How Do I Frame a Small Slope Roof Into Cinder Block?

Cut a 2 by 6 treated board the length of the roof that will be touching the cinder block wall. This will be your ledger board. Drill two rows of 1/4-inch holes through the board, one 1 1/2 inches down from the top, the other 1 1/2 inches up from the bottom; space the holes every 12 inches along the board's length. Lightly countersink these pilot holes so the concrete screw heads will run flush to the face.

Mark a line along the cinder block wall, using a level. Simply choose the height for the top of the roof, position the level with the left end at the left end of your proposed roof attachment, at this height. Adjust it to center the bubble, draw along its top. Flip the level end for end to the right, adjust and draw along it. Continue down the wall, drawing a level line.

Align the ledger board with the line along its top edge. Have at least two helpers hold the board in place and steady. Drill through each hole with a 3/16-inch rotary mason's bit to a depth of 1/8 inch to mark the pilot hole positions. Place the ledger on a flat, sturdy work surface. Drill each marked hole to a depth of 1 3/4 inches. Blow the dust from the holes.

Attach a 2 by 6 rafter joist hanger to the ledger at the left end. Use 1 1/4-inch treated deck screws in every hole on the left side, leaving the right side of the hanger open. Mark the ledger every 16 inches and install a hanger; make sure the last one is aligned with the end of the ledger. Use a framing square to keep them straight. Mark and add rafter tail hurricane ties to the top of the supporting wall opposite the cinder block in the same way, starting from the same end.

Hold the ledger in place and drive one 3-inch by 1/4-inch tapcon-style concrete screw into the cinder block wall in each pilot hole. Drive the screws in firmly until the head is flush with the ledger's face.

Drive one treated deck screw into the bottom edge of the ledger at the left corner. Drive one into the outside edge of the wall at the opposite end of the area to be roofed from the cinder block wall. Tie a string between the two screws. This represents the bottom edge of your rafters.

Position an angle finder in the corner formed by the string and the face of the ledger board. Position one angle of the finder along the line of the string and the other on the face of the ledger. Read the angle on the indicator in the center of the finder. Measure the string and add 6 inches for overhang on your rafter tails.

Cut enough 2 by 6 to fill every joist hanger, with the angle you discovered cut at both ends. Both cuts should run the same direction (two rights or two lefts) to form a parallelogram so that the rafter tail ends are vertical. Cut them to the length of the string, plus 6 inches. Measure the length from the long edge of one miter to the short edge of the other.