How to Make a Wooden Mantel

Choose the height you want for your mantel shelf. Draw a small pencil mark on the wall above the fireplace opening to mark the top surface of the mantel shelf. A common height for a mantel shelf is between 1 and 2 feet over the top of the fireplace opening.

Choose an intended width for your fireplace surround and mantel shelf. In most cases, people extend the mantel shelf 1 to 2-feet past both the left and right edges of the fireplace opening. Once you decide on this width, make a small pencil mark on both sides of the fireplace opening.

Use the reference marks from the previous step to draw longer lines on the wall to mark the width of the mantel shelf and surround. Lay a level against the reference marks and when it is perfectly vertical trace the edge of the level up the wall to 2 or 3 feet over the fireplace opening.

Lay the level across the reference mark you made in the first step, over the fireplace opening. Adjust the level as necessary and then trace the edge of the level until the line meets the lines you made in the previous step.

Measure the distance in inches from the top of the fireplace opening to the line that marks the top of the mantel shelf. Record this measurement to use in cutting the blocks to make the mantel shelf. Measure the total width of the shelf and record thi to aid in cutting blocks for the shelf.

Measure the distance in inches from the side of the fireplace opening to the vertical pencil lines. Record this measurement to guide in cutting the blocks to the intended length of the fireplace surround. Measure the distance in inches from the floor to the top of the fireplace opening to aid in cutting blocks for the mantel surround.

Use the measurements from step 5 to cut blocks for the mantel shelf. Cut sections of 2-by-6-inch boards into the necessary lengths to extend from the top of the fireplace opening to the line marking the top of the mantel shelf. Cut enough blocks so that when you stack the blocks, they reach a height that measures the same as the total width of the fireplace mantel shelf and surround.

Reference the measurements from step 6 to cut blocks for the fireplace surround. Cut sections of 2-by-4-inch boards to the length needed to fit between the sides of the fireplace opening and the vertical lines on the wall. When you stack the blocks, ensure you have enough blocks to match the measurement from the floor to the top of the fireplace opening. Remember you need enough blocks for both sides of the fireplace.

Sandpaper all wooden blocks to remove rough spots and sharp edges. Apply clear polyurethane or stain to the blocks to protect the wood from damage.

Start by attaching the fireplace surround blocks to the sides of the fireplace opening. Apply an industrial strength construction glue to one 2-inch length of a wooden block. Set the block into place against the floor with the glue-covered side against the wall and set into the space between the fireplace opening and the vertical line. Continue to place all 2-by-4-inch pieces in this fashion on both sides of the fireplace opening.

Attach the 2-by-6-inch blocks over the top of the fireplace opening. Again, apply glue to one of the longer 2-inch edges and stick the blocks into place over the fireplace opening so that the blocks fit into the space between the horizontal line and the top of the fireplace opening.