Measure the height of the wall on which you are hanging the Hardibacker board using a tape measure. Lay a sheet of the board on a table and measure the height to determine if it requires cutting.
Place a straightedge perpendicular to the board across the location where you need to cut it. Hold the straightedge down firmly and draw the blade of a carbide-tipped scoring knife along the straightedge. Set the straightedge aside and grasp the side of the board, pulling it up sharply to snap off the unneeded portion.
Locate all of the studs in the wall using a stud finder tool. Mark the location of each stud on the ceiling or the floor with a pencil.
Place the Hardibacker board up to the left edge of the wall and insert 1 5/8 corrosion-resistant roofing nails every 8 inches into the studs with a hammer.
Continue cutting and hanging additional boards in the same manner, pushing the edges as close as possible.
Spread a layer of thinset mortar into all the steams between the boards using a trowel.
Press 2-inch mesh tape over all seams so it sits firmly in the thinset. Cut the mesh tape off flush with the ceiling and floor using a utility knife. Apply more thinset on top of the mesh tape until you can no longer see it.
Wait 24 hours to allow the thinset to dry completely and then proceed with installing the tile on the wall.