How to Set Exterior Tile
- 1). Inspect the surface of the concrete subfloor. If it is smooth, apply a liquid concrete bonding agent to the concrete, following the manufacturer's directions. This roughs up the surface so the tiles can bond to the concrete. If your concrete is rough, there is no need to treat it.
- 2). Identify any hills or valleys on the concrete floor by laying a 6-foot level on the floor in several spots. Wear down high spots with a sledgehammer and cold chisel, clearing away debris with a wire brush. Fill in low spots and cracks with fast-curing concrete patching compound, smoothing the surface of the compound with the side of a scrap of 2-by-4. Allow the compound to dry and cure overnight.
- 3). Dry-lay three tiles on the concrete with tile spacers between them. Measure the tiles end to end and mark the edges of the concrete subfloor at intervals equal to this measurement. Snap a chalk line between opposite marks, creating grid lines that will hold three by three groups of tiles. Trace the chalk lines with permanent marker, using the level as a straightedge.
- 4). Pour thinset mortar mix and the amount of water indicated on the package into a 5-gallon bucket. Mix the mortar using a 1/2-inch-shank drill with a mixing paddle attachment.
- 5). Spread thinset mortar on one section of the concrete subfloor with a notched trowel, dragging the notches along the mortar, creating grooves. Spread mortar on the back of a tile with a margin trowel and place it on the mortar, aligning the tile according to the grid lines. Continue setting tiles in this manner until the section of the grid is filled. Place tile spacers between the tiles to keep them evenly spaced.
- 6). Repeat Step 5 for the other sections of the concrete subfloor until it is covered with tiles. Let the thinset mortar dry and cure for two days, following the manufacturer's instructions. Slip a flat screwdriver between two tiles to test if the mortar is completely dry. If the mortar moves, let it dry for an additional day.
- 7). Remove the tile spacers. Mix latex-reinforced sanded grout mix with water in a 5-gallon bucket. Press the grout between the tiles with a grout float, scraping grout from the tile surfaces with the side of the grout float. Clean remaining grout from the tiles with a wet sponge. Drag the corner of a damp sponge along the grout lines to create an even depth.
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