I pulled up some damaged flooring in a home and found it to be 1" thick particleboard. In all my years of construction I never knew such stuff even existed!!!
My question is what is the best way to replace the stuff. I have found 1" plywood. Pricey stuff but I don’t need a a lot. It would be cheaper (not by much) to run furring strips of 1/4" on the joists and then 3/4" on top of that. This could cause a lot of floor squeaks.