DrDoc - 5:29 pm on Sep 26, 2013 (gmt 0)
Depending on the layout of the page, there are a couple ways of getting a footer to shift below something else.
For floated columns, simply use
clear: both on your footer div. This will force it to clear whichever is the tallest element, whether floated to the left/right.
Otherwise, if there is a "wrapper" container in which both the main content area and columns reside together, and that wrapper ends up extending in height to fit the tallest, you can simply place the footer below this wrapper.