I have some old hardwood flooring in my house and I'm considering installing new hardwood floors as it's not in the best shape. The house was built in the 1940's and has an older type of subfloor that runs at a 45 degree angle to the joists - I think it's 1x6s. I've read that the suggestion is to always run the hardwood perpendicular to the joists, but curious if that wisdom still stands for this older subfloor layout.
To elaborate a bit, given the 45 degree angle of the subflooring, for structural reasons, is it still recommended to run the hardwood perpendicular to the joists? Or does that guidelines not apply in this case?