Forty years ago a lot of industrial plant floors were wood blocks, and were Douglas Fir. In the 50's, the first plant I was in with the wood floors was the ALCOA plant in Davenport, IA (freshman in HS). The reasoning behind the wood was it was very forgiving on the lift trucks and other wheeled carts (usually steel or hard rubber wheels) and the reduction in noise.
Water leaks wasn't a pretty sight. Tar between blocks may have been to allow for some expansion normal with changes in humidity.
