Installing Slate Tile

Measure

Measure the length and width of the area. You'll need the measurements to purchase the materials, including the slate. Lay out the pattern that you want. When you install slate tile, you need to have an uncoupling underlayment to prevent the slate from cracking. Pressure on a subfloor or substrata creates two different stresses on wood and slate. The uncoupling membrane neutralizes the differences and prevents the slate from breaking loose later.

Prepare the Area

Regardless of the type of material, you lay the slate over, you need to prepare the base. First, make sure the area is level before you go any further on the project. If you find areas that have dips and grooves, put a layer of filler down and then proceed to the next step. Nail down any loose boards or replace them.

Lay the Uncoupling Membrane

Spread a layer of latex Portland cement on the floor and lay the uncoupling membrane onto the area. Since most of the uncoupling membranes come in sheets, don't put down more mortar than you can lay in a 15-minute period. Roll the uncoupling membrane and smooth it in place.

Last-Minute Preparations

Check the any doors to see if you'll have room for the door to open with the tile down. Do this by laying a piece of slate in front of the doorway. There should be adequate clearance. If not, mark the height with a pencil and trim the bottom of the door. Find the center of the room or the room's focal point. Snap chalk lines down both the horizontal center and vertical center. If you have all the slate from one lot, you're in good shape. If, however, there are differences in the slate from box to box, open three different boxes to and rotate the tiles to get a random look.

Lay the Slate

Spread a layer of thinset for a section of six tiles in one corner where your lines intersect. Put down a tile and then use spacers and lay another tile. Complete the six tiles. You should have an idea of the number of tiles you can lay in a 20-minute period. This prevents the thinset from drying before you lay the slate. Continue to work from the center to the walls. Keep the rows straight and continually measure and lay chalk lines every two rows. Cut any pieces necessary with a wet saw.

Grout

Allow the area to dry. Clean the top of the slate and seal it before you grout. The sealer isn't necessary, but it helps any clean up after you grout. Put down the grout and wipe away excess from the top of the tile. Once it's dry, clean the grout. Use a soft cloth first; the less water, the better is always the rule when you clean grout. Wipe it clean with a damp rag and go over it one more time with a clean soft dry cloth. Continue until the slate is clean. Your last step is to seal the installed slate tile and grout with a sealer.