How can I give my black slate a wet or polished look?
Estimated Reading Time: 2 MinutesQ. Our house was built in 1967 and has black slate flooring inside and on the porch and terrace. We've had some restoration work done, but we're not happy with how it looks. Even after sealing, it doesn't have the polished or wet look we were hoping for. What products or methods can we use to get that finish?
A. Slate is a beautiful and durable natural stone. We understand that you have certain expectations about how your stone should look after restoration. Here's the thing about slate: it doesn’t naturally polish to a mirror-like finish like marble or granite because of its layered, textured structure. Its cleft surface resists high-gloss polishing.
That said, skilled professionals can sometimes achieve a semi-gloss or satin sheen through honing and polishing, but a true mirror-like shine is generally not possible or practical on slate. If you want that glassy, reflective finish, other stones like marble or granite might be better suited. For slate, enhancing its natural texture and color with the right sealers is usually the best approach.
To make the stone look wet, apply color-enhancing sealers. They will soak into the stone and bring out the deep, rich colors in the stone. Note that your stone may have a wet appearance after color-enhancing sealers are applied, but it will not likely be shiny or reflective.
To give the stone a polished or reflective finish, use solvent-based polyurethane or acrylic sealers. Note that these sealers are durable indoors but have strong odors and may yellow or peel outdoors. Water-based urethane sealers are a great alternative because they offer a low-odor, more natural-looking finish with less yellowing risk. Note that these sealers produce a subtler sheen and less gloss.
Regardless of which sealer you choose, follow the manufacturer's instructions for proper surface preparation and application.
While we’ve provided guidance to help answer your question, achieving the best results often requires professional expertise and a combination of sealers. We recommend consulting a specialist to ensure the work is done correctly and the best possible results are achieved.
To find a vetted PRO in your area, visit www.surfacecarepros.com and click on Find a PRO. They can inspect your slate and recommend the best method and product based on your goals, whether you’re looking for a subtle enhancement or a high-gloss finish. In many cases, a deep cleaning, followed by the application of a premium enhancer or sealer, makes a dramatic difference.
ABOUT THE AUTHOR Fred Hueston is the Chief Technical Director at SurfaceCarePROS.com and Director at StoneForensics.com. He is also the author of Stone and Tile Restoration: The Manual, a comprehensive online manual for stone and tile restoration contractors. [Learn more about Fred.]