function joints_wpsearch($form) {
  $form = '<form role="search" method="get" id="searchform" action="' . home_url( '/' ) . '" >
  <div class="small-10 columns no-pad">
    <input type="text" value="' . get_search_query() . '" name="s" id="s" placeholder="'.esc_attr__('Search the Site','jointstheme').'" />
  </div>
  <div class="small-2 columns no-pad srchBtn">
  </div>
  </form>';
  return $form;
}

function custom_search( $form ) {
  $form = '<form role="search" method="get" id="searchform2" action="' . home_url( '/' ) . '" >
  <div class="medium-11 small-10 columns no-pad">
    <input type="text" value="' . get_search_query() . '" name="s" id="s2" placeholder="'.esc_attr__('Search the Site','jointstheme').'" />
  </div>
  <div class="medium-1 small-2 columns no-pad">
    <input type="submit" id="searchsubmit" class="srchBtn2" value="" />
  </div>
  </div>
  </form>';
  return $form;
}

add_filter( 'get_search_form', 'joints_wpsearch' );

add_filter( 'get_search_form', 'custom_search' );

<?php get_search_form('custom_search'); ?>

<?php get_search_form('joints_wpsearch'); ?>