Guttering, soffits and fascias in Bath

The downpipe takes the water from the gutter outlet to the ground, where it enters a drain or a soakaway. Where the pipe is plastic, it is simply clipped to the wall. Where it is cast iron, it is held by ears, small lugs cast into the pipe, which are nailed or screwed into the masonry on pipe fixings. A pipe set tight against the wall can trap damp behind it, so older pipes are fixed slightly proud with a spacer, and ours are put back the same way.

A hopper, or rainwater head, is the open, box-like funnel at the top of a downpipe. It catches the flow from one or two gutters, or from a parapet outlet, and passes it into the pipe. On an older house the hopper is often a feature, cast with a date or a pattern. It also serves as a safety valve, since it is open at the top and the water cannot be held back as it would in a closed joint: if the pipe below blocks, the hopper overflows into the open air before water backs up into the wall.

Where pipes fail

Cast iron downpipes rust from the inside out and burst at the joint where the sockets overlap. A split in an iron pipe is usually near a joint, and you see damp stains on the wall in the same place every time it rains. Plastic pipes are less likely to rust, but sections can pull out of their sockets if the pipe is poorly supported, and a fixing loosened by frost or vibration lets the whole length lean away from the wall.

The bottom end matters too. A downpipe that discharges into a broken gulley soaks the base of the wall, and the damp rises into the masonry. The gulley is a small drain at ground level, and the usual faults are a cracked grid, a silted trap and a pipe that stops short of the grid and splashes onto the paving. We include the ground end in every survey, because a perfect gutter feeding a blocked drain still floods the wall.

Capacity

The pipe has to be sized for the gutter it serves. A large roof drained through a single small pipe will overflow in a downpour whatever condition the gutter is in. Corner positions matter as well: water arriving from two directions at an internal corner needs a wide enough outlet, or it jumps the front of the gutter at exactly that spot. Where the roof area is large we add outlets rather than hoping one pipe keeps up, and we place them to shorten the run of gutter between them.

The page on downpipes goes through materials, fixings and the ground end, and rainwater harvesting explains how a water butt or a tank can be fitted into a run without upsetting the drainage.

The soffit is the board that closes the underside of the eaves overhang, running from the back of the fascia to the wall of the house. From the ground you see it as a strip of flat board under the roof edge. It keeps weather and birds out of the roof void, and gives a neat finish to the overhang. On many houses it is also the intake point for ventilation, which is its quieter and more important job.

A roof space needs airflow. Moist air leaks up from the rooms below, and if the loft gives it no exit, it turns to water on the cold timbers and the underside of the roof covering. Over time, that damp feeds mould, rots timber and wets insulation. The usual answer is a continuous or spaced vent in the soffit, a strip of slotted or perforated plastic, which lets air in at the eaves. The air moves up the underside of the roof and leaves at the ridge or through vents higher up. Without the intake, the outlet does little.

Insulation can block the air

One thing we look for is loft insulation pushed into the eaves. It is easy to stuff a roll of mineral wool into the corner where the rafters meet the wall, and in doing so it blocks the path of the air from the soffit vent. A plastic tray fixed between the rafters holds the insulation back and keeps a channel open. This is a small piece of detailing that makes a large difference to how dry a loft stays.

Older boards and wildlife

Soffit boards on some mid-twentieth-century houses were made of asbestos cement. If your boards are of that age and type, they should be identified before anything is cut or drilled. HSE guidance on removing asbestos cement sets out how careful removal is treated, and we have suspect boards tested before we touch them.

Soffits and fascias are also places where birds nest and bats may roost. Both are protected, and when we see evidence of either, work pauses while we explain your options.

Plastic or timber

Vented plastic soffit boards are lightweight and need little upkeep. Timber boards are right on older properties but need painting and have to be fitted so that a vent can still be added. Aluminium soffits sit between the two. We suggest the one that suits the age of the house, and always include a vent.

Read more about soffit materials and the question of soffit vents, which sets out how many are enough and how to avoid blocking them. If you are planning a larger update, roofline upgrades covers combining the work in one visit.

The gutter run is a chain of lengths joined at unions, corners and outlets. Each join is a place where water can leak, which is why a leak so often turns up at the same spot every time it rains. The details differ by material, but the principle is the same: the joint has to be tight, watertight and free to move a little with the weather.

On plastic gutters, a union bracket clips two lengths together and a rubber seal inside makes the join watertight. The seals harden and shrink, and the lengths expand and contract with temperature, so joints start to weep. A new seal, or a new union, usually cures it. On aluminium, joints are sealed and sometimes riveted, and repair is a matter of resealing or replacing the length.

Cast iron joints

Cast iron gutters come in short lengths with a flange at each end. Neighbouring flanges are bolted together with a layer of sealing compound between them, traditionally putty or a mastic that stays flexible. When the compound dries, the joint drips. The repair is to undo the bolts, clean the faces, put in new sealant and tighten up again. If the bolts are seized, they are cut and replaced. A hairline crack in a length of iron, or a corner that has split, can sometimes be repaired, but a badly rusted length is replaced in new cast iron of the same profile.

Painting extends the life of cast iron more than any other single measure. Rust is removed back to bare metal, the iron is primed, and then painted inside and out. The inside is often skipped, but that is where the water sits, so it is where the rust starts.

Brackets

Brackets carry the weight of the gutter and the water in it, and they set the fall. Their spacing matters. Too far apart, and the gutter sags between them. Cast iron is heavy and wants a bracket at each joint and in between; plastic is light but still needs support at regular intervals, and extra brackets where it turns a corner. When brackets are fixed into a rotten fascia, they pull out, which is why the board behind them gets checked first.

We do not rely on sealant alone to hold a failed joint, as it hides the problem without correcting it. If a joint cannot be put right by resealing, the length is renewed. After any repair we run a hose along the gutter from the high end, watch every joint and every bracket under load, and only then call the run finished. A gutter that looks tidy when dry can still weep when full, so the water test is the proof we rely on.

Figures: MyBuilder gutter, fascia and soffit replacement cost guide, 2026

Our short guide to a leaking gutter joint explains what to look for before you call, and how long gutters last helps you judge when repair has stopped being sensible. For the cost side, see guttering cost.