Fascias, Soffits and Guttering: The Complete Guide

The fascia is the vertical board fixed to the ends of the rafters. It closes off the roof structure and carries the guttering, so it takes the full weight of a gutter full of water in a downpour.

The soffit is the horizontal board underneath, bridging from the fascia back to the wall. Its second job is ventilation: a ventilated soffit lets air into the roof void, which is what stops condensation forming on the underside of the roof in winter.

The bargeboard is the equivalent on a gable end, running up the slope. It has no gutter to carry but it takes direct weather and is often the first timber to go.

Flaking or blistered paint on timber fascia is the early warning. Once the paint film breaks, water gets behind it and the board starts to soften from the back where you cannot see it.

A gutter that has started to sag or tip is often not a gutter problem at all. The brackets are screwed into the fascia, and if the fascia has gone soft the brackets pull out. Refixing the gutter onto rotten timber lasts about one winter.

Green staining down the wall below the gutter line, birds getting into the eaves, or daylight visible at the eaves from inside the loft all point at roofline failure. So does a damp patch on an upstairs ceiling right at the outside wall.

For most houses, uPVC is the sensible answer. It does not rot, it never needs painting, and modern boards in woodgrain or colour finishes look far better than the shiny white plastic people remember from the nineties. A good uPVC roofline should give you twenty five years with nothing more than an occasional wash.

Timber still has a place on period and conservation properties where the profile matters, or where planning conditions require it. It looks right, but it needs repainting every four or five years to survive coastal weather.

The one thing to avoid is capping over rotten timber with uPVC. Cladding hides the problem and traps moisture against decaying wood. A proper job strips the old boards off, checks and repairs the rafter ends, then fits new.

Most homes have 112mm half round gutter, which is fine for a typical roof area. Larger roofs, steep pitches or areas that funnel water into one downpipe want a deep flow or square profile with greater capacity, otherwise it overtops in heavy rain even when it is perfectly clean.

The fall is what makes a gutter work. It needs a consistent slope to the outlet. A dead level gutter holds water, breeds silt and moss, and eventually sags in the middle.

Joints and stop ends are where leaks appear. Modern clip-in seals are reliable, but they need clean mating surfaces. A gutter leaking at one joint is a five minute fix if caught, and a damp wall if left for two years.

An overflowing gutter dumps water down the wall in exactly the place the wall was never designed to shed it. Over a winter that saturates the masonry, and saturated masonry means internal damp, cold rooms, blown plaster and eventually rot in floor and roof timbers built into the wall.

It also undermines the ground. Water pouring off the roofline at one point washes out pointing at low level and can find its way into a cellar or under a floor.

Clearing gutters twice a year, in late autumn and again in spring, is one of the cheapest pieces of home maintenance there is. If your house is near trees, make it three times.

As a rough guide, uPVC fascia, soffit and gutter replacement runs from around £70 to £110 per metre fitted, including stripping the old timber and disposing of it. A typical mid terrace front and back comes in between £900 and £2,000. A larger semi or detached with bargeboards is usually £1,800 to £3,500.

Scaffolding or a tower is needed on almost every job. As with chimneys, combining roofline work with other roof work shares that cost.

We check the rafter ends on every roofline job and replace any that have softened before the new board goes on. It is the difference between a roofline that lasts and one that sags again in five years.