ON SLATE

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ON SLATE

By Gabriele Campbell, ASP, CID            www.campbellinteriordecorating.ca

Ask me what type of flooring belongs in the foyer, my answer will usually be slate. The intrinsic durability and rough texture of slate make it a natural for this area.

It’s not just for foyers anymore – we are using slate in kitchens, mud rooms, laundry rooms and bathrooms. It surrounds the fireplace, plays backstop on the backsplash and, in luxury spaces, has become a floor to ceiling treatment in favour of paint.

Slate is formed by the metamorphosis of shale, clay and volcanic ash, and combines with minerals and plant, animal and insect life to give it that unique blend of texture, colour and depth. The minerals found in slate include quartz, mica, chlorite, hematite  muscovite, illite, biotite, pyrite along with, less frequently, apatite, graphite, kaolin, magnetite, tourmaline, or zircon.

Slate comes from quarries in Newfoundland, the United States, India, China, Wales, Africa, Brazil, Portugal and Italy.

When selecting slate there are some features to keep in mind. There are five styles of slate:

1. Gauged – ¼” thick, consistent colour and smoother cleft; easiest to install
2. Semi-gauged – 3/8” thick, cleft surface. The back is mechanically ground to a flat finish for less variation in thickness for easier installation
3. Ungauged – 3/8” – 5/8” thick. Both sides of the stone have a cleft finish, and is therefore more difficult to install and more expensive
4. Random – extreme variations in thickness, size and shape; difficult to install
5. Slab – 1 1/8”  thick, used mostly for countertops

The finishing options of slate include natural cleft, honed and polished, each referring to the surface smoothness.

Because slate is naturally formed, each tile has a unique “finger print” and no two ever look alike. Installation of slate is more expensive as it requires more thin set and grout, and the installer must offer an experienced “artist’s” eye to create a pleasing composition in the placement of tiles.

Slate is a heavy stone and appropriate consideration should be made for the sub-floor plywood. If being installed over old concrete, expansion joints should be used in any cracks prior to installation.

Depending on the sealant used, the floor will have to be sealed regularly.

• Natural penetrating – leaves stone non-slip, does not change the look of the slate
• Enhanced penetrating – leaves stone non-slip, will darken and hi-light the colours in the stone
• Surface sealer – makes stone appear wet, enhancing the colours, but can compromise the slate’s non-slip properties; shows scratches more than other sealers

The supplier/installer will recommend the appropriate cleaner to use on slate as commercial products can be too abrasive on the delicate chemical balance of natural stone.

This beautiful, durable product is also non-slip and non-allergenic. When selecting your flooring, three factors play the biggest role: performance, maintenance and budget. What do you want it to do, what are you willing to do to maintain it, and how much can you spend? If slate fits your criteria, it’s a finish you will enjoy for decades.