What is soffit and fascia?
Soffit is the underside of a roof overhang, and fascia is the vertical trim board that closes off the rafter ends at the roofline. Both protect the structure and support gutter systems.
Soffit and fascia are structural trim components installed where your roof meets your walls. The soffit is the horizontal panel that forms the underside of your roof overhang, while the fascia is the vertical board running along the roofline where the gutters attach. Though often discussed together, they serve different but complementary functions.
The soffit allows air to flow up into your attic through vents, part of your home's ventilation system that keeps moisture and heat from building up under the roof. Without proper soffit ventilation, you risk ice damming in winter and premature shingle deterioration. The fascia board bears the weight of the gutter system and protects the rafter tails and the wall below from weather exposure. Both are vulnerable to rot, insect damage, and deterioration if left unrepaired.
In Ontario, soffit and fascia are commonly made from aluminum, vinyl, or wood. Aluminum and vinyl resist rot and require minimal maintenance, while wood offers a traditional appearance but demands regular painting or staining. Damaged or missing soffit and fascia can lead to water infiltration, attic problems, and structural decay, making repair or replacement an important part of roof maintenance.