Installing Slate Floors

Slate flooring is known for its character nearly indestructible physical properties. Once sealed, its micro-crystalline composition makes it very stain resistant. Slate flooring is a popular choice in kitchens, patio areas and in bathrooms. Installing slate floors takes a little time and effort but the end result is a truly unique floor that will last for years with very little maintenance.

In this article we will walk you through some of the basics of installing a slate floor so that you can decide if this is a do-it-yourself project that would like to tackle.

Tools Required

Lets talk about what tools you will need to do the installation of slate floors first. You will need a chalk line, a tape measure, a framing square, a special square-notched trowel, a large sponge, knee pads, buckets, a three-inch wide stiff blade scraper, a grout float and most importantly a diamond-blade wet saw.

The diamond-blade wet saw can be rented from most home improvement centers. While you can substitute an old circular saw for the diamond-blade it is highly recommended for ease of installing the slate floor to use a wet-blade saw.


Slate flooring can be installed on a wood sub-floor if the wood flooring is at least one and one quarter inches thick. If your sub-floor does not meet this you can install half-inch plywood over the existing sub-floor to bring it up to the minimum height and applying a thin coat of water-based urethane to the final layer of plywood.

The urethane prevents water from soaking into the unprotected plywood. A better option is to install one-half inch thick cement board, but supplies of cement board are not readily available in many parts of the country.


The layout of slate is very important when installing a slate floor. Although most slate floors can appear to be a mosaic of random pieces, they are in reality different-sized pieces that carefully interlock in a very regular repeating pattern. The pattern is usually printed on the carton or included in a piece of paper.

You will need to remove the slate from just one of the cartons at a time and lay it on the floor carefully spacing to create the pattern recommended by the manufacturer.


After the slate has been installed using a thinset to bond with the sub-floor the next step is to grout and seal it. The grouting process is extremely important for proper installation of the slate floor. The grout must be the consistency of cake batter, too thin and it will not bond properly and too thick and you will have a real mess on your hands and be unable to properly smooth it out between the tiles.

Excess water must be removed as you put down the grout as this is the leading cause of cracking. You must get all traces of grout from the slate before the grout dries, so have a sponge ready and work slowly.

As you can see installing slate flooring can be a time consuming and meticulous process, but the end result is a floor that is as unique as you are. This is an ideal project for the do-it-yourselfer who has tackled easy projects and is now ready to move on to the next level.

See Also:

Slate Flooring Tile
Brazilian Slate Countertop