How to Build a Mantle Over a Brick Wall With a Gas Insert

Building the Mantel

• 1

  Set two 1-by-5-by-36-inch hardwood boards next to each other on the working surface. Place the boards parallel and on their long, thin surfaces. Keep them 3 1/2 inches apart, as they are the mantel’s top and bottom. Slide two 1-by-3 1/2-by-5-inch hardwood boards in between them. Move these smaller boards toward the ends of the top and bottom boards to become the side boards. Adjust the four boards until they make a 5 1/2-by-36-inch rectangular frame.

• 2

  Position two metal L-brackets along each joint inside the frame. Mark each attachment screw hole and remove the brackets. Drill out the holes, being careful not to drill all the way through the boards. Replace the brackets and fasten them with 1-inch wood screws.

• 3

  Set a 1-by-7-by-37-inch hardwood board with its best side face down on the working surface. Position the frame evenly on top of this board, which is the mantel’s front board. Set 1-inch metal L-brackets every 6 inches along the frame’s inside where the frame meets the front board. Mark the screw hole locations. Drill each hole and attach the front board to the frame with 1-inch wood screws.

Installing the Mantel

• 4

  Locate the gas line in the wall. Contact a professional if you’re unsure. Even to avoid a gas line puncture can lead to an explosion. Mark the gas line’s location.

• 5

  Position a 1 1/2-by-3 1/2-by-34-inch board over the fireplace, centered on the fire and in the exact location where you want the mantel installed. Setting a carpenter's level on the board’s top ensures that it is straight. Drill holes every 6 inches into this board, which becomes the mantel bracket, and into the brick wall using a hammer drill. Make sure the hammer drill is on the hammer setting at full power. Avoid the gas line.

• 6

  Drill a hole if necessary for the gas insert, which may protrude from the desired area of the brick wall.

• 7

  Fasten the bracket to the wall with 5-inch masonry screws.

• 8

  Set the mantel over the bracket. Drill out necessary spots in the mantel so the gas insert protrudes from the mantel.

• 9

  Slide the mantel onto the bracket until it is flush with the brick wall. Drill holes every 8 inches up through the mantel’s bottom and into the bracket’s center. Drill holes every 12 inches through the mantel’s top into the bracket. Attach the mantel to the bracket using 3-inch wood screws tightened into each of these holes.