To install wood flooring over concrete, lay 6-millimeter polyethylene sheeting over the concrete, and use concrete screws placed at 16-inch intervals to fasten 3/4-inch pressure-treated plywood to the concrete. Finally, use a standard flooring nailer to nail the wooden planks directly onto the plywood.
Alternatively, screw rows of pressure-treated 2- by 4-inch studs at 16-inch intervals over the polyethylene sheeting. Ensure the stud rows are set perpendicular to the direction you intend to install the floor planks. Nail sheets of 3/4-inch pressure-treated plywood on top of the studs, and nail the wood flooring planks on top of the plywood. This reduces the amount of wood in contact with the concrete.
Another method is to use a plywood sub-floor, which involves gluing wood flooring planks to the slab. Remove all the baseboards using a pry bar, and remove any paint from the floor using a floor grinder. Clear the floor of dust and debris, and use a V-notch trowel to apply a liquid moisture barrier. Let the barrier set for 24 hours. Plan out your flooring layout, making sure to lay the planks parallel to the longest wall in the room. Use a V-notch trowel to apply the urethane wood adhesive onto the floor, and only spread enough for a few rows of flooring at a time. Use a rubber mallet to set the wood planks into the adhesive and connect the tongue of one plank to the groove of another.