gistfile1.php

<?php

add_action( 'genesis_setup', 'ssm_theme_setup', 15 );
/**
 * This function runs when the them is loaded and is responsible for running
 * all the action and filter hook functions that customize the theme;
 */
function ssm_theme_setup() {

	/** Run some code on the genesis before hook */
	add_action( 'genesis_before', 'ssm_open_root_markup' );

	// Move the footer outside wrap
	remove_action( 'genesis_before_footer', 'genesis_footer_widget_areas' );
	remove_action( 'genesis_footer', 'genesis_footer_markup_open', 5 );
	remove_action( 'genesis_footer', 'genesis_do_footer' );
	remove_action( 'genesis_footer', 'genesis_footer_markup_close', 15 );


	// Customize the entire footer
	add_action( 'wp_footer', 'genesis_footer_widget_areas', 2 );
	add_action( 'wp_footer', 'ssm_close_root_markup', 2 );
	add_action( 'wp_footer', 'genesis_footer_markup_open', 2 );
	add_action( 'wp_footer', 'ssm_do_custom_footer', 2 );
	add_action( 'wp_footer', 'genesis_footer_markup_close', 2 );

}

it's actually not possible to do this with hooks as the genesis_after hook comes after wp_footer in the markup. I think the only way to do it is to create a custom footer.php in the child theme