Some fascia and soffit products are designed with easy installation systems that make it simple to fit your boards together at the right distance. You need a complete ventilation circuit between the soffit and the ridge to prevent extreme temperatures on your roof deck and heat migrating into your living space, followed by ice dams in winter. Underneath the rafters, a horizontal sheet of plywood paneling runs from the back of the fascia board to the face of the house wall, called a soffit. Chalk a line along the length of the fascia board, starting at the top the non-downspout end, 1 1/4 inches below the bottom of the roof's drip edge, instructs This Old House. First remove rotted or damaged wooden soffits. if you have confidence that your builder was good with the level-square-plumb aspect of his/her trade, you can estimate the location of the rest of the rafter based on that data. A typical asphalt shingle roof has a layer of wood based sheet material, usually plywood or chipboard, and normally with a layer of tar paper. horizontal mark is 80mm above soffit line). eHow may earn compensation through affiliate links in this story. At each corner, cut and install the channel so there is a 1/4-inch expansion at each of the adjoining walls. Continue cutting and installing the panels, locking them together as you go. Note that you can center the strapping at 24, 19.2, 16 or 12 inches, as desired, and that at any spacing it gives you 2.5" ("dressed" or planed 3") of target surface, not 1.5" as your dressed/planed 2" bottom chords do. Watch this video to find out more. Save my name, email, and website in this browser for the next time I comment. This hardly ever happens. Located under the roof eaves, a soffit vent is usually an intake vent that allows air to flow upward through the structure and then escape through a vent located higher up on the roof. Quality gutter installation usually makes use of fascia gutter brackets. Divide this by 2 to get the angle of your rafter tails. Roof leaks will not always be apparent on the ceiling directly below the leaky spots. Cut a hole inside the soffit and measure the thickness of the panel.