Eave anatomy — soffit, fascia, sub-fascia, and the F- and J-channel that hold the soffit
The soffit floats in an F-channel at the wall and a J-channel at the fascia. Vented soffit is the intake half of attic ventilation.
What this diagram shows
A cross-section through a roof overhang. A rafter tail projects from the wall to the outer end, where a wood sub-fascia carries the gutter and a fascia cladding covers it. A vented soffit panel spans the overhang, floating between an F-channel at the wall and a J-channel at the fascia so it can expand. Arrows show intake air drawn up through the vented soffit into the rafter bay and attic, per IRC R806.
Use this diagram — free
You're welcome to use this diagram on your own site, blog, handout, or lesson at no cost. The only condition is a visible credit link back to the source page. Copy the snippet below and paste it into your page — the credit is already included.
Please keep the credit link intact and don't alter the diagram itself. Redistribution as part of a competing diagram library or template pack isn't permitted. Questions? Reach us via the site.
Was this diagram helpful?
Soffit & Fascia Calculator
Free soffit and fascia calculator — soffit panels, fascia boards, and F- and J-channel from your eave run and overhang depth, with vented-intake guidance.
