How to Install Original Plank Flooring

Lay a hardwood plank on a piece of underlayment, and set it next to a door jamb. Mark the jamb where the underlayment and plank meet, and cut through it with a pull saw. Repeat the process on the adjacent jamb in the doorway to make room for the flooring planks to slip underneath. Pry off cut sections of the door jamb and the casing with a chisel.

Unroll a sheet of underlayment over the prepared subfloor. Overlap adjacent sheets by 2 inches, and tape their edges to secure them together.

Snap a chalk line along the floor, three-eighths of an inch from the longest and straightest wall -- where you'll lay the planks. Also, snap a chalk line on the floor against the remaining walls. The 3/8-inch gap allows for expansion.

Lay the first plank on the floor, flush against the chalk line, with its grooved edge facing the wall. Slide the end of another plank into the end of the first one, to snap them together. Repeat the process of installing full-length planks for the first row or course.

Measure the gap along the end of the first row and cut a length of plank to size, minus three-eighths of an inch for expansion. Snap the end of this plank into the end of the previous plank to complete the installation of the first row.

Use the remaining plank from the cutoff as the starter plank for the second course, so the joints in the hardwood flooring planks are staggered. Slide the groove edge of this cutoff piece into the tongue edge of the plank along the first row to join them together, forming a tight seam. Continue to lay the remaining full-length planks for this row, and the subsequent rows.

Use a utility knife to slice the tongue edge off the plank in the row just before the door jamb -- because you have to notch the plank to fit under the jamb, not join it to the previous plank. Cut this last plank in the row to the required length, so it fits the space, minus 1 inch to allow for the transition piece.

Align this plank next to the previous plank. Mark the notches for the door jamb on this plank, using a pencil, so it slides under the trim. Join the marks with a square, and cut using a jigsaw, so it fits the door jamb.

Apply a thin layer of adhesive over the edge of the plank where you removed the tongue. Insert the notched plank into place, flush against the glued edge of the previous plank. Tap the joint lightly with a mallet.

Measure and cut a piece of transition molding to fit between the jambs. Apply a thin layer of adhesive over the exposed edge of the subfloor, and press the molding against it, until secure.

Attach shoe-molding strips to the floor to cover the expansion gaps, using 4d nails.