The house I recently purchased, built in 1973, has particle board subfloors. To clarify, this is not OSB and this is not just a particle board overlay over plywood -- the entire subfloor is 3/4" ...
I am about to install a hardwood floor into a room in my 1905 farmhouse. The subfloor is 8-12" wide 1" thick planks. The floor I am installing is 2-1/4" prefinished solid hickory tongue and groove. ...