If your mantel will be mounted on a fireplace where stone or brick will be installed at a later date, then we recommend using steel straps to mount your mantel. Straps are pre-drilled with holes every 2 inches. We suggest you use one strap per 25 pounds (example: 4 straps for a 100 pound beam). As a general guideline, use 3 straps for beams under 6 feet, 4 straps for anything over 6 feet.