Grids by Foundation 5 need to add html class ".end" to the last element in ".row" element. This is how fix it by PHP.

add_class_last_elem.php

<?php
  
// make random color codes for background, to recognize betweens of each columns easily.

function rand_color() {
  return sprintf("#%06x",rand(0,16777215));
}

$color = rand_color();

$cols = 9; // the number of columns want to generate

$hexes = array($color);

for( $ci = 1; $ci <= $cols - 1 ; $ci++) {
  array_push($hexes,rand_color());
}

// $i count-up version

$header = <<<EOM
\n
<h2 class="text-center">\$i count up</h1>\n
<div class="row">
\n
EOM;

echo $header;

for( $i = 1; $i <= $cols ; $i++ ) {
?>

  <section style="background-color: <?php echo $hexes[$i -1];?>" class="columns small-4<?php if($i == $cols){echo " end";}?>">
    <div class="inner">
      <h1>Header</h1>
      <p>Templates systems are awesome</p>
    </div>
  </section>

<?php };
echo "</div>";
?>

<?php 
// detect the last element of array

$header = <<<EOM
\n
<h2 class="text-center">Array version</h1>\n
<div class="row">
\n
EOM;

echo $header;

foreach($hexes as $hex) { ?>
    <section style="background-color: <?php echo $hex ?>" class="columns small-4<?php if($hex === end($hexes)){echo " end";} ?>">
      <div class="inner">
        <h1>The last of elements in the array</h1>
        <p>Templates systems are awesome</p>
      </div>
    </section>

<?php }
echo "</div>";