STEP 1 Remove the new Fineline planks with the 5G8 joint from any packaging. Leave them exposed in the room with the existing floor for at least 48 hours so they can acclimate.
Use a skillsaw set to slightly more than the depth of the flooring to cut the damaged board as show above. Stay at least 2" back from adjacent boards on all sides.
STEP 3 Use a sharp chisel to complete the cuts all the way to the four corners. Remove the center section. Keep this removed piece to use later in the process.
STEP 4 Lift up the sides to unlock joints. Then remove the short ends.
STEP 5 On the replacement boards, use a table saw to completely remove the bottom groove from both the long and short sides of plank.
STEP 5a The edge with groove removed will look like this.
STEP 6 Remove the tongue on the short end of the plank. (Leave it on the long edge.) Make certain it is removed flush with the face of the plank. Do not cut into the face of the plank.
STEP 6a The edge with tongue removed will look like this.
STEP 7 Slide a membrane of red rosin paper or plastic on both long and short existing tongue sides. Place it slightly under the existing planks and roughly 2" into the space created for the new plank.
These floors are designed to float. The membrane is to keep you from gluing the new plank directly to the subfloor.
STEP 8 Cut your replacement plank to length. Dry fit your new plank to make sure it cut properly. Engage the tongue and then hinge board into place.
Never hit the plank directly with your hammer. Always use a wood tapping block. Be careful not to damage any adjacent boards.
STEP 9 Run a 1/4" bead of construction adhesive from under the tonges out 1" onto the membrane. Repeat every 3" on long and short sides.
STEP 10 Place a continuous bead of adhesive along both tongues.
Apply glue liberally to groove, as shown.
STEP 12 Install the replacement board as shown in Step 8. Remove any excess glue from surface with damp cloth. Take the cut-out damaged piece and place it over the overlapped joint. Weight it down with roughly 20 lbs every foot and let dry for 24 hours.