What's the Difference Between a Soffit and a Fascia?

Where each one sits

Stand outside your house and look up at the edge of the roof. The roof usually overhangs the wall by a short distance, and the ends of the rafters, the angled timbers that hold up the roof covering, stick out beyond the wall. Two boards finish that edge. The one you see straight on, facing outward and running along the bottom of the roof, is the fascia. The one you see by tilting your head back, running flat from the fascia back to the wall, is the soffit.

The fascia is fixed to the front of the rafter ends. The soffit is fixed to the underside, usually resting on a small timber ledge called a soffit bearer or on a wall plate. Together they form an L-shaped box that wraps the rafter ends. The gutter hangs from the fascia, or from brackets fixed to the rafters through it. The basics page what fascias, soffits and guttering are shows the parts in more detail, and the bargeboard, which does the same job on a gable, is explained in what are bargeboards.

A quick way to remember it: the fascia faces you, and the soffit faces the ground. The word soffit comes from an old term for something fixed underneath, and fascia from the Latin for a band. If a roofer or a quote mentions only one, ask whether the other is included, since the two are often priced together as a roofline set.

What each one does

The two boards share a job, which is to protect the roof timbers, but they do it in different ways:

• Fascia: holds the gutter, hides and protects the rafter ends from rain and rot, gives a straight line along the edge and supports the bottom of the roof covering.
• Soffit: closes the gap under the overhang so that birds, wasps and weather cannot enter, protects the underside of the rafters and, where vented, lets air into the roof space.

The vented soffit is the part many people miss. Air that enters the loft through the eaves flows up and out through the ridge or high-level vents, and this movement carries off damp air before it condenses. A solid, unvented soffit on a roof that needs ventilation can lead to damp. Our page on soffit ventilation explains the airflow.

Some roofs have a variation. On a house with no overhang, a flush eaves, there may be a fascia but no soffit at all, because the roof stops at the wall. On a house with a deep boxed overhang, the soffit may be wide, with a separate board hiding the junction at the wall. Some modern roofs use a single combined board, but the two jobs still have to be done, so the parts are present even when they look like one.

Materials and common problems

Both boards come in painted softwood, uPVC, aluminium and composite. Timber was the norm until the 1970s and 1980s, and uPVC took over after that. The two boards age differently because they face different weather. The fascia takes rain from the roof, overflow from a blocked gutter and sun. The soffit is sheltered from direct rain but catches damp from a leaking gutter, condensation and birds. A rotten fascia is a frequent complaint, and rotten fascia boards explains how to spot it. A stained or sagging soffit usually means a gutter leak above it or a hole at the eaves.

One extra caution applies to older houses. Soffit boards made before 2000 were sometimes asbestos insulating board, so do not drill, cut or break a suspect board; read could my soffits contain asbestos first. Fascias in older houses were usually timber.

Colour is a choice that affects both boards. White is the most common, but black, grey and woodgrain are all available, and whether gutters should match fascia and soffit helps you decide. Whatever you choose, the soffit and fascia should be the same make so that the joint between them stays tight and weathers evenly.

Replacing them, and who to ask

Fascias and soffits are normally replaced together, along with the gutters, because they share the same access and the same scaffold. Fitting new fascias but leaving a worn soffit leaves a weak edge that fails soon after. The usual order of work is in the roofline replacement process, and costs for typical houses are on how much soffits and fascias cost. If you only want a cover over timber that is sound, see fascia capping vs replacement.

When we survey a roofline, we photograph each board and tell you which parts are sound, which need replacing and why. The service is described on the guttering, soffits and fascias page. Fixed written figures follow the visit.