What is fascia in construction, and how is it built?
Short answer. In construction, fascia is the edge board fastened across the ends of the rafters or trusses where the roof overhangs the wall. Framers cut the rafter tails plumb and in a straight line, often install a structural sub-fascia, then add the finish fascia, which may be painted wood, PVC, fiber cement or wood wrapped in aluminum.
How the roof edge is framed
- Rafter tails or truss tails extend past the wall to create the overhang.
- Plumb cut: the ends are cut vertical and snapped to a straight line, so the fascia sits flat. Many tails also get a level cut on the bottom to give the soffit a nailing surface.
- Sub-fascia: a 2x board nailed to the tails ties them together and gives a solid backing for gutters. Not every house has one.
- Finish fascia: the visible board, sized to cover the tail and the soffit edge.
- Roof sheathing: runs out over the tails to the top of the fascia, and the drip edge laps over the fascia so water clears it.
Rakes are built differently
On gable ends there are no rafter tails to nail to. Builders frame a ladder of short lookouts, or rely on the overhanging sheathing, to carry the rake fascia. That is why rake boards sometimes sag or separate on older homes.
Finishes you will see
- Painted wood, the traditional choice.
- Primed wood wrapped in bent aluminum coil, very common in Georgia subdivisions.
- Cellular PVC or fiber cement boards that resist rot.
Where construction goes wrong
- Fascia installed too high, so the drip edge cannot lap it, letting water run behind the gutter.
- Uneven tails that make the fascia wavy and gutters drain poorly.
- No gap or flashing at the end grain, so water wicks in.
More in drip edge explained and roof anatomy explained.