6. Use a circular saw to cut backer board just as you would cut wood or use a utility knife to score and pop it as you would drywall. Once all backer board is installed, cover the seams with joint tape, pushing it down with a putty knife. Next, load the putty knife with mastic and spread it over the tape, smoothing it out over the seams (figure E). Remove any excess mastic with a putty knife, then allow the mastic to dry according to the manufacturer's directions. 7. Sweep away any debris. Pop chalk lines in the same manner as the backer board, working from opposite walls and snapping the chalk lines so that a 90 degree angle is formed in the room center. Use a carpenter's square to double-check your lines (figure F).
8. Dust off the tiles you are about to lay. Have plenty of plastic spacers available. Use a 1/4-inch-groove trowel for this work (figure G). Start on the crosshairs and spread mastic in a small section onto the backer board (figure H). Comb mastic evenly. Lay the first tile at the intersection of the chalk lines and set it into place with a twisting motion (palms flat on the surface, fingers splayed, twisting the tile slightly side-to-side).
9. Repeat this step, using plastic spacers to maintain consistency in the design (figure I). Lay all full tiles in the first quadrant. Don't worry about cutting tiles to fit yet. Move on to the next section. Complete all quadrants. Use a damp towel to wipe away any mastic that emerges through the spaces.
10. You are now ready to cut tiles to fit the wall edges. Utilize a wet saw or manual tile cutter--both work great, but thicker tile should be cut with a wet saw. Tile nippers are handy for cutting around corners and rounded edges.