Duro Wesley Twin over Full Bunk Bed - Black What's Included Bunk bed. What's Not Included mattresses and bedding. Weight capacity: 320 lbs. top bunk, 400 lbs. bottom bunk. Mattress height should not exceed 8 inches; manufacturer recommends 6-inch thick mattress. Attached ladder sits above floor. Guard rails provide top-bunk safety. Rail height of top bunk 13 inches. 78.75L x 56.75W x 60.25H inches.