you can write a custom class to extend Walker_Nav_Menu in your functions.php, in this class you can change all the markup
the more simple is to copy all the class from /wp-includes/nav-menu-template.php and modify what you want
class Walker_Nav_Foundation extends Walker_Nav_Menu {
function start_lvl() // to change opening <ul>
function end_lvl() // to change ending </ul>
... etc ...
}
and call it in your template
<?php wp_nav_menu( array( 'theme_location' => 'primary', 'walker' => new Walker_Nav_Foundation() ) ); ?>