Does the hardwood plank “have to” run perpendicular to the floor joists?
In some cases-Yes: when you have no sub-floor circa before 1940’s. An option: when your sub-floor is only 1″x 10″ planks installed on joists at a diagonal, but still running perpendicular would make a better and stronger floor. 1950’s – Today After homes were built using solid substrate materials such as a inch 7 layer plywood or inch OSB plywood etc. usually in a 4’x 8′ sheet. The direction of the floor is your option.
