06-15-2013 12:48 AM
3/4 inch Thick Solid Wood Flooring and most all other hardwood flooring including Engineered or Floating engineered wood flooring and Laminate floors can be installed directly over 5/8" or 3/4" thick CDX plywood sub floors.
Although it is standard practice to install all hardwood flooring no matter the thickness, across the floor joists to support, stabilize and strengthen the whole floor structure sometimes that board direction is not preferred. If the existing sub floor is 3/4" thick, solid and flat with no deflection between the joists when walked on and the floor joists are spaced 16 inches or closer, you may be able to run the hardwood flooring parallel with the floor joists to obtain a desired look. Running the floorboards along the longest dimension of the room will make the room appear larger than it is.
Hope it helps~