Hard-fired ceramic-clay tiles set in mortar on a concrete slab offer attractive, durable choices for outdoor patios or at poolside. Any outdoor tile must be frost-proof; purchase tile with an absorption rate of 6 percent or less.
Quarry tiles have a smooth surface and come in squares, rectangles, hexagons, and octagons of various sizes. Paver tiles are thicker than quarry tiles and are commonly cast in squares and hexagons with a textured surface and rough or rounded edges.
Mosaic tiles, mounted for correct spacing on a 1- or 2-foot-square mesh backing, make fast work of intricate designs. For outdoor use, choose mosaic tiles with a matte glaze so the surface will not be slippery when it is wet.
First, check the slab you intend to tile for flaws. To estimate the number of tiles you need, calculate the area of the slab (page 122), and purchase tile accordingly.
Note the position of expansion joints, if any, between sections of slab, and design your tile pattern around them (page 155). Lay a dry run of tile to ensure accurate placement. Plastic spacers or lugs molded into the edges of tiles help position them precisely.
You can cut quarry tiles with the hand tools shown on pages 156 and 157. Buy the micro-cutter and nippers; rent the more expensive senior cutter.
Tiles more than ½-inch thick require a circular saw with a silicon carbide masonry blade or an electric tub saw, in which water cools the blade and flushes away ceramic chips and dust. Regardless of the tool you use, always cut ribbed tiles across the ribs.
A tiled patio lasts longer and requires less maintenance when the mortar for anchoring the tiles and the grout for filling joints between them are made with a latex tile-setting liquid instead of water. Ceramic-tile grout comes premixed in a variety of colors; a 10-pound bag is enough for about 10 square feet of paver or quarry tile, or 20 square feet of mosaic tile. You can make your own grout by mixing equal parts of Portland cement and fine masonry sand with enough latex liquid to make a thick paste.
When you are ready to lay tiles, dampen the slab and trowel on a thin bed of mortar. Set the tiles in small sections while the mortar is still soft, planning the work so that you do not disturb freshly laid tiles.
Allow the mortar to cure 24 hours before grouting the joints. Do the grouting within the next 24 hours, however, to ensure a solid bond to the mortar.
To protect tiles and grout from stains, you can seal the finished paving with commercial masonry sealer or a 5 percent silicone solution. You may prefer to seal only the grout, which usually is lighter and more absorbent than the tile and shows stains more readily.
A typical tile
Outdoor tiles like the textured example above commonly have ribbed backs to improve the bond between mortar and tile. Most tiles are available in a bullnose shape, rounded on one edge or two and used along the perimeter and at the corners of a patio.
When cutting tile, wear safety goggles and heavy work gloves to protect yourself against chips and sharp edges.
A variety of shapes and colors
The square tile above, perhaps the most familiar, is just one of many styles available. Six-sided tiles are best used alone, but 8-sided tiles can be combined with small squares in an octagon-and-dot pattern (opposite, middle row, left). Besides traditional terra cotta, tiles come in many colors and patterns, including a wood-grain finish (above).
Repeating a single shape
Some patterns are inherent in the shapes of tiles. At far left is a stacked pattern of rectangular tiles—square ones are also suitable. At left is a honeycomb formed of hexagons; octagons may also be used.
Repeating two shapes
The octagon-and-dot pattern (right) builds automatically with 8-inch octagons and 3-inch squares, or dots. A square-and-picket pattern (far right) builds from 8-inch squares surrounded by 3-by 11-inch pickets.
Patterns from many shapes
Rectangular and square tiles, whose dimensions are multiples of the smallest unit, make a lively pattern with little cutting (near). The rubble pattern is achieved using broken paver tiles with their edges smoothed.
If there is an expansion joint, begin work there. For 6- or 8-sided tiles, set the first row to a far corner (above left, Arrow 1), trimming a tile at the end of the row if necessary. Extend the row toward the house (Arrow 2), leaving a gap at the joint; trim the corner tile as needed. Using the last full tile nearest the far corner as a guide, set a row of tiles perpendicular to the first, along the edge of the slab (Arrow 3). Alternate tiles may have to be cut. Set succeeding rows (Arrows 4 and 5) in the same manner, letting some tiles bridge the expansion joint, until the entire slab is covered. Finally, cut tiles to fill in the gaps remaining around the edge. For square or rectangular tiles in a simple stack pattern, follow the numbers (above, right) to set the first row out to a far corner. There, use the last full tile as the apex of a triangle, and set tiles in diagonal rows until one section of the slab is covered, then proceed with the other section. Cut tiles to fill any gaps left around the edges.
If the shape of the slab is irregular or curved, snap perpendicular chalk lines across its widest dimensions or use expansion joints to divide it into quadrants. Starting at the intersection near the center of the patio, lay tile along each axis toward the edges. Mark tiles for cutting as necessary. Then fill in each quadrant as shown left.
To tile around a tree or pool, first lay a rectangular frame around the obstacle, then fill in the frame as necessary with tiles trimmed to fit. Add an edge of border tiles, if desired. Divide the slab into quadrants, using a tile at the midpoint of each side of the frame as a reference point. Lay rows of tiles along the quadrant lines, and fill in each section with parallel rows of tiles. Cut the outermost tile in each row to fit the edge of the slab.
Using a senior cutter
Place a marked tile on the cutter plate, with the cutting line directly above the breaking bar. Set and lock the adjustable fence to hold the tile firmly in place. Slide the cutter handle toward you, then lift the handle until the scoring wheel rests on the line. Push the handle forward in one continuous motion, scoring the tile. Rest the flanges on the tile at its midpoint, then strike the handle sharply with your fist (right), causing the flanges to snap the tile over the breaking bar.
Using a microcutter
On the tile, draw a cutting line; it may be straight or gently curved. Set the scoring wheel on the line, hold the tile firm, and run the scoring wheel along the line in one continuous motion. For a straight cut, use a plywood scrap or uncut tile as a guide. Follow curves freehand. In either case, score the tile once; a second pass increases the chance of a ragged break. Center the jaws of the cutter on the scored line (above) and squeeze the cutter handles. The tile will snap along the scored line.
Cutting with tile nippers
Score a cutting line on the tile followed by a crosshatch pattern in the area to be cut away. Grasping the tile firmly in one hand, work from the edge toward the cutting line, chipping off small pieces. Hold the nippers with the jaws at an angle to the section of line you are approaching. When the rough cut is complete, smooth the edges with a piece of brick or a small stone.
Applying the mortar bed
Set dry-run tiles next to the slab, then spray the concrete with water in the area to be tiled first. Working in sections of 3 square feet or so, spread a thin layer of mortar over the dampened slab with the smooth edge of a rectangular notched-blade trowel. Turn the trowel and draw the notched edge through the mortar, leaving a pattern of uniform ridges. Keep a pointing trowel nearby for removing excess mortar and scraping dripped mortar from the slab. Rinse both trowels often in a bucket of water, to remove mortar before it dries.
Laying the tiles
Hold a tile by its edges and lower it onto the mortar bed with as little sideways motion as possible. Tap the tile with a rubber mallet to seat it firmly. Unless your tiles are molded with spacer lugs, lay plastic spacers on the mortar at the corners of the tile, then place the second tile against the spacers. Lay all the full tiles, checking the tiled surface every 4 or 5 tiles for evenness. When laying interlocking tiles near an expansion joint, stand ⅜-inch furniture dowels—available in bulk at hardware stores or home-improvement centers—between the tiles next to the joint (inset). Cut tiles for the edge of the slab as needed and mortar them in place. Allow the mortar to cure for 24 hours.
Grouting the joints
If you used plastic spacers between tiles—and they are less than ¼ inch below the tiled surface—remove them. Extract any dowel spacers near an expansion joint and gently fill the gap with strips of rolled newspaper to keep it free of grout. Place small mounds of grout at intervals along the mortar joints over an area 3- or 4-feet square. Kneeling on a piece of plywood to distribute your weight and avoid dislodging tiles, force the grout between the tiles with a rubber grout float dampened with water. Dip the float in a bucket of water occasionally to keep it wet.
Cleaning the tiles
Let the grout dry for about 10 minutes, but not longer than specified by the manufacturer. Wipe away any excess grout with a damp sponge, using a light, circular motion. Rinse the sponge often in clean water, but wring it well to avoid saturating the grout or washing the pigment out of colored grout. Mist the tiled surface with water every 4 hours for the first day, to let the grout cure slowly. After the third day, remove hazy grout residue from the tile surface by buffing with a dry cloth.
Filling the expansion joint
After the grout has cured, remove the rolled newspaper from the expansion joint and press ⅜-inch polyethylene-foam rope to the bottom of the gap (above, left). Fill any space remaining with silicone or poly-sulfide caulk (above, right), wiping excess caulk off the tiles immediately with the solvent recommended by the manufacturer. Let the caulk dry before walking on the tiles. If you intend to seal the tiles, wait a week or more to allow the grout to dry completely, then apply two coats of sealer.