How to Lay Slate Tile on a Concrete Porch

Laying slate tile on a concrete porch is a similar project to laying it on an interior floor, with the tiles set in mortar and the grid pattern of the tiles starting at the center of the floor and building outward toward the walls. However, when tiling outdoors, you should lay down a special underlayment, called an uncoupling membrane, which absorbs any movement in the concrete due to climate changes, so it doesn't crack the tiles.

Things You'll Need

• Thinset mortar
• Notched mortar trowel
• Uncoupling membrane for outdoor tiling
• Utility knife
• Chalk snap line
• Slate floor tiles
• Tile spacers
• Wet saw
• Grout
• Grout trowel
• Sponge

Instructions

1. Spread thinset mortar over one edge of the porch, using a notched mortar trowel. Cover enough floor area to encompass one strip of uncoupling membrane running all along the floor.

2. Press strip of uncoupling membrane into the thin set mortar, cutting it to fit with your utility knife. Press the membrane down firmly.

3. Lay additional strips of membrane in the same fashion, side by side, working your way across the porch. Cover the whole surface. Let it set for 12 hours.

4. Divide the membrane-covered surface into four quadrants, using a chalk snap line. Spread thin set mortar over the middle of the intersection with your trowel, covering a few square feet.

5. Set slate tiles in place at the intersection, along the lines, with spacers between them. Spread additional mortar and lay additional tiles, building out from the middle toward the edges of the porch. Cut the tiles at the edges as needed on a wet saw.

6. Let the thin set mortar dry for 12 hours. Remove the spacers.

7. Grout the floor starting at the one corner of the room and working your way out. Press the grout into the lines while scraping it off the surface of the slate. Wipe up the excess with a damp sponge. Let the grout set for 48 hours before walking on it.

References

• Schulter:Tiling on Exterior Surfaces with Uncoupling Membrane

Resources

• Read this Article in Spanish