSI A108.4- Installation of tile for floors and countertops

               A-4.2.2.4.2 Thoroughly beat all tile or tile assemblies into place with a beating block to obtain maximum contact of adhesive on the back of each tile, or back of each tile and back mounting material, and not less than an average contact area of 80% except on shower installation where contact area shall be 95% when no less than three tiles or tile assemblies are removed for inspection.

Many local and state codes also require the same coverage.

 

Natural Stone guidelines set by The Natural Stone Institute and the Tile Council of North America require 95% coverage in all areas.

So coverage is nothing more than the amount of setting material touching the back of the tile. No where in the industries guidelines does it state a percentage of bond.

Bonding is defined as something to join two things together. In the case of tile setting it would be to join the tile to a substrate via an adhesive.

But is coverage and bonding the same.  I would argue that the two are not necessarily the same or in some cases not even related.

For example, a tile set in a sand bed would have 100% coverage but zero bond. On the other hand a quarter size dot of epoxy on the back of a tile would make it almost impossible to pull up which means it has a good bond.

As long as the proper adhesive is used a high coverage percentage can have a high bond strength, but experts need to be cautious when describing tile failures and not to confuse coverage vs bond. This is something I run across all the time where experts confuse the two terms. 

As many experts are aware there all kinds of bond failures that do not relate to coverage. Some examples are as follows:

1.      Incorrect setting mortar or adhesive. This is especially true when standard thin sets are used on resin back tiles.

2.      Bond breakers on the tile- Dust, sealers, curing compounds and other materials that can interfere with bonding often result in lack of bond

3.      Skimming over- This is when thin set mortar is applied to the substrate and it starts to cure before the tile is set.

4.      Improper mixing- Improper mixing of the setting mortar and/or adhesive can result in poor or no bond

5.      Flash setting due to hot substrate

6.      Improper beat in

7.      Failure to clean back of the tile

8.      Improper dilution of additives in the setting mortar

These are just some of the common reasons for bonding failures. Non of them can be contributed to coverage.

Failures that can be caused by poor coverage are the result of voids in the setting mortar or adhesive and can include:

1.      Cracking

2.      Hollow sounds

3.      Water intrusion in the voids of the setting mortar

These failures are related to coverage but not to bonding.

 

In conclusion one needs to be aware of the differences between bonding and coverage failures.


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