Slate Tile Floor Care

Slate flooring

Slate, a very dense but soft and easily scratched material with low porosity, can be used effectively outdoors as well as indoors. Higher absorbency varieties are not suitable for exterior areas in freezing climates. Slate is a fine grained metamorphic rock formed by the metamorphism of shale and clay under lower pressures and temperatures which tends to split into sheet-like (cleavage planes) structures formed in response to differential stress. It comes in a multitude of colors and has two lines of breakability (cleavage & grain).

Composition: Mainly grains of mica and quartz, plus smaller amounts of chlorite, hematite, and other minerals. Most slate is gray to black, but the rock may be red or purple, depending on its mineral content. The surface of slate is generally uneven and cleft planes can spall, due to the cleaving of the stone along its layers. Has low to medium absorption of oils and other liquids. Should be sealed with an oil-repellant penetrating sealer to prevent staining and reduce soiling. Because of the cleft planes and strong possiblility of spalling, it should never be cleaned at pressures above 800 PSI and then only if the grout is in good condition.

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. This is not rust or other minerals coming to the surface. These are spots of softer material becoming loose particles. Some slates may be quite hard, but have a soft spot that can powder out. Some black and brown slates (if unsealed) can lose color from aggressive cleaning.

StoneTech™ Professional BulletProof™ is recommended for any slate that tests for sufficient absorbency. (Test slate with water drops. This is a water based sealer that must all penetrate. Therefore, the slate must be able to absorb a water drop in 3 seconds. If the slate is not sufficiently absorbent, use Impregnator Pro™.

Slate is very stain resistant. However, some foods can cause stains. EnhancerPro™ 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. High Gloss Stone Sealer can also be used where a glossy finish is desired (interior only).

Slate has a hardness of 6 on the MOH Scale (a scale for determining the relative hardness of a mineral according to its resistance to scratching). The hardest mineral, at 10, is diamond. The softest mineral, at 1, is talc.

What are the DO's and DON'Ts of Slate?

  • 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™ Professional Revitalizer™ Cleaner & Protector.
  • DON'T wait to clean up spills on stone.
  • 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 alkaline cleaners not specifically formulated for stone.
  • DON'T use scouring powders and abrasives because they will scratch the surface.
  • DON'T clean at high pressures.

Cleaning Instructions for Slate:

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

  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™ Professional™ KlenzAll™ 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 scrub brush, stiff bristle push broom or a weighted floor machine at 110 lbs.-140 lbs., 175 rpm, fitted with a scrub brush attachment. Some softer slate may not require as much weight on the floor machine, up to 90-110 lbs. may be sufficient. Test first, in an inconspicuous area, to insure 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 insure 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 Professional™ Oil Stain Remover:
    1. Apply a ¼ inch thick coat of Oil Stain Remover to the oil stained area. Insure that Oil Stain Remover covers an area 1” to 2” 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):

  1. Test in an inconspicuous area, as some materials are acid sensitive and may etch when acidic cleaners like StoneTech Professional™ 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 weighted floor machine at 110 lbs.-140 lbs., 175 rpm, fitted with a scrub brush attachment. Some softer slate may not require as much weight on the floor machine, up to 90-110 lbs. may be sufficient. Test first, in an inconspicuous area, to insure 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 insure that all dirt, soil and cleaner residue have been removed. Thoroughly rinse all metal surfaces.

Sealing & Protecting Slate Tile:

Natural stone surfaces must be sealed to prevent or minimize staining. Leaving natural stone untreated may greatly hinder the complete removal of stains in the future. The following suggestions are for impregnating 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 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. Insure that surface is clean and residue-free.
  4. StoneTech Professional™ Stone Sealer or BulletProof™ 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 insure 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 surfaces (heavy duty protection, water repellency only) on slate:

  1. StoneTech Professional™ Heavy Duty Exterior Stone and 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. Insure 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 insure 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. Insure that surface is clean, dry and residue-free.
  4. Liberally apply an even coat of StoneTech Professional™ Enhancer Pro™ using a low-pressure solvent-resistant sprayer, roller or brush.
  5. Allow to 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 insure 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, natural look, topical protector on interior surfaces only, use new water-based High Gloss Lacquer. Follow label directions.:

  1. Not for exterior use.
  2. Thoroughly pre-clean all debris, dirt, oil, grease and general stains from the surface using KlenzAll™.
  3. Remove waxes, coatings and paints first with Heavy Duty Coating Stripper.
  4. Allow newly cleaned surface to completely dry prior to applying StoneTech Professional™ High Gloss Stone Sealer.
  5. Mask off and protect any baseboards or adjacent areas to avoid splashing and overspray onto surfaces not intended to be treated.
  6. Apply in air temperatures between 55°F to 80°F and on a cool dry surface.
  7. 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.
  8. Allow 1-3 hours between coats or until surface is completely dry to the touch.
  9. 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.
  10. Keep surface clean and dry as finished surfaces may become slippery when wet.
  11. 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.
  12. 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 StoneTech Professional™ 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 Professional™ All Purpose Stone and 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.

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

Additonal Information on Stone Care:

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