What Are the Signs of a Rotten Fascia Board?

Start with the paint. Paint that peels in sheets, blisters or shows bare grey timber lets water in, and a board that stays damp for long enough starts to decay. Look along the bottom edge, where water collects, and at the joints and corners, where end grain is exposed and takes up moisture fastest.

Next look at the line of the board. A fascia that bows, sags between brackets or has a visible gap at a joint may be losing its hold on the rafter ends. A gutter that sits lower at one end, hangs at an angle or has pulled its screws out of the board is a strong clue, because brackets fixed into soft timber have nothing to grip.

Dark staining, a green or black fur along the lower edge and, in the worst cases, a mushroom-like growth or a damp, earthy smell all point to a wet board. Birds or insects using gaps behind the board are another sign of an opening. The word to remember is moisture: where it gets in and stays in, timber follows.

You can check a board by touch from a safe position. From a ground-floor window, a low roof you can reach without leaning out, or the top of a stable pair of steps with a helper, press the tip of a screwdriver gently into the lower edge and the underside. Sound timber resists. Rotten timber gives way, feels spongy and can be dug out in crumbs or long, dry fibres.

Do not push hard, and do not lean out from a ladder to do it. A board that is soft enough to fail under a screwdriver is also not a good thing to rest your weight on. If you cannot reach it without stretching, a photo taken with a zoom lens is better than a risky climb, and a roofer can judge from that.

Be aware that paint can hide a soft patch. A solid-looking surface may be a thin skin over hollow wood, and a dry spell in summer can make a rotten board look better than it is. If the board has been painted many times, the extra thickness can also seal moisture in. When in doubt, test along the length, not just in one spot, because rot often runs in a pattern with the water path.

The board you can see is only the front of the eaves. Behind it are the rafter ends, the soffit that shuts in the underside of the roof edge, and the eaves felt that should carry water into the gutter. Water that has soaked the board has usually passed through one of those, and rot can follow it inwards.

When a roofer takes a board off, they look at the ends of the rafters for softness, and at the wall plate beneath for staining. They check the soffit for sagging, since a damp soffit stains brown and bows downward. They look at the eaves protection to see whether the felt dips into the gutter or stops short and lets water run behind it. They also look for signs of insects or birds in the void.

If anything is found, the written price should say so. A small amount of damage can be cut out and spliced, but spread rot means new boards and sometimes new rafter feet. On older houses, it is also wise to check soffits for asbestos before anything is cut, as the HSE tells people to assume asbestos in buildings built or refurbished before 2000. Our answer on asbestos soffit boards explains more.

A small patch of soft wood at one end, with the rest solid, can be cut back and repaired with new timber spliced in and the whole board primed and painted. Larger areas need the board replaced. Where the board is sound but tired, a plastic cover can be fitted instead, which we compare in fascia capping against replacement. Capping hides rot as well as protecting good wood, so it should only go over timber that has been checked.

Leaving a rotten board is the one choice that costs more later. As it softens, the gutter drops, damp reaches the roof edge itself, and the repair grows from one board to a section of the roof. If you are not sure, a survey with photos of the board, once any gutter is lifted, shows what you have.

Any quote should say whether it covers the soffit and the gutter refit as well, and whether VAT and scaffold are in. Our gutters, soffits and fascias page lists the work we do, and our answer on sagging gutters shows how a failing board and a dropped gutter go together. Show us the corner that looks the worst and we will tell you what we would expect to find once the gutter is off.