The Care of Slate Floors

Because "Natural Slate" is practically immune to all common chemicals, it is probably the least exacting of floors in the matter of maintenance. Any of the usual cleaners may be used on slate with safety, though strong alkaline solutions or acids may affect the grout joint. Being dense and practically non-porous, slate is not affected by strong detergents or ammonia.

Synthetic Detergents

To maintain a slate floor, it should be kept clean like any other floor, scrubbing as necessary and mopping between times. To scrub a cleft floor, use a strong solution of floor detergent. Spread it over the surface and let it stand for several minutes. Then, with fresh solution, scrub with a stiff brush under a floor machine. Abrasive powders are less desirable as they sometimes leave residue. After the slate has been thoroughly cleaned, rinsed and allowed to completely dry, it will benefit from the application of a protective treatment. The word "protective" is not to imply that the slate needs protection, but that a coat of wax, sealer or impregnator will allow it to be cleaned easier in the future.

Sealers / Impregnators

Slate, supplied in the standard "natural cleft" finish may be sealed or have an impregnator applied. The sealer best adapted for slate should be of low viscosity and less than 25% in solids. The new impregnators also work very well, however, any treatment should be applied strictly in accordance with the manufacturer's recommendations. Impregnators usually do not create a gloss finish, whereas sealers may be a gloss or satin finish. Care should be taken to assure that the slate as well as the grout joints are totally dry and the floor clean prior to application. Dampness in the joints can cause treatments to turn white. Most all sealers and impregnators are a permanent treatment and are very difficult to remove. A sample piece or small area should be treated first to assure that this is the desired end finish.



The water waxes and resin finishes will serve better on interior surfaces since they seldom hold up satisfactorily on outdoor surfaces. Sometimes they turn gray from exposure and are difficult to remove. The solvent waxes are less affected by the exposure, but since they must be buffed when dry, they present a problem on a natural cleft surface rather than a smooth surface. For interior slate, either kind of wax will emphasize the colors and make sweeping and dusting much easier.

Dust and ordinary soil will adhere less tenaciously to a waxed surface and often dry buffing will avoid the need for mopping or scrubbing. If soil on the waxed surface resists buffing with a brush, fine steel wool or an abrading pad may be used. Care should be taken not to dig into the wax if possible. Some of the acrylic waxes are very good on natural slate. For interior slate, any of the self polishing water waxes or one of the emulsified resin finishes may be best suited as they do not require buffing after drying.

Traffic Patterns

Most heavy use areas will eventually develop "traffic patterns". It may appear that the slate is wearing, but more often than not it is the finish. Waxes can be stripped and reapplied, however some sealers are relatively permanent. A record of the finish and manufacturer should be kept as some sealers are not compatible with others. The original manufacturer may be contacted for recommendations for re-sealing or removal of the finish.

Slip Resistance

Care should be taken when applying any finish to slate as well as any stone to preserve "slip resistance" on commercial projects. A stone's slip resistance can be greatly altered by the application of any finish. While this is extremely important on commercial floors, it is also desirable in the home. All floors are slippery when wet and the use of some finishes may compound the problem.

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  • Physical Properties
  • Interior Flooring
  • Applied Finishes
  • Installation Details
  • Exterior Paving
  • Basic Specification
  • Panels
  • Anchors, Dowels, Etc.
  • Window Stools
  • Floor Care
  • Copings
  • Window Sills
  • Treads & Risers
  • Counter Tops

  • The Structural Slate Company
    222 East Main Street
    P.O Box 187
    Pen Argyl, Pennsylvania 18072-01
    1.800.67.SLATE or Fax: 610-863-7016