How to Build a Gable Cornice Return

Measuring

• 1

  Measure from the peak of your roof along the bottom edge of the roof line to the outside corner of the fascia. Write down the measurement. Use an angle finder positioned with one leg against each slope of the roof and the indicator pressed into the bottom of the peak. Divide the angle by two. Write down this result, also.

• 2

  Position the finder at the lower corner to which you measured, with one leg on the bottom edge of the front fascia and one against the face of the fascia going back away from the gable. Point the device up to check the angle and write down the figure.

• 3

  Measure from the front corner of the return to the back corner. Write down the measurement.

Cutting

• 4

  Set your compound miter saw by adjusting the turntable to the divided angle from the peak. Position the molding as it will be against the fascia and bottom edge of the roof --- the top of the piece will be against the saw's fence and the bottom will be on the table. Cut one end of your molding. Reset and cut the molding for the other face, setting the saw right of center for one and left of center for the other.

• 5

  Measure from the long point of that miter to the distance you recorded from the peak to the bottom corner of the fascia. Mark the back of the molding on the top edge at the appropriate distance. Position your compound miter saw with the table set to the angle you measured at the bottom corner of the fascia. Set the saw's bevel, or tilt, at 45 degrees.

• 6

  Cut the end of the molding so the blade runs through the mark you made on the top edge at the back. Reset the saw with the same angles, though tilted and turned in the other direction. Cut the end of the other molding piece for the other slope of the roof.

• 7

  Measure and cut the front end of your return using these same settings, but opposite. The left return gets cut at the right end and the right return at the left. Measure from the back top of this mitered cut to the length you measured from front to back of the return. Cut it flush.

Installation

• 8

  Nail the two pieces you made for the fascia, with the top edge against the bottom of the roof. The bottom edge will be against the fascia, angled as needed for the molding, just like you had it positioned on your saw. Use a pin nail gun and nail the molding with 1 1/4 inch nails. Place one nail every 12 inches along the top and bottom edges.

• 9

  Match the top ends at the peak so the miter is tight. Fill any gap with painter's caulk.

• 10

  Fit each return piece to the bottom end of the cornice molding. Nail the pieces in place, keeping the miter tight.