Building a roof is a complex task that, for a beginner, may involve learning new terms. Rake, for instance, refers to the sloping edge, while fascia is the facing board that trims the sides. Soffit is where rafters overhang the wall and bird’s mouth is the triangle cut in a rafter to fit over wall cap boards. Barge or bargeboard is the outermost board on the end of a gable roof, usually on an overhang, fastened to extensions called “lookouts” or “fly rafters” over the end wall of the house.
Measure with a tape measure the width of the rafter or extension board that the barge will fasten to. The bargeboard needs to cover that completely. Use a 2-by-6-inch barge, for instance, to cover a 2-by-4-inch rafter or truss board. That will allow the barge to cover from the top of the roof cladding, typically 1/2 or 5/8-inch board, to below the bottom of the rafter or truss board.
Determine the angle for the barge board top cuts with a framer’s square. Put the thin side of the square at the angle cut of the rafter top with the heel or point at the bottom of that board. Make sure the square side and the rafter cut are perfectly aligned. Look at the wide side of the square and note where it hits the top of the rafter. That will show you the angle to cut the top of the barge board. Two barge boards, on each side of the roof, will join at the peak and slope to the sides.
Make that angle on the top of the barge board and cut it to the proper angle with a circular saw. Measure with a tape measure from the peak of the roof to the outside edge which the barge must cover. Mark that spot for an angle cut to match the angle of the top cut. Nail the barge board to the rafters or extension with a hammer and framing nails. This will require ladders and help.