The beauty and durability of granite make it an attractive and practical choice for flooring and countertops. Large expanses of granite slab are stunning, but prohibitively expensive for many homeowners. Granite tile, on the other hand, is less expensive in terms of both material and labor, as you can lay tile yourself. Although some do-it-yourselfers attempt to mimic the look of granite slab by butting granite tiles directly against each other to avoid grout lines, experts stress that some grout is necessary to stabilize the tile and prevent shifting. The trick is to lay the tiles close together, and then fill the spaces with grout that you've tinted to match the predominate tile color.
Fit the backerboard in place on the surface you're planning to tile. Lay it over a plywood substrate, whether you're tiling a floor or countertop. Use the backerboard cutter as needed to trim the backerboard so that it covers the entire surface with pieces butted together.
Spread a thin later of mortar under each piece of backerboard just before securing it in order to keep the board from flexing. Apply it with the smooth edge of the trowel, then use the notched end to texture it for better adhesion. Replace the board and secure it to the surface with several screws. Repeat this process until you secure all of the backerboard to the plywood substrate.
Fill the gaps between the pieces of backerboard with mortar. Work the mortar into the spaces with the trowel and then scrape the excess by swiping the trowel across the seams.
Apply fiberglass tape over the seams, and embed it into the mortar. Mortar over the tape and then swipe off the excess with the trowel so that the surface is smooth.
Lay out the tiles, and separate them 1/16 inch with spacers. For floors, measure several three or four tile spaces extending out from each end of the longest wall. Leave a 1/16-inch space along the wall. Mark the measurement with the grease pencil. Snap a chalk line between marks. The chalk line is the center of a tile joint. Repeat this several times, then measure corner-to-corner to make sure the corners are square. For countertops, measuring is unnecessary. Dry fit the tiles, beginning with full tiles.
Trim the tiles in the areas where full tiles don't fit, like along walls and around sinks and fixtures. Make the cuts with a wet saw.
Remove several tiles. Spread a thin layer of mortar over the backerboard with the even edge of the trowel, and then texturize the mortar with the notched side of the trowel. Replace the tiles one at a time, pressing firmly to work them into the mortar. Each tile should be level with the adjoining tiles. Replace the spacers. Repeat with the remaining tile until you have covered the entire surface. Tape tiles on countertop edges to hold them in place until the mortar sets.
Follow the manufacturer's instructions for allowing the mortar to set. After the recommended time has passed, remove the spacers from between the tiles. Spread grout across the tiles with the grout float, taking care to work it into the spaces between the tiles. Wipe off the excess grout with a damp sponge. The grout level should be slightly lower than the tiles.
Buff the tiles with a soft, dry cloth to remove the film left by the grout.
Allow the grout to dry thoroughly. Follow the sealer manufacturer's directions to seal the grout and the granite.