What holds a soffit in place?

What holds a soffit in place is a combination of framing, channels, and fasteners that secure soffit panels under the roof overhang and keep them from sagging or blowing off. Soffit panels, which are typically vinyl, aluminum, or wood, are held by J-channels or F-channels that are nailed to the wall and fascia board, creating tracks that soffit panels slide into, with one channel along the wall and another along the fascia board. The panels themselves are often interlocked or overlapped and secured with nails, screws, or staples to the underside of rafter tails or to soffit framing that runs between rafters, with fasteners placed in the nailing flange of vinyl or aluminum panels. For wood soffit, boards are nailed directly to rafter tails and blocking. Soffit framing, which is 2x4 lumber installed between rafter tails or on top of wall plate, provides solid nailing surface for soffit panels and is essential for support, especially for wide overhangs over 16 inches that need intermediate support to prevent sagging. In addition, fascia board at edge of roof holds outer edge of soffit, and wall holds inner edge. Vented soffit panels have perforations for attic ventilation and are held same way. Proper installation with adequate fasteners every 12 to 16 inches prevents soffit from coming loose in wind, and ensures ventilation is maintained to prevent ice dams and moisture that cause rot.