With the flap hanging over the top.
you pul the roll!
Costco!
I would install a toilet roll holder around 18" up off the floor. It should be around the height of your legs (or a bit higher) when sitting on the 'ol throne.
if close 21 inches if far 44 inches
Toilet T-issue Toilet Paper Direction Poll: http://www.judyreiser.com/poll.php