What sizes does soffit come in?
Short answer. Vinyl and aluminum soffit panels are most commonly sold in 12 foot lengths, with widths of roughly 10 to 16 inches depending on the profile, in solid, center vented and fully vented versions. Fiber cement soffit comes in strips and 4 by 8 foot sheets, and wood soffit is usually ripped from plywood sheets to fit the overhang depth.
By material
- Vinyl soffit: commonly 12 feet long, in profiles such as double 5 inch, about 10 inches wide, and triple 4 inch, about 12 inches wide, with some lines offering wider panels. Panels run from the wall to the fascia and are cut to the overhang depth, so one 12 foot panel makes several pieces.
- Aluminum soffit: also usually 12 foot panels, often 12 or 16 inches wide, vented or solid. Stiffer than vinyl, so it sags less on deep overhangs.
- Fiber cement: panels and strips in several widths, plus 4 by 8 foot sheets, vented or solid.
- Plywood: 4 by 8 sheets ripped to the overhang depth, with strip or rectangular vents cut in.
Measuring your soffit
What matters is the overhang depth, measured from the wall to the back of the fascia, and the total eave length. Many Georgia homes have overhangs somewhere between about 12 and 24 inches, with some older homes shallower and some custom homes deeper. Deep overhangs may need a center nailer so panels do not sag.
Vented vs solid panels
Vented panels are what turn the soffit into the attic's intake. A common approach is fully vented panels along the eaves and solid panels on porch ceilings and other spots that do not open into the attic. Check each product's net free area per linear foot so the intake can be sized. Trim such as J-channel, F-channel and fascia cover is sold separately to match the panel system. See roof anatomy explained and roof ventilation basics.