Eigenvector wrote:

What would be best here, run the planks widthwise or lengthwise? I have to
tie the planks together in a way that is very durable and strong - I will be
running on these things and so it has to take approximately 300 lbs of
impact for long periods of time.

My LifeFitness 9100HR has tongue and groove planks running lengthwise
over a few cross supports. The supports are not attached to the deck,
only to the frame. The machine has a wax dispensing tank that lubes the
deck.

This is a pro treadmill with 45,000 miles on it to date. The deck has
been flipped to the second side at 41,000 miles. My buddy that repairs
these for living, and found me this one used, sees oak decks go
80-90,000 miles in commercial applications.