How to Frame in Exterior Door Cinder Blocks

Measure and mark the doorway opening location on your cinder block wall. Use your tape measure to mark the wall to the height and width of the door frame. Use masking tape to create an outline of the opening.

Install a lintel over the doorway opening location to provide the strength necessary to support the wall once a large hole has been made. Use your circular saw equipped with a masonry cutting blade to create the slot into which the steel lintel will be placed. Cut into the wall about 1/2 inch above the top edge of the doorway opening outline. Extend the cut across the top of the door and about 4 inches beyond the edge of the door on both sides.

Insert the lintel into the slot and drive it into position so it's flush against the surface of your cinder block wall. Apply mortar to both ends of the slot and allow it to dry according to the manufacturer's specifications.

Make pilot holes at each corner of the opening outline to serve as guidelines for the outside cut. Use your power hammer drill and masonry bit to open a pilot hole through the wall at each corner of the tape markers. Use your circular saw to cut around the tape on the inside of the wall. Move to the outside of the wall and apply tape between each pilot hole, then cut along the tape lines to finish the opening.

Remove the cinder blocks from the doorway opening. Use a small sledge hammer to knock the top blocks out first, then work your way down until the doorway is completely open. The top edge of the doorway should be framed by the steel lintel you installed in Step 3.

Fill in the gaps and hollow portions in the open edges of the cinder block wall with mortar. Use your trowel to fill the spaces and allow it to dry according to the manufacturer's specifications. Insert the door frame for your specific exterior door model and fasten it to the inside edges of the opening.

Use your power drill to make pilot holes into the cinder block walls behind the door frame. Use a level to check that the frame is sitting perfectly plumb and adjust it accordingly with wooden shims. Use your screw gun to drive concrete screws through the door frame and into the wall to fasten it in place.