Removing Urine Stains and Odors from Stone Surfaces

Removing Urine Stains and Odors from Stone Surfaces

Frederick M. Hueston, Stoneforensics.com

 

Your new puppy made a mess on your new marble floor. The granite floor in front of the urinals in the men’s room is stained and smells of urine. These are just a few of the issues with odors emitting from your stone surfaces.  Weather it’s your puppy or your husbands poor aim the following should remove the stain and the odor.

The Chemistry of Urine

Urine is unique in that it is a substance that comes our of the body as an acid and when it starts to dry becomes an alkaline crystal. For you amateur chemist it starts at a pH of 5-6 and converts to a pH of 10-12. These alkaline crystals are hydrophilic which simply means they absorb moisture. As these crystals absorb surrounding moisture the stain can grow in size. If the stone is a polished marble or limestone it can become dull due to the initial acid reaction but can also dull from the strong alkali. If this is the case the stone may need to be repolished.

Removing the Stain

Removing urine stains can be tricky and timing is everything. The quicker you can get to the stain the easier it will be to remove.

As soon as you can blot the urine up with some dry paper towels. Do Not wipe since this will only spread the stain.  Clean the stain with some dish soap and water. Mix about one teaspoon of dish soap in a gallon of water. Apply this solution on the wet area and allow it to sit for a minute or two. Blot the solution up and rinse with clean water. If there is still a stain, then you will need to apply a poultice.

 

The following is a basic procedure for stain removal More detailed stain removal instructions can be found here. http://stoneforensics.blogspot.com/ or www.SurPHaces.com

 

What you’ll need:

1.     Flour(use only white flour)

2.     Hydrogen Peroxide 20 Volume(You can purchase 20 volume peroxide at most beauty supply stores)

3.     Plastic wrap (saran wrap or equivalent)

4.     Plastic putty knife

5.     Low contact painters’ tape

6.     Mixing bowl or cup

7.     Plastic or wooden spoon

 

 

1. Wet the stained area with distilled water. Pre-wetting fills the pores of the stone with water isolating the stain and accelerating the removal by the chemical.

2. Prepare the poultice.  Take a small amount of flour and pour the peroxide into the flour and stir until you reach a creamy consistency.

3, Apply the poultice to the stain being careful not to spill any on the non stained areas. Apply approximately 1/4-inch thick over-lapping the stain area by about one inch.

4. Cover the poultice with plastic (food wrap works great). Tape the plastic down to seal the edges. It also helps to poke several small holes in the plastic so that the powder will dry out. Failure to do this may result in the poultice staying wet.

5. Allow the poultice to dry thoroughly. This is a very important step. The drying of the poultice is what pulls the stain from the stone into the poultice material. If the poultice is not allowed to dry, the stain may not be removed. Drying usually takes from 24 to 48 hours.

6. Remove the poultice with a plastic putty knife. Rinse with distilled water and buff dry with a soft cloth. If the stain is not removed, apply the poultice again. It may take up to five applications for difficult stains.

Step 2 Odor removal

 

Once the stain is removed the urine smell may still be present. The following is how to neutralize the odor:

The nasty smell you experience is the result of bacteria using the urine as a food source. So, in order to eliminate the odor we need to kill the bacteria. There are numerous products out there that are designed for eliminating the odor in carpets. These same chemicals can be used for stone.  If you use these products make sure they are enzymatic. Many products are only mask the odor, you want to eliminate it, so an enzymatic product is necessary.

 

Instructions for applying an enzymatic cleaner

 

• Spray the affected surface liberally with the cleaner using a pump sprayer or spray bottle.
• Cover with plastic  for 1 to 2 hours to slow the evaporation rate and allow time for the first application to soak deeply into the stone.
• Note that as the first application of cleaner goes to work, the urine odor may intensify at first. This is typical with old or heavy urine deposits and indicates that the urine being loosened and is rising to the surface.
• Remove the plastic and blot the floor dry with paper towels or cloths. Expect the blotting towels or cloths to be colored yellow and smell heavily of urine. Dispose of the soiled towels or cloths.
• Reapply the cleaner. Allow to dry 1 to 2 hours. (In humid climates lacking AC, drying may take longer.)
• Reapply as needed, with 1 to 2 hours drying time between applications, until odor is removed.

 

The above processes are time consuming but will be well worth the effort if done properly.

 

 

 

 

Removing Ivy and Other Vegetation from Brick and Stone Walls

Removing Ivy and Other Vegetation from Brick and Stone Walls

Frederick M. Hueston

 

Ivy growing on the side of a home or building ads a unique look, however the tendrils or aerial roots can grow into the brick or stone work causing it to flake and fall apart. If you decide to remove the vegetation from the wall it needs to be done carefully to not further damage the masonry. The following is a procedure that should remove the ivy safely.

 

Before attempting any removal make sure you are wearing the proper personal protective equipment such a glove and googles.

 

Step 1. If there is any living ivy it will need to be killed using a weed remover such as Round Up of similar product. Looking for a product that contains Glyphosate.  Spay the ivy making sure to saturate it. It may take several days for it to complete turn brown. Reapplication may be necessary. Make sure to do this in dry weather to give it time to work.

Step 2. Once all the ivy is dead cut the main trunks with a saw or shears as close to the ground as possible.

Step 3.  Remove as much of the top growth as possible with shears. DO NOT pull the ivy. Pulling can cause additional damage to the brick or stone.

 

Step 4. Once all the top growth is removed scrape the remaining aerial roots with a putty knife. Be careful not to dig the putty knife into the brick or stone. Hold the scarper at a 30 degree angle.

 

Step 5. Remove any remaining aerial roots with a wire brush.

 

Step 6. Rinse the brick and stone with clean water.  You can scrub with a soft scrub brush if desired. DO NOT use a metal brush with water. Use only a nylon brush

Step 7. Clean the brick or stone with a good quality stone cleaner.

Step 8. If repairs are needed than I would call a reputable stone restoration contractor. Repairs are not a DIY project.

 

 

 

I repeat..>DO NOT yank or pull the ivy off the wall. Otherwise you will pull apart the brick or stone.

Difficult aerial roots can be burnt off with a torch.

Is it a Crack or a Fissure on my Stone Countertop

Is it a Crack or a Fissure on my Stone Countertop

Frederick M. Hueston

 

You wake up one morning and go into your kitchen to pour a cup of coffee and you notice a long pattern on your granite countertop that looks like it cracked.  You run your finger across it and wonder if it was always there or just occurred overnight.  Later that morning you call the fabricator who installed it, send him a picture and he says its just a natural fissure.  You have your doubts and wonder if there is way to tell the difference between a fissure and a crack. The following should help you decide if your granite, marble or quartz is cracked or if it’s a natural fissure..

First, almost all-natural stone has some degree of fissuring or veining.  In layman’s terms fissures and veins are inherent elongated openings in stone resulting from geological formation, environmental impact, mineralogical crystallization, and other factors.  They are sometimes referred to as “hairline cracks.”  The even smaller micro-fissure is only detectable through a microscope. 

Fissures or veins usually have minimal unevenness, chipping, separation, movement, and fracturing.  Field measurement of a fissure’s width is difficult and prone to error.  A slight break in the reflection, an indentation and a less reflective finish are three factors that mostly indicate the presence of a fissure.

On the other hand, cracks are quite different than fissures and its indicators are readily apparent.  Cracks usually have noticeable unevenness, chipping, separation, movement, fracturing, and obviously broken pieces of stone.  With stress carefully placed on the area in question, movement leading to additional chipping and fracturing may be evident.  Also, noticeable separation allows an accurate measurement of the width.   Cracks are generally caused by mishandling or from improper support.

 

How to tell the difference

One test to perform is to see if your fingernail catches across the crack.  Gently run your fingernail across the vein/crack. A natural fissure and a vein will not catch. If your fingernail catches it is most likely a crack.

Another indication that it is a crack is to see if the suspected crack runs through or around individual crystals in the stone. If it run across and crystal it is most likely a crack. If it runs around the crystal it can be a fissure. 

Of course there are exceptions to these rules and if in doubt consult a an expert who can do an evaluation to be sure.

 

The Care and Feeding of Slate Flooring( Wiping the Slate Clean)

By Frederick M. Hueston, Technical Editor

Slate flooring is become increasing popular in the US today. Years ago slate was basically gray and pale and there weren’t many varieties to choose from. Today there are literally hundreds of slate colours. In India alone there are several hundreds running every imaginable color and well as texture.  The problem with slate for flooring is that it differs somewhat from the typical highly polished marble, limestone and granite. This article will explore the proper care and feeding of slate flooring. Sections of this article can also be used to give your customers so they know the proper care of their new slate flooring.

 WHAT IS SLATE

 Slate is a stone, which has been metamorphosed from shale—that is, it consists of clay-like materials that have undergone change under heat and pressure.  In other words, slate can be recognized by its sheet-like structure.  The material is usually thin and if broken in half, will flake off into sheets.  Slate is seldom highly reflective unless a coating is placed on it, and its surface is usually uneven unless machine- sanded.

Although slate can be purchased in 12" x 12" tiles, the most popular size is random patterns of varying shapes.

 For those of you who would like to know more. Slate is made up of minerals of quartz and illite. You will also find minor amounts of mica, calcite and other mineral.  Red colored slates contains hematite, which gives it is red color. Greens contain chlorite and blacks and grays contain carbon and or graphite.  The reddish tans are the result of iron oxides.

 BASIC SLATE FLOOR CLEANING

           OK, lets get down to what this article is all about—the actual care and maintenance of your slate flooring. It is not a complicated subject.  In fact, most of the mistakes that are made, and the main reason slate flooring gets dirty or ruined can be traced to simple neglect.

          Let’s suppose you’ve just purchased a brand-new car—and you never wash it. Soon enough the paint will fade, the body will rust, and the car will cost you a small fortune to restore.  On the other hand, if you make the effort to wash it on a regular basis and throw a coat of wax on it every now and then, it will look as good as new for years.  This is exactly what you need to do for your slate flooring.  Keep it clean and protected, and it will last till the kids move out—and may even be around when they move back in. The following maintenance tips will tell you what you need to know to make this possible.

     

 DAILY CLEANING

 

          To keep your slate flooring in tip-top condition, a few simple maintenance procedures are necessary.  For best results, they should be followed very closely.

 DUST-MOPPING

          Of all the procedures used to maintain slate flooring, dust mopping is probably the most important.  Dust, dirt and grit are what cause most surfaces to scratch & mar; if we could somehow eliminate them, this would cease to be a problem.  Several studies have indicated that floors, which are dust-mopped often, stay cleaner and shinier longer.

           Do dust mop your floor daily.  If traffic is heavy, or the floor is located in a commercial building, do it several times a day. Remember do not use oil-treated dust mops on slate flooring.

           When dust mopping, be sure to run the dust mop in one direction only. Do not move it back and forth.  Think of it as pushing the dirt in only one direction.  When you have accumulated enough dirt and debris, pick it up with a dustpan and brush and take the dust mop outside to shake any remaining dust.  When storing the dust mop, be sure to keep its head off the ground. Hardware store sell various hangers, which are excellent for storing mops and  brooms.

           Designate only one dust mop for each type of surface.  For example, you should use one dust mop for your slate flooring and a separate one for other tile or wood floors.  Do not get the dust mop wet; if the floor is wet, be sure to dry it before dust mopping.

           Purchase a good-quality machine-washable mop and keep it clean. Wash it in cold water with laundry detergent and machine-dry.

 WELCOME MATS, RUGS, AND WALK-OFF MATS

          Another important tool necessary for keeping dirt and debris off your slate floors is some type of mat, rug or what is commonly called a walk-off mat.  A good-quality mat will capture dirt before someone walks on the floor.  If it is placed outside your door, it is only human nature and common courtesy for people to wipe their feet before entering the house.  Studies have shown that it takes approximately seven steps to remove most loose dirt from one’s shoes.  For this reason, I would recommend placing mats both inside and outside.

 

 MAT AND RUG TYPES

           There are hundreds of mats and rugs on the market today.  Be sure to purchase one of good quality. Be careful about using rubber- or jute-backed mats or rugs on slate flooring; either kind of backing can bleed into the slate, causing a stain that may be difficult or impossible to remove.  A mat should be at least as wide as the doorway it serves.

           Clean your mats often, daily if possible. Take them up and clean under them when you dust mop.  Be sure the floor is dry before returning them to the floor. Never place a mat down on a wet surface or put a wet mat on any surface.

 DAMP OR WET MOPPING 

           All slate flooring needs to be cleaned. How often you will need to damp or wet mop will depend on  the amount of traffic and the finish (honed, coated, textured).  The following frequencies are recommended:

 

Residential: Once a week

Light commercial: Twice a week

Heavy commercial: Daily

 

 

          These are only recommendations; you will need to adjust the frequencies to suit your own conditions.  For example, during a heavy rainstorm, dirt is tracked onto the floor and should be mopped up as quickly as possible.

  

REMOVING OLD WAX FROM SLATE FLOORING

           Suppose your slate floor  has been covered with a wax or some other type of coating. How do you remove this coating, and what chemicals should be used?  The procedure used to strip a slate floor is relatively simple, and is outlined below. But before you run out and buy a chemical floor stripper, it is important, as always, to  find out what is on the floor.

  WHAT'S ON MY FLOOR?

           Today’s technology has delivered  hundreds of different types of floor coatings—natural and synthetic waxes, acrylics, thermoplastics, polyurethane’s, epoxies, etc.  To choose the proper chemical for removing them, we must know what type of coating we are dealing with. I suggest the following procedure:

           1.  If you already know what coating is on the floor, contact the product’s manufacturer for removal instructions.

           2.  If you have no idea what is on the floor, perform the following test. Mix one cup of household ammonia in one gallon of warm water; pour a small amount of this mixture on the floor and agitate with a soft scrub brush. Pick up the solution with a wet vacuum or a dry rag.  Examine the area; if you have removed the coating, you will need to use a commercial wax stripper to remove the remaining wax. These coatings are water based and are easily removed with commercial strippers.  Visit your local janitorial supply house and ask for an alkaline acrylic finish stripper.  If the coating has not been removed with the ammonia, there is a good possibility that the finish is urethane- or epoxy-based.   What this means is that some very strong solvents will be needed to remove the finish. At this point, it might be wise to call in a professional.  If you wish to attempt stripping these urethane-based coatings yourself refer to the stripping procedure in this book.  It is common to find urethane-based coating on slate flooring. They can be very, very difficult to remove. The removal process may be so aggressive that the surface  may become damaged. Always test a small area first to make sure you get the desired results.

  STRIPPING PROCEDURE(Acrylics)

 

          To strip a slate floor with commercial alkaline strippers, use the following procedure. A janitorial floor-buffing machine and a wet vacuum are highly recommended. Before setting up to strip the slate be sure to remove all furniture and protect painted surfaces such as baseboards with plastic drape.

 

          1.  Mix the stripper solution in a separate bucket, following  the instructions on the label.

 

          2.  Apply the mixed solution with a string mop to one small section at a time.  Do not apply more than can be scrubbed effectively.  Let the stripper sit for several minutes; this will allow the chemicals to break up the coating.  If the stripper begins to dry, add more of the solution to keep it wet.

 

          3.  Scrub the floor using a 175-rpm standard buffing machine equipped with a black stripping pad or stripping brush (pads and brushes are available at most janitorial and rental supply houses). Continue scrubbing until the coating breaks up.  Some slate may be scratched by stripping pads and brushes; always test a small area first before proceeding with the entire project.  If the pad scratches, your janitorial supply house can  recommend a softer pad or brush.

 

          4.  Pick up the solution with a wet vacuum and rinse immediately.  Use a separate string mop, bucket and wringer for your rinse water. 

          5.  Examine the area thoroughly. If any of  the coating is still present, re-strip.

 

          When you’re through, be sure to rinse the floor thoroughly; most alkaline strippers have a tendency to leave a film. Adding several ounces of a good neutral cleaner or stone soap to the rinse water will help neutralize the stripping solution.

If a coating is to be applied, re-apply according to manufacturers instructions. If a penetrating sealer is to be used, make sure the floor is thoroughly dry.  Allow at least 24 hours before sealer application.

 

 STRIPPING PROCEDURE(Urethanes)

 

          To strip a slate floor that has a urethane coating, use the following procedure.  Before setting up to strip the floor be sure to remove all furniture and protect painted surfaces such as baseboards with plastic drape.

 

Caution: Some of the strippers for removing urethane contains solvents such as methylene chloride that is extremely dangerous to work with.  Make sure to wear protective clothing and goggles and to ventilate the room to avoid being over come with fumes. Many of these strippers also require you to wear a respirator.  These strippers will damage all surfaces so make sure everything is protected. If you do not feel comfortable with these procedure, I recommend you contact a professional.

There are also what are known as “safe strippers” available that do not pose as much as a danger but they take a very long time to react. Some of these strippers require as much as a 24-hour dwell time to remove urethane effectively.

 

          1.  Apply the stripper with a paintbrush or roller. Apply liberally and try not to reapply once you have place the stripper down.  Most of these strippers are in a form of a thick paste..

 

          2. .  Let the stripper sit for several minutes to several hours; this will allow the chemicals to break up the coating. Do not scrub the floor with brushes or a floor machine.  These strippers are flammable and machinery should not be used.  You can tell when the stripper is working by a bubbling or softening of the coating. Take a metal putty knife and try scraping the coating. If it is soft and easily comes off, then it is ready to be removed.

           3. Scrape the coating with a putty knife and place the soften coating into a metal bucket. These materials will need to be disposed of in an approved hazardous waste container and will need to be picked up by a hazardous waste company.  Refer to your yellow pages under hazardous waste. Some counties and cities also will take these containers. Call you’re your local county government and ask how to dispose of these materials.

           4. Once all the coating has been removed restrip the slate as outlined above using a commercial floor stripper for acrylics . 

           5.  Examine the area thoroughly. If any of  the coating is still present, re-strip.

           When you’re through, be sure to rinse the floor thoroughly; most alkaline strippers have a tendency to leave a film. Adding several ounces of a good neutral cleaner or stone soap to the rinse water will help neutralize the striping solution.

If a coating is to be applied, re-apply according to manufacturers instructions. If a penetrating sealer is to be used, make sure the floor is thoroughly dry.  Allow at least 24 hours before sealer application.

  

Important- it is very important that the slate is thoroughly dry before applying any finish. Placing a coating on wet slate will cause the coating to turn a milky white color.

         

Stone Myths

Stone Myths

 Over the past 20years I have heard many stories about the reasons stone will fail, turn color, fade or what ever. Many of these stories are funny and almost all of them are just plain false. The following is a brief synopsis of these stories and myths along with the real reason for these conditions.

 

Green Marble warping;

Many season installers who have tried to install green marble tiles with ordinary thin set or other water based setting materials have experienced warping problems.  I cannot tell you how many times I have encounter the same problem as an inspector. The following are some of stories I have heard for the reason that green marble will warp.

 “Green Marble will warp because it contains living plant material. As water is added to the marble the plants start to grow and this makes the marble warp.”  This is an absolute true story. I heard an installer telling a customer this and about fell to the floor, trying not to laugh. When I asked him if he was kidding, her said no and really believe this was the reason.

 “Green marble will curl on the edges because the installer did not put enough setting mortar on the edges. The green marble will have a tendency to lift off the floor where there is not mortar and hence it will curl.”  This falsehood isn’t as bad as the first one, but it is just as wrong.

 FACT:  The real reason green marble warps is a condition known as hysterisis. Green marble’s are very sensitive to moisture and what happens when water enters the stone, it causes the marble to release any internal stress it has and hence it warps.

  Your Stone Floor has an Effervesce problem,

 The key word here is effervescence. I have lost count on how many times I have heard contractors refer to efflorescence as effervescence. Lets clear this up right now. Efflorescence is the deposit of soluble salts on the surface of the stone. It is caused by water that carries the salts from the setting bed or the stone to the surface; it is often deposited as a white powder like residue on the surface of the stone. Effervescence is what happens when something fizzes. A good example is when one drops an alkazelser in a glass of water. The fizzing is referred to as effervescence.  I have never seen a stone effervesce, unless someone was pouring acid on it.

Along the same topic I have had so-called experts instruct people who have an efflorescence problem to seal the stone to help it. This is wrong, sealing will only block or reduce the pore size of the stone and this in turn will not only cause more efflorescence, it could also cause spalling.

 Your Stone Floor needs to be homed!

 No, this is not a spelling mistake, the word use was HOME.  I have run into several sales people who have called the honing process, homing.  Maybe they also worked with pigeons , but I have never heard of homing a floor. The proper term of course is HONE, which means to abraded a stone.

 That’s not a crack, it’s a fissure!

Now I don’t want any letters or emails from you fabricators out there. The following is an explanation of both of these terms. Many fabricators will try and  blame cracks that occur in stone installations on natural fissures that occur in the stone. Sometimes they are right and sometimes they are wrong. If one looks up the word ‘fissure” in the dictionary, guess what? A fissure is a crack. What I believe most fabricators need to do is describe the natural fissures in the stone as “natural occurring as part of the formation of the stone.  Cracks on the other hand should be called “Breaks” caused by external forces on the stone. This would mean that if someone stands or sits on the stone, it could develop a break.  Of course, the most likely place for a break to occur is on a natural fissure. For this reason it must be handled carefully and the stone needs to be examined carefully.

This is a tricky topic and is open for debate, however, you need to communicate to your customer what the difference between natural occurring fissures and those caused by external forces.

 Vinegar and water

 To clean your marble or limestone, just use some vinegar and water. Now, hopefully most of you in the stone business know that vinegar is an acid and it will etch calcium based stone. However, I cannot believe how many times I have heard tile installers make this recommendation. In case you don’t know…never, never use vinegar on any stone surface. Marble and limestone’s are generally the most susceptible but there are also some granite that will become damaged from vinegar.

 

 To remove oil from stone saturate it with water and the water will force the oil out.

I heard this one recently from one of my students who told me that some expert told him this is how you remove oil stains out of stone.  Believe me, it does not work. In theory since oil will float on water you would think that this makes sense. However, the oil is trapped in the pores of the stone and no amount of water is going to force it out. The best way to remove all is with a poultice and a degreasing chemical. For instructions on poulticing see our web site at www.ntc-stone.com.

 

 All Marble have Veins

 This is another fib I hear all the time. Many people in our industry believe that if a stone has veins then it must be marble. Of course this is totally false, since veins can be observed in granite and limestone as well.

The Darker the stone the softer it is!

Again, Untrue. There are some really dark granites that are as hard or harder than some of the lighter colored granites. The same can be true for marble and limestone.

 Of course we should not forget the myths about granite harboring bacteria and emitting harmful radon gas. In past articles I have dealt with both of these falsehoods. Here is a brief summary.

 

 There is a report circulating that granite countertops are unsafe, harbor bacteria and can produce disease. This is absolutely FALSE, NIOSH and the CDC have no reports of granite or any other stone used as a countertop as being unsafe. Think about this for a moment, if stone was unsafe and unsanitary why would there be cutting boards sold made of stone. Why would stone be used in food laboratories. There has been no known proof of any illness caused by using stone as a countertop.

 There have also been rumors that granite contains harmful radon gas. This again is untrue. There is so little radon in granite that one would have to live to be 10,000 years old for it to have an ill effect.  There is more likely more radon coming from the ground and the concrete that your house is built on.

 As the years progress and I get grayer, I hear more and more falsehoods and myths. I keep readers posted any new ones I hear.

 

 

Are your Ice and Snow Melters Destroying your Stone and Terrazzo Floors

Are your Ice and Snow Melters Destroying your Stone and Terrazzo Floors

     The Deterioration of Stone & Masonry through the Crystallization of Deicing Salts

                                                            Frederick M. Hueston                                                                      

 The crystallization of deicing salts found in many snow and ice melter can cause severe deterioration of stone, terrazzo and masonry surfaces. This crystallization is called subflorescence.  Snow and Ice Melters containing Calcium Chloride, etc are the cause for this damage. .Problems associated with subflorescence can be diagnosed and identified by visual clues, such as spalling and pitting.  Accurate diagnosis of subflorescence can be confirmed with laboratory testing. Preventative applications might include application of chemical injection and coating the masonry with a sealer or impregnator as well as switching to a snow and ice melter that contain non-crystalline salts. The following article will explore the problems caused by these deicers and what can be done to prevent damage to your stone, terrazzo or masonry floors.

 How do Deicer Cause Damage                                                                                                                                                                                                                                                                                                  The deposit of salts in the pores of stone and masonry is the major cause for deterioration of these surfaces.  These salts are contained in many popular snow and ice melters.    Boyer(1986) contributes  deicing salts

            When snow and ice melts the salts used in deicers become soluble. The water wicks into the pores of the stone and masonry carrying the salts with it. When the water evaporates the salts recrystallize. The pressure created in the pores of the stone and masonry cause the surface to flake off or spall. This process is known as subflorescence.          

                                                                                                                                       4

 Diagnosing and Identifying Subflorescence

An experience stone consultant can recognize the signs and symptoms of damage caused by deicing salts. The stone and masonry will appear pitted(spalled). This damage is observed in the walking path at the entrances of the building. The damage tends to lessen the further away from the entrance. Certain stones such as some limestone’s and slates will flake off in sheets. Terrazzo and marble will become pitted.

Core samples can also be taken and sent to a lab for testing and verification if necessary.

 Snow and Ice Melters

There are many brands of snow melters on the market. Many of these melters contain salts that will crystallize and cause damage to stone and masonry. The following are the salts you should avoid.

Rock Salt- Rock salt will go by the name of Halite but chemically it is simply Sodium Chloride(NaCl). This is the most common salt sold for deicing and it is also the least expensive and hence is the most widely used. It is also the salt that causes the most damage to stone, terrazzo and masonry flooring.

Calcium and Magnesium Chloride(CaCl2 –MgCl2)- these are salts that come from natural salt deposits in the Great Salt Lake in Utah. They are also destructive to stone, terrazzo and masonry. They also can deposit a film on the surface of the floor causing it to be slippery.

 Potassium Chloride(KCL)- This salt is not a very good deicer by itself and is often found mixed with other ingredients. It is often sold as a safer salt for plants. But not for stone, terrazzo or masonry.

 Ammonium Sulphate(NH₄]₂SO₄    Stay far away from this salt. It is very damaging to stone, terrazzo and masonry. It’s not used that much in deicers but if you see it listed on the ingredients, don’t buy it.

 Urea- Urea is commonly found in fertilizers. In its pure form it is less damaging the most other salts. Most deicers containing Urea are not pure and can be damaging to stone, terrazzo and masonry.

The above salts are in a sold crystalline form. There are liquid deicers available containing Ethylene Glycol and Potassium acetate but liquids are usually impractical to apply in schools and other public buildings.

 Safe Deicers

Which salts are safe for stone, terrazzo and masonry flooring?  Thanks to our many icy roads a salt known as Calcium Magnesium acetate was developed. Not only is this type of deicer more environmentally friendly it is also biodegradable, non corrosive and less damaging to stone, terrazzo and masonry surfaces.  The down side you might guess is the expense. But what will that new floor cost?

Safe for Concrete Deicers

The biggest concern with deicers is the corrosion of rebar in concrete. For this reason many deicers are claiming to be safe for concrete. This is true as far as less corrosion. Your concern is not necessarily corrosion but salt crystallization. Make sure to check the ingredient of these so called safer deicers by requesting a Material Safety Data Sheet (MSDS) or consult with a stone expert.

  As I travel in areas where deicer are used I see thousands of schools, government buildings as well as public building with damage to stone, terrazzo and masonry flooring.  If the damage is caught in time a restoration company may be able to repair the damage. If these harmful salts continue to be used you’ll be replacing the flooring in a very short time.

 

 

            

Resined slabs: The Good, The Bad and The Ugly

Resined slabs: The Good, The Bad and The Ugly

by Frederick M. Hueston,

Q: Our shop has been getting a lot of resined slabs lately, and I am a little confused as to why slabs are resined to begin with. I would be interested to know why they are resined and what problems fabricators are having with these resined slabs?

A: In the past few years, I have had many fabricators ask the same question. Of all the fabricators I have spoken with, some have no problem at all with resined slabs, while others are having nothing but problems. The following are some of the pros and cons of resined slabs. The following article is not intended to solve this problem or to render an opinion but to put forth arguments from both sides. In other words the good, the bad and the ugly.

The resining of stone slabs is not as new as some might think. Resining started back in the 1960s on marble and about 10 years ago with granite. Today, the resining of slabs is commonplace, and it is predicted that almost all stone slabs will soon be resined.

What is resining?
The resining process uses epoxy resins for granites and polyesters for marble. There are several methods that are used to apply and cure the resin, from hand-spray applications to automated lines. The slabs are first honed and dried, and then the resin is applied. The slabs are then cured in heated ovens, and after the resin is cured, the slabs are sent to the polishing lines where they are polished. Some factories also apply a thin layer of wax to the surface after polishing to help protect the stone during shipping.

The Good
The resining of slabs has allowed slab producers to eliminate lots of waste and sell slabs that would otherwise be rejected. Brittle materials can now be used due to the resining process, which helps hold the brittle material together like a glue.

Resined slabs are also less likely to become damaged during shipping.

Resining of slabs has also reduced the price of slabs, which is one reason the industry is seeing such a big growth in slab sales in recent years.

Resined slabs are also less porous, and many resined materials do not need to be sealed, since the resin acts as a sealer for the stone.

In addition, Filippo Emanuel of Tenax USA listed the following benefits in a recent article in Stone World (June 2003, page 100):

Several materials are naturally fractured and could not otherwise be sold or marketed even if they are superior in terms of color, durability and other qualities.

There is a growing tendency in producing thinner slabs to reduce transportation costs and open up new markets and different stone uses.

The waste from manufacturing slabs of particular materials (especially some marbles) could represent 35 to 40% of production, thus considerably increasing the cost of the remaining slabs.

Many different kinds of granites have natural micro-fissures that compromise the final polished effect, thus reducing the beauty of the material.

There are materials just too fragile to be polished, leaving no solution but to close down quarries.

Some granites have fissures that pass through the slab and considerably decrease the strength of the slabs and pose a hazard when used as outside paneling.

Limited reserves of a particular color of stone leave only the worst and more damaged veins to be quarried.

The Bad and The Ugly
Over the past few years, several problems have arisen with resining slabs. The following are some of the problems that have been encountered:

1. Fading
One of the major complaints associated with some resined slabs is that the resins used are not UV resistant. I have heard of several fabricators who store their slabs outside for several months, and when they go to use them, they discover that the slabs have darkened. This is especially true of slabs that are covered. In one case, a slab of stone was partially covered with another section of stone. When that small section was removed, it was discovered that the portion of the slab that was not covered had darkened. This is the result of UV light reacting with the resin. The lesson to be learned here is not to store slabs outdoors in direct sunlight. This is especially true of light colored materials such as Giallo Veneziano and others.

However, Emanuel points out that there should be no resin on the surface of the slab. “If there is, it means that the manufacturer did not do a good job removing it,” he said. “That is when fabricators start having problems with darkening effects.” If done correctly, the resin is inside the cracks and the pits, but nowhere else.

An additional problem is with profiles. Several fabricators have had experiences with the profiled edge turning out lighter than the rest of the stone. “The problem with the edges is that the resin will darken the top of the slabs regardless of the UV,” Emanuel explained. “It is just the effect of the different reflection of the light when a material is imbibed with resin. When you cut the edge, there is no resin on the side — regardless of the UV exposure. That’s the reason why the edges are lighter.”

Over time, we have found that the edge will darken and match the face of the stone. A quick fix to this problem is to use a color enhancer to darken the edge.

2. Sealer interaction
Our technical hotline has received several calls where impregnators have been applied to a resined stone, and the material clouds, discolors or fades. After testing several slabs and sealers, I have discovered that some solvent-based impregnators will react with the resin, causing it to break down and turn color, cloud or fade. This is a problem that is difficult to repair. We have found that the application of a color enhancer will sometimes hide this problem. My recommendation would be to use only water-based impregnators on resined slabs.

3. Polishing and refinishing problems
In a recent countertop repair seminar, one of our students brought in a resined section of stone he wanted to try and refinish and polish. We discovered that this material had such a heavy application of resin that when he tried honing the top, the resin became gummy. Once the surface was cut and polished, it was very difficult to match the remaining surface of the stone. As of this writing, I have yet to find a solution to this problem other than to refinish and polish the entire slab so it all has the same polish.

Please keep in mind that that some of these problems may be the result of improper application and not necessarily the resin itself. Just like any other industry, quality control can be an issue, and sometimes a slab or two may slip by. This is why it is important to deal with reputable slab distributors and to carefully inspect each slab upon delivery.

Only time and history will tell if the resining process is good, bad or ugly. Of course, resin chemistry will most likely improve, as well as the application process. In the meantime, stone fabricators should be aware of these problems and learn to deal with them.

MOISTURE-STONE ENEMY NUMBER ONE

           MOISTURE-STONE ENEMY NUMBER ONE

 

Most of the problems associated with stone tile installation can be traced to moisture or water intrusion of some kind. Many stains are caused by the presents of water. Water is an essential ingredient for the setting cleaning and restoration of stone but it can also be its number one enemy.

 What problems are associated with moisture and water.  The following is a brief description of the problems, there prevention and remedies:

 

 Efflorescence

 Efflorescence appears as a white powdery residue on the surface of the stone.  It is a common condition on new stone installations or when the stone is exposed to a large quantity of water, such as flooding.  This powder is a mineral salt from the setting bed.  To remove efflorescence do not use water, buff the stone with a clean polishing pad or #0000 steel wool pad.  The stone will continue to effloresce until it is completely dry.  This drying process can take several days to as long as one year.

 Subflorescene

Subflorescene is what happens when the mineral salts migrate and do not make it all the way to the surface. In the efflorescence condition above, the slats are deposited on the surface of the stone. In subflorescene the salts crystallize just below the surface, causing stress within the pores of the stone. The result is a condition known as spalling which appears as pits in the surface of the stone.  subflorescence is very common on green marbles and is very common on almost all stone surfaces where de-icing salts are used.

Iron Staining

 Many light colored stone contain naturally occurring deposits of iron.  Iron is a mineral  found in stone and can occur randomly throughout the stone.  If iron is present, it will begin to oxidize when exposed to water or other oxidizers such as acids and household bleach.  Stone can remain  for years without yellowing then over time may slowly turn yellow and in severe causes may turn completely brown.  This oxidation process is accelerated when the stone is saturated with water.  This process of oxidation is similar to the rusting of metal.  If you expose a brand new nail to water and air it will turn brown and rust.  The same process is occurring with the iron in the stone. If water and/ or air is eliminated the iron will not oxidize.  This is the reason certain white marble suddenly turn yellow.   The process is difficult to reverse and replacement of the stone may be necessary.  The following stain removal technique has proved successful in several cases.  Before testing this procedure it is important to first determine if iron is the cause.

  Testing for Iron:

1.  Before assuming the marble is yellowed due to iron be sure to attempt cleaning and stripping with a good alkaline based stripper.  If these procedures fail then testing for iron will be necessary.

 2.  If a flood has occurred or excessive water was used first check the water for iron.  There are several inexpensive test kits available that can be used to check the iron content in water.  Check with your local plumbing supply store or store carrying water softening supplies.  If any amount of iron is detected then it is possible iron has entered the stone through the water supply.  To eliminate the iron there are chelating chemicals that can be added to the water to prevent the iron from staining.  This is very important if the stone is cleaned with this water.

 3.  If the water contains no iron and even if it does the stone should be checked for iron content.  Remove a small sample of the stone  and contact a testing lab and have them analyzed it for total iron.  If there are spare tiles that have never been installed also have them tested for total iron.  If iron is present naturally in this stone, it will probably be detected in the spare tile.    If the results return with iron present then the following procedure should be tested.

 4.  Check the stone for moisture.  A moisture meter is a useful instrument that can be employed to check the stone for moisture.  If the stone contains water, it is very possible that iron is beginning to oxidize.

 Removing Iron Staining:

 1.  Prepare a solution of water and the following chemical: Sodium Hydro sulfite and Sodium Metabisulfite.  These chemicals are available in a product called Iron-Out(TM) from your plumbing supply or home center.  Mix a solution in water and apply to the effected area.  Allow solution to soak in and keep wet for several hours. Do not allow solution to dry.  After several hours pick up excess solution with a wet vacuum and rinse throughly with water and a chelating agent such as EDTA.  Be prepared to repolish any marble since these chemicals can cause etching.

 2.  If the above procedure fails than prepare a poultice with diatomaceous earth and the Iron Out(TM).  Mix the poultice into a thick paste and apply to a small area.  Cover the poultice with plastic and allow it to sit covered for 24 hours.  After 24 hours remove the poultice paste and rinse the area with water and a chelating agent.  If the stain is removed, the entire surface can be treated. If the stain still remains then replacement is the only solution.

 Before the above procedure can be performed, it is important that the effected area be dry.  If water or moisture are still present, oxidation of iron may continue

 The yellowing of stone is a common problem.  New installations should be sealed with a good quality penetrating sealer(impregnator) Which will help prevent oxidation of the iron by eliminating moisture.

 The above procedure has proven successful in some cases of iron staining however if the following test does not produce the desired results I would recommend replacement of the effected areas.

  Warping

 several type of thin stone tiles are very susceptible to warping. Many of the green marbles and a few agglomerate marbles are notorious for this warping condition.  Many of an installer have had the surprise to find that there tile installation has become warped overnight. Why does this a happen and can it be prevented.  Warping is caused by water. Green marble set with any water based material will have a tendency to warp.  The mechanism of why the tile warps is somewhat a mystery.  Some believe that the water fills the pores of the stone and when the water evaporates the orientation of the stones crystal change and cause it to warp.  Whatever the reason, one thing is for sure, green marble can warp when set with water based materials.

 Cure: Once a green marble tile warps it is difficult to repair. Attempts have been made to grind the tile flat , but this usually fails since additional water is introduced during the grinding process. The green simply warps again.

 Prevention; The only way to prevent warping is to install it properly with a non-water based material such as epoxy. Some installers have also ben successful in sealing the back of the tile with epoxy and installing it in a water based system(see July Stone & tile Report).  Do not attempt to seal the back of the tile with a silicone sealer.  The silicone acts as a water repellant and will cause the setting material to fail resulting in a bond loss.

 Erosion

 Erosion is a condition found when stone is exposed to constant amounts of water. This is especially true with marble that is used in water fountains.  While marble is a very decorative material, it is one of the worst materials to use in or around water.  Marble is composed of calcium carbonate. Calcium carbonate is a water soluble mineral. Quite simply this means it will dissolve in water. Want proof, visit the Grand Canyon.  Erosion can be recognized by a slow deterioration of the stone surface. With polished stone the polish will be worn off. In older installations, the stone may become very soft, brittle and in extreme conditions, it will powder.

If any architects or designers are reading this article I beg you no to use marble for water fountains.  If you do, plan on very high maintenance costs and plan on replacement in about five to ten years if not sooner.

 Stabilizing erosion:

 If your faced with trying to stabilize a marble fountain that is already deteriorated there are some treatment that can be applied that will extend the life of the marble. These treatments are general called consolidants and serve to replace the natural binders that are lost through erosion. Consolidants can be tricky and quite often will cause discoloration of the surface. Be sure to test the consolidant carefully before use.

 Mineral crusts or Lime Putty

 Mineral crusts or lime putty can be recognized by its white crust like formation on stone surfaces. These crusts are often found on outdoor stone stair, water fountains and other areas where stone is exposed to water. The crusts are a deposit of hard mineral salts consisting of calcium, magnesium. These minerals ordinate form the soil, setting bed or from the water itself. These salts are similar to efflorescence in that they are a mineral. They differ in that they form a hard crust that can be difficult to remove.

 Crust Removal

 there are only two ways to remove these mineral crusts. Abrasion or chemical.  The mineral salts should be remove with an abrasive. I have found that a stiff non-ferrous wire brush can work well.  Brushes can also be purchased that attach to an electric drill. Be careful and do not get to aggressive. Avoid damaging the stone surface.

Quite often abrasion alone will not remove all salt deposited. Strong Acidic chemicals will be required. These chemicals can be purchased from most chemical companies that supply stone cleaning products.  Be careful when using these products around calcium based stone since the acid can also damage the stone itself.

 Prevention.

 The best prevention from mineral salts is to prevent moisture form entering the stone.  On steps and fountains make sure all grout joints are caulked with a water proof material. When installing steps outdoors make sure a water proofing barrier is used. It is also a good idea to use a good stone impregnator on all surfaces to prevent water from entering the stone.  Caution; Stone inpregnators will not waterproof stone. Do Not use them where hydrostatic pressure is a concern.

 TESTING FOR MOISTURE

 To properly test for moisture a protimeter is necessary. A protimeter is an instrument that reads moisture. The common protimeter has been designed for use with wood, drywall and other similar substances.  The protimeter contains two sharp probes that are inserted into the wood or drywall to give a direct moisture reading in percent.  Unfortunilty you can not push these probes into the stone, but the protimeter can give you important data oon stone moisture.  By placing the pins so that the just touch the stone a relative reading can be obtained.  For example, A reading of 0-6% is considerely relativly dry. A reading between 7-20% is wet. A reading of of 20% is very wet.  These readings only tell you that the stone is wet, a little wet or dry. A direct percent reading can not be obtain with these instruments, but can provide useful information.

 Another simple technique for determining moisture in stone is to take a piece of plastic about 12 inches square and place it on the suspected stone. Tape all four edges and allow it to stay overnight or 12 hours.  After 12 hours, if there is any moisture present , you will see condensation collecting under the plastic.

 TESTING FOR SALT

 A protimeter can also be used to check for the presents of soluble salts.  The following procedure will only tell you that salts are present. It will not tell you how much or what type. But in many cases the simple presents of salts can indicate potential spalling and/or pitting.

 For this test you will need the following materials:

 

A rubber block

filter paper

distilled water

a protimeter

forceps

 

Any type of rubber will do as long as it is clean and does not contain any salts. A piece of hard plastic can also be used.  Filter paper can be purchased from a scientific supply store and sometimes from the supplier who sells protimeters.  Distilled water can be purchased from the grocery store.

The forceps are used to pick up the filter paper.

To check for soluble salts pick up a filter paper with the forceps. DO NOT touch the filter paper with your fingers. The human skin contains soluble salts which could be transferred to the paper giving a false reading.  Place the filter paper on the rubber block. Add a drop of two of distilled water to the filter paper. Place the probes of the protimeter to the filter paper and record the reading.  Next, take a new filter paper and place it on the stone to be tested. Add several drops of distilled water and take a reading. Record the reading on a piece of paper.

 If the reading obtained on the filter paper from the stone is higher, then there are slats present. If it is the same or lower, salts are absent.  The protimeter works by reading ionic changes. When salts are dissolved in water, the ionic changes are higher, which gives a higher reading.

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