Unroll the flexible baseboard and leave it in the room where it is going to be installed. This lets the trim expand or contract, according to the room’s humidity.
Measure the wall where you want to install the base molding, using a measuring tape.
Cut the flexible baseboard molding to match the measurement you found in Step 2, using a handsaw.
Sweep the wall thoroughly with a broom to remove any dust or debris.
Apply a thin layer of construction adhesive to the flat back of the flexible molding.
Press the flexible molding to the curved wall. For an additional bit of security, tape it to the wall, using masking tape to hold it in place as the adhesive cures.
Allow the adhesive to cure for 24 hours.
Pound finish nails into the molding every 1 or 2 feet, using a hammer to help hold it to the wall.