How to Add an Exterior Basement Door Through Concrete Block

Cutting the Opening

• 1

  Remove the soil for several feet to either side of the chosen door site outside the concrete block wall. Make sure to dig to the base of the foundation and clear a space in front of the opening area that extends away from the wall at least as far as the basement ceiling is high, plus two or three feet for maneuvering room.

• 2

  Measure the outside dimensions of the doorjamb, taking both the height and width of the jamb to determine the size of the opening needed for the door. Add a 1/2-inch to the door width and 1/4-inch to the height to allow for a 3/4-inch clearance on all sides. Use a piece of chalk to mark the measured opening onto the outside of the block wall where you wish to add the door. Use a straightedge to help you keep the marked lines straight. Mark a second opening above and centered on the doorway opening to make space for the installation of a steel door header. Mark a rectangle onto the blocks, 6 inches in height and expanding outward from the edges of the doorway markings 6 inches on each side.

• 3

  Use a drill with a carbide masonry bit to place holes through the blocks on the inside corners of the two drawn openings. Connect the drilled holes with a straightedge on the interior side of the wall to recreate the drawn lines on the wall’s exterior.

• 4

  Mount a masonry blade to a circular saw, and then set the saw to cut at a depth of 2 inches. Line the blade of the saw with the chalk line on one side of the drawn door space at the bottom of the line. Press the saw’s trigger, and then begin cutting through the concrete block, working your way upwards along the line to the top of the drawn opening. Repeat the cut on the other side of the door opening, then across the top. Adjust the depth of the saw to 4 inches and make another pass with the blade over all three lines.

• 5

  Move to the interior side of the wall and use the lines drawn there to complete the cut through the blocks from the rear of the wall, also working in 2-inch passes.

• 6

  Break the cut section of the wall down from the inside using a sledge to punch through the blocks from the center of the wall outward to the edges.

• 7

  Repeat the cutting process for the drawn header space above the door.

• 8

  Fill the cavity on the inside of the partial blocks lining the opening greater than 1-1/2 inches in depth with a piece of 2-by-4-inch planking, cut to fit the block’s height. Place a layer of thinset mortar on the rear of the cut block of planking with a trowel, and then press the blocks into the cavity. Cover the blocks and the shallow cavities with thinset mortar pressed into place with the trowel, until you have a straight edge down the sides of the opening.

• 9

  Purchase a steel header cut to fit the dimensions of the cut header space in your wall. Place a layer of thinset mortar onto the sides and top of the header, and onto the tops of the blocks on the edge of the doorway opening. Set the header into position, and then fill any remaining gaps around it with mortar. Wait overnight to allow the thinset time enough to set for the doorjamb installation.

Installing the Door

• 10

  Use a tape measure to determine the heights of the dimples located on the sides of the doorjamb in frames constructed specifically for masonry attachments. Mark the dimple locations on the side of the wall opening onto the blocks with a pencil. Drill pilot holes into the blocks at the marked locations so that you can install the door frame anchors. Make the holes deep enough to match the length of the expansion bolts used to anchor the door in place, minus the width of the doorjamb.

• 11

  Place the doorjamb into the wall opening with the holes in the dimples within the frame aligned with the pilot holes drilled into the sides of the blocks. Place the expansion bolts into the dimples and then drive them through the door frame and into the blocks with a hammer. Make sure you drive the bolts far enough that the heads of each are flush with the frame.

• 12

  Fill the joint in the space between the doorjamb and the concrete blocks with caulking to create a seal.

• 13

  Screw the hinges to the door with a Phillips-head screwdriver, and then position the door within the door frame. Set the door so that its plumb and level within the opening. Use wood shims between the door and the frame if necessary to level the door into position. Screw the hinges to the door frame to secure the door into position.

• 14

  Install a lockset and handle to the door, following the set’s instruction manual.

• 15

  Place trim around the edges of the door covering the joint between the door and the blocks. Mount the trim using either construction cement, or by nailing it into position with concrete nails.