Birch hardwood flooring is a great alternative to oak and maple floors. The floor comes with a number of advantages: Options When you choose this flooring material you have a wide range of options to choose from. For example, you can choose to install paper, yellow or sweet birch. Paper birch is the softest and has a hardness of about 910 on the Janka scale. Yellow birch is a little bit harder than paper birch. According to experts, its hardness is almost equivalent to that of some oaks and green ash. Sweet birch is the hardest. It’s harder than sugar maple, white and red oak.