1) Metal Fireplace Installation
Draw a level line representing the bottom of the mantel and a mark on each side to represent the ends of the mantel on the wall above the fireplace. Locate the king stud or other appropriate wood members on each side of the fire place box. If you have set up 4x backing for this during framing, use the backing. Drill a 3/8″ hole in the center of each stud which represents the vertical center of the mantle. Screw a ½”x 10″ lag bolt, into each stud leaving approximately 6″-7″ protruding into the room perpendicular to the wall. If they are not straight, bend them so that they are. Cut the hex head off with a metal cutting blade. Carefully measure the distances from the end marks and from the bottom line to locate the holes to be drilled in the back of the mantle. Mark the corresponding bolt hole locations on the back of the mantle and drill using a 9/16″ drill bit. These need to be drilled approximately 1″ deeper than the distance the bolt protrudes from the wall so that any shavings which result from pushing the mantle on will have someplace to go. If you have corbels, mount them on the mantel at this point by blind screwing them to the bottom of the mantel. Additionally, you may want to mortise the corbels into the bottom of the mantel for a more refined appearance. Now lift the mantel, locate the holes and push it onto the lags. Once snug against the wall, you can blind screw it and glue it to the wall to insure against movement.
2) Masonry Fireplace Installation
You will use all of the above procedures except that you will use a masonry anchor bolt instead of a lag bolt. Insure that the locations used for the anchoring are solid grouted and not hollow.
How to select reclaimed mantel