White Film and Sealer Build Up on Slate Tiles

March 8, 2013 Off By Torin Dixon

sealer build up on slate tilesRemoving old Sealers on Slate Tiles
By Torin Dixon

I had a customer call this week complaining about several problems with her Slate Tile floor and shower.

She described how after about seven years, by the hands of different contractors and handymen, there were many layers of sealer on her slate. She described it as being blotchy, and some areas were shiny where the sealer was on the surface, and other areas where the sealer has turned white or creamy especially in her shower. The attached images in this post are her slate. (look forward to final images when she is finished)

These descriptions indicated that there were many layers of different types of sealer, and to get it back in shape the sealers (all of them) would have to be stripped off. She wanted to tackle the project herself, so this is what I prescribed:

Items needed:

  • HMK R54 Stripper Stain Remover (1-liter per 50-80 square feet of area)
  • HMK R55 Intensive Cleaner (1 liter diluted will cover approximately 400 square feet)
  • 1-2 gallon bucket or pail (for mixing R55)
  • Roll of paper towels
  • Rubber Gloves
  • Disposable paint brush or Sealer Applicator Brush
  • 2 Scrub Brushes (one for stripper, one for cleaner)
  • 2 Sponges (tile grout sponges work well)
  • 2 Five gallon buckets with warm rinse water


      1. Apply HMK R54 Stripper-Stain Remover to a manageable area (3′ x 5′) using a paint brush. Allow to dwell on surface (wet) for 15 minutes.
      2. While R54 is dwelling, mix a solution of 1-part R55 with 4-parts warm water in small pail.
      3. Using 1st scrub brush, scrub area vigorously where you applied the R54 stripper. (keep 1 scrub brush for stripper only)
      4. Wipe up stripper quickly with paper towels. Do not allow to dry.
      5. Immediately dip sponge into R55 solution and squeeze out solution and apply to area. Using 2nd scrub brush, vigorously scrub area where you applied sealer. Allow to dwell on area for 5-10 minutes. Scrub area again, and wipe up excess solution with 1st sponge and rinse in first water bucket.
      6. Keep second sponge and bucket separate and use ONLY for final rinse. (R55 solution is very concentrated and sudsy)
      7. Using 2nd bucket of rinse water. Rinse area thoroughly two times. Refresh rinse water often.
      8. Move on to next area and repeat process until all areas are covered.
      9. Allow to dry.
      10. Observe areas to see if a second application is necessary to completely remove old sealers. Repeat as necessary.

Once you are satisfied that area is clean and raw (back to new) you will want to apply some type of Sealer or Impregnator. For a complete discourse on which type of Stone Protection to choose, please review a previous post HERE


Below is a picture of the shower walls showing a white – creamy film. This is often caused by moisture reacting with topical acrylic sealers causing hazing.

Slate tiles need to be stripped to remove excess old sealers and white haze filmFor shower areas, use the same procedure (above) to clean shower walls. (click image for larger view)



If you have any questions or comments about Removing Old Sealers from Natural Stone, please contact us at 800-380-6881 or email: info@stonecareonline.com