Wednesday, August 07, 2019

SLATE - Properties, Advantages, Disadvantages, Sealing, Do’s and Don’ts in Maintenance, Cleaning, Color Enhancing, Shining



Slate flooring image

How to Clean, Seal and Maintain Slate Tile Floors




Slate must be sealed to prevent or minimize staining. Leaving slate untreated will prevent complete removal of stains.

Properties of Slate Stone Tile:

  • Composition of slate: Mainly grains of mica and quartz, plus smaller amounts of chlorite, hematite and other minerals.
  • Slate is a fine grained metamorphic rock formed by the metamorphism of shale and clay under lower pressures and temperatures.
  • Formed from clays, slate is layered and compressed at the bottom of lakes.
  • Slate stone is a very dense, soft, easily scratched natural stone.
  • Unlike marble and limestone, slate is not sensitive to acids.
  • Most slate is gray to black, but the rock may be red or purple, depending on its mineral content.
  • Vermont type slate is typically smoother, denser, one color (red, green, black, blue).
  • Indian and Chinese slates are dense and soft, of all colors and variegated colors.
  • Brazilian slate is typically dense and hard, interesting colors and patterns of color.
  • Some Indian and Chinese slates will flake and powder from foot traffic.

Advantages of Slate Tile:

  • Slate creates a very natural and beautiful finish to any wall or floor.
  • Slate is very stain resistant except to some foods.
  • which tends to split into sheet-like (cleavage planes) structures formed in response to differential stress.

Disadvantages and Shortcomings of Slate Tile:

  • Slate has two lines of breakability - cleavage & grain.
  • Slate has a hardness of 6 on the MOH Scale, making it easily scratched. The hardest mineral, at 10, is diamond. The softest mineral, at 1, is talc.
  • Some black and brown slates (if unsealed) can lose color from aggressive cleaning.
  • Often containing iron, the red coloration seen in some slate is from the rusting of the iron. This will continue to worsen if not treated with a high quality, long lasting water repellant.
  • Slate has low to medium absorption of oils and other liquids and should be sealed with an oil-repellant penetrating sealer to prevent staining and reduce soiling.
  • The surface of slate is generally uneven and cleft planes can spall, due to the cleaving of the stone along its layers.

  • Slate flooring image
    Slate flooring image
  • The cleft surface, exposed when the layers of slate are separated, will easily collect grout at installation and trap dirt with improper maintenance.
  • Because of the cleft planes and strong possibility of spalling, it should never be cleaned at pressures above 800 PSI and then only if the grout is in good condition.
  • Some slates may be quite hard, but have a soft spot that can powder out.
  • For the first three months after installation, some small pieces may flake or break off of the tiles. This is called “spalling,” and is a natural process that occurs as the slate gets used to the new environment.

Where Slate Can be Used:

  • Slate can be used in fireplace surrounds, floors, countertops, backsplashes, showers, mudrooms and exterior walkways.
  • Slate can be used effectively outdoors as well as indoors.
  • Higher absorbency varieties are not suitable for exterior areas in freezing climates.

What Sealers Can be Used to Protect Slate Against Stains?:

  • Some of these slates are porous and will absorb moisture, and these slates may also absorb stains. Therefore, it is important to seal your slate on a yearly basis to prevent staining. Test your slate to see if it is porous by pouring water on its surface. If the water leaves a dark area after 10 minutes, your slate needs to be sealed. If the stone does not change color, it does not require sealing.
  • StoneTech™ Bullet Proof™ water-based stone sealer is recommended for any absorbent slate.
  • (Test slate with water drops. Bullet Proof is a water based sealer that must be able penetrate the stone to seal properly. Therefore, the slate must be able to absorb a water drop in 3 seconds. If the slate is not sufficiently absorbent, use solvent-based Impregnator Pro™ or Sta-Clene®.
  • Enhancer Pro™ gives slate a beautiful ‘wet’ look that does not cause a glossy built up finish. Many people make the mistake of applying heavy waxes or floor finishes that rob the slate of its natural beauty and slip resistance. NEVER use enhancing sealers or topical sealers in a shower stall!
  • High Gloss Finishing Sealer for Stone can also be used where a glossy finish is desired (interior only).

What are the DO’s and DON’Ts of Slate Tile Care?

  • DO use rugs or mats to protect floor from heavy foot traffic because slate scratches easily.
  • DO use felt pads on chair legs to avoid scratching.
  • DO carry furniture when moving across the room, instead of sliding
  • DO apply sealer once a year
  • DO clean up spills immediately to minimize damage to your stone.
  • DO use trivets or mats under hot dishes and cookware.
  • DO use place mats under china, ceramics, silver and other objects that can scratch your stone’s surface.
  • DO use coasters under glasses, especially if they contain alcohol or citrus juices.
  • DO clean surfaces regularly with StoneTech Revitalizer™ Cleaner & Protector.
  • DON’T wait to clean up spills.
  • DON’T use cleaners that contain acid such as bathroom cleaners, grout cleaners or tub cleaners.
  • DON’T use vinegar, bleach, ammonia or other general-purpose cleaners.
  • DON’T use abrasive cleaners such as dry cleansers or soft cleansers.
  • DON’T use a product containing vinegar, lemon or bleach
  • DON’T use cleaners not specifically formulated for stone.
  • DON’T use scouring powders and abrasives because they will scratch the surface.
  • DON’T move furniture across the floor without a protector underneath.
  • DON’T use a vacuum cleaner that has a beater bar.
  • DON’T clean at high pressures.

How to Properly Clean Slate:

For cleaning of grease, oil, dirt, dry soil and soap scum on slate:

  1. Mask off and protect any baseboards or adjacent areas to avoid splashing and overspray onto surfaces not intended to be treated.
  2. Sweep or dust mop loose dirt and debris.
  3. Strip off all topical finishes such as waxes and coatings.
  4. Prepare a solution of StoneTech Klenz-All™ mixed with warm or hot water as suggested below:
  5. Medium Duty Usage - Mix 1 part KlenzAll to 4 parts of water.
  6. Heavy Duty Usage - Mix 1 part KlenzAll to 2 parts of water.
  7. Apply KlenzAll using a low-pressure chemical-resistant sprayer, sponge or mop.
  8. Agitate well using a stiff nylon bristle Grout Line Pivoting Brush, stiff bristle push broom or a weighted buffer at 110 lbs.-140 lbs., 175 rpm, fitted with a scrub brush attachment. Test first, in an inconspicuous area, to ensure that the slate surface is not being damaged.
  9. Rinse well with clean water and mop, sponge or wet vacuum to remove the remaining cleaning solution. A hard surface extraction wand and portable or truck mounted extraction machine may be used.
  10. Repeat the rinsing and wet vacuum process to ensure that all dirt, soil and cleaner residue have been removed.
  11. To remove deep or stubborn oil stains not completely removed by KlenzAll, let the surface dry and use StoneTech Oil Stain Remover:
    1. Apply a ¼ inch thick coat of Oil Stain Remover to the oil stained area. Ensure that Oil Stain Remover covers an area 1 inch to 2 inches beyond the stained area for the purpose of containment.
    2. Allow 2-3 days for the Oil Stain Remover to dry to a powder.
    3. Sweep and wipe up dried powder and evaluate the stained area for removal.
    4. Repeat process if needed.
    5. Remove any remaining Oil Stain Remover using mineral spirits.

For removal of efflorescence, grout haze, salts, mineral deposits and all other calcium-based stains (acidic cleaning) from slate:

  1. Test in an inconspicuous area, as some materials are acid sensitive and may etch when acidic cleaners like StoneTech Restore™ are applied.
  2. Mask off and protect any baseboards or adjacent areas to avoid splashing and overspray onto surfaces not intended to be treated. Restore may damage stainless steel and other surfaces.
  3. Sweep or dust mop loose dirt and debris.
  4. Strip off all wax, acrylic, urethane and all topical finishes.
  5. Prepare a solution of Restore™ mixed with warm or hot water as suggested below:
    • Medium Duty Usage - Mix 1 part of Restore to 4 parts of water.
    • Heavy Duty Usage - Mix 1 part of Restore to 1 part of water.
  6. Liberally apply using a low-pressure chemical-resistant sprayer, sponge or mop.
  7. Agitate well using a stiff nylon bristle scrub brush, stiff bristle push broom or a 175 rpm rotary floor machine fitted with a scrub brush attachment. Test first, in an inconspicuous area, to ensure that the slate surface is not being damaged.
  8. Rinse well with clean water and mop, sponge or wet vacuum to remove the remaining solution. A hard surface extraction wand and portable or truck mounted extraction machine may be used.
  9. Repeat the rinsing and wet vacuum process to ensure that all dirt, soil and cleaner residue have been removed. Thoroughly rinse all metal surfaces.

How to Seal & Protect Slate Tile:

Slate stone must be sealed to prevent or minimize staining. Leaving slate untreated may greatly hinder the complete removal of stains in the future. The following suggestions are for sealing the stone and will allow the stone to breathe. Allow new installations to cure for 72 hours prior to applying sealer.

For a natural looking protector on interior and exterior slate (heavy duty protection, water and oil repellency):

  1. Sweep or vacuum all dust, dirt and debris.
  2. Mask off and protect any baseboards or adjacent areas to avoid splashing and overspray onto surfaces not intended to be treated.
  3. Ensure that surface is clean and residue-free.
  4. StoneTech Stone Sealer or Bullet Proof may be applied to damp surfaces one hour after standing water has been removed.
  5. Liberally apply an even coat of sealer using a low-pressure chemical-resistant sprayer, roller or brush.
  6. Allow sealer to penetrate the surface for 20-30 minutes. During this time, distribute excess over entire area to ensure even penetration. Wipe off any remaining sealer prior to drying on the surface.
  7. A second coat may be needed for porous, absorbent surfaces and should be applied 30-40 minutes after initial application as directed above.
  8. A minimum of 30 minutes after final application, wipe entire surface with a towel dampened with sealer to remove any residue and excess sealer, if needed.
  9. A full cure is achieved after 24-72 hours; foot traffic may begin in 6-8 hours. Cover with red rosin paper, if foot traffic must resume before the recommended time periods have passed.
  10. Expected coverage is 600-800 sq. ft. per gallon.
  11. Re-application of Heavy Duty Stone Sealer:
    • A 3-5 year re-application is needed for interior surfaces.
    • A 1-3 year re-application is needed for exterior surfaces.

For a natural looking protector on exterior slate (heavy duty protection, water repellency only):

  1. StoneTech Heavy Duty Exterior Heavy-Duty Stone & Masonry Sealer is a water repellent specially designed for exterior projects such as facades, cladding, pool decks, parking areas and driveways. It is very resistant to chemicals (i.e., chlorine) and to the effects of weather (i.e., ultraviolet light/sunlight, driving water/rain).
  2. Sweep or vacuum all dust, dirt and debris.
  3. Mask off and protect any baseboards or adjacent areas to avoid splashing and overspray onto surfaces not intended to be treated.
  4. Ensure that the surface is clean, dry and residue-free.
  5. Liberally apply an even coat of Heavy Duty Exterior Stone and Masonry Sealer with a brush, paint roller or solvent-resistant low-pressure sprayer.
  6. Allow sealer to penetrate the surface for 15-30 minutes; denser material may require more time for sealer to penetrate. During this time, distribute excess over entire area to ensure even penetration.
  7. Wipe off any remaining sealer prior to drying on the surface.
  8. A second coat may be needed for porous, absorbent surfaces and should be applied one hour after initial application as directed above.
  9. If sealer was not completely wiped off and a residue appears, wipe entire surface with a towel dampened with sealer. Use a white, non-abrasive nylon brush or pad to loosen residue and follow with a clean, white absorbent towel to remove.
  10. Do not walk on surface for at least 4-6 hours. Full cure is achieved in 24-72 hours.
  11. Expected coverage is 600-800 sq. ft. per gallon.
  12. Re-application of Heavy Duty Exterior Stone and Masonry Sealer:
    • A 5-10 year re-application is recommended for exterior surfaces.

For a color enhancing, impregnating (non-topical) protector on interior and exterior surfaces (heavy duty protection, water and oil repellency):

  1. Sweep or vacuum all dust, dirt and debris.
  2. Mask off and protect any baseboards or adjacent areas to avoid splashing and overspray onto surfaces not intended to be treated.
  3. Ensure that surface is clean, dry and residue-free.
  4. Liberally apply an even coat of StoneTech Enhancer Pro™ using a low-pressure solvent-resistant sprayer, roller or brush.
  5. Allow the Enhancer Pro penetrate the surface for 15-30 minutes; denser material may require more time for Enhancer Pro to penetrate.
  6. During this time, distribute excess over entire area to ensure even penetration.
  7. Completely wipe surface dry.
  8. DO NOT ALLOW ENHANCER PRO TO DRY COMPLETELY ON SURFACE! Failure to remove enhancer from the surface may result in a film or residue that may need to be mechanically removed.
  9. A second coat may be needed for porous, absorbent surfaces or if a darker appearance is required and should be applied one hour after initial application as directed above.
  10. A full cure is achieved after 24-72 hours; foot traffic may begin in 6-8 hours.
  11. Cover with red rosin paper, if foot traffic must resume before the recommended time periods have passed.
  12. Expected coverage is 600-800 sq. ft. per gallon.
  13. Re-application of Enhancer Pro:
    • A 3-5 year re-application is needed for interior or exterior surfaces.

For a high gloss, shiny but natural look, topical protector on interior surfaces only, use StoneTech water-based High Gloss Stone Sealer:

  1. Not for exterior use.
  2. Follow label directions.
  3. Thoroughly pre-clean all debris, dirt, oil, grease and general stains from the surface using KlenzAll.
  4. Remove waxes, coatings and paints first with Heavy Duty Coating Stripper.
  5. Allow newly cleaned surface to completely dry prior to applying StoneTech High Gloss Finishing Sealer for Stone.
  6. Mask off and protect any baseboards or adjacent areas to avoid splashing and overspray onto surfaces not intended to be treated.
  7. Apply in air temperatures between 55°F to 80°F and on a cool dry surface.
  8. Liberally apply 2-4 even coats with a natural bristle brush, roller, or paint pad applicator. Do not apply product with a sprayer or sponge. Avoid puddling of liquid during application. Failure to apply a sufficient amount of sealer to the surface may result in an undesirable finish or degradation of the coating. More coats may be applied if desired.
  9. Allow 1-3 hours between coats or until surface is completely dry to the touch.
  10. Surface traffic may begin 12 hours after final application; keep installation dry for a minimum of 12 hours; full cure is achieved in 24-48 hours.
  11. Keep surface clean and dry as finished surfaces may become slippery when wet.
  12. Coverage varies depending on the porosity of the surface, method of application and desired thickness of coating. Approximately 100 to 300 sq. ft. per gallon depending on stone, porosity, texture of surface and method of application.
  13. Re-application of High Gloss Stone Sealer to interior stone:
    • 1-3 years based upon wear.

Maintenance Cleaning of Slate Tile

Highly alkaline, acidic, ammoniated, abrasive cleaners and/or bleach may break down the sealer, adversely affecting repellency and may not be good for the stone. Use a neutral cleaner specially formulated for natural stone.
For routine cleaning with protection (not recommended for lacquered surfaces):
  1. Sweep or dust mop loose dirt and debris.
  2. Prepare a solution of Revitalizer concentrate mixed with warm or hot water as suggested below:
    • Light Duty Usage - 1 part Revitalizer to 4 parts water.
    • Medium Duty Usage/Spray Refill - 1 part Revitalizer to 1 part water.
      (One gallon of concentrate makes up to five gallons of ready-to-use solution.)
  3. Apply the Revitalizer solution using a low-pressure chemical-resistant sprayer, mop, sponge or automatic scrubbing machine.
  4. No rinsing needed.
  5. Or use Revitalizer in a ready-to-use sprayer.
For routine maintenance cleaning:
  1. Sweep or dust mop loose dirt and debris.
  2. Prepare a solution of StoneTech All Purpose Stone & Tile Cleaner concentrate mixed with warm or hot water as suggested below:
    • 2 ounces All Purpose Stone and Tile Cleaner in 1 gallon of water. (Do not mix stronger than 2 ounces to a gallon as a maintenance cleaner. One gallon of concentrate makes 65 gallons of cleaning solution.)
    • Apply the solution using a sponge, mop or automatic scrubbing machine,
      then wipe or rinse off.
    • Or use All Purpose Stone and Tile Cleaner in a ready-to-use sprayer.

Additional Stone, Ceramic and Porcelain Tile & Grout Information:

Products for Cleaning, Polishing, Protecting and Sealing Slate Stone:




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Copyright: Bane-Clene® Corp.

Date Published: August 7, 2019

Date Modified: August 7, 2019



Posted by Bane-Clene® Corp. at 12:05 AM