I would like to put in new bamboo flooring. I had a floor (sales) guy come look at my 1961 particleboard subfloor to see if it needed to be replaced. Both he and I agreed that removing the particleboard would be a good idea. Underneath the particleboard are 2x6 boards running diagonally throughout the house. I am wondering whether I can have the finished flooring placed directly on these diagonal planks the way it was done prior to the popularity of plywood? Or would it be better if I install 1/2" plywood as a subfloor and then install the finished flooring on top of that?