Roof repairs and emergency roof repairs in Bath

Slipped slates are the most common sight on an ageing pitched roof, and the most misunderstood. A slate does not simply fall off. It slides because the nails that held it have given up, and the nails go for a reason. On many older roofs the fixings were iron, which rusts at the point where it passes through slate and timber. The nail weakens, the slate drops until the row beneath stops it, and eventually it comes away.

A single slipped slate after a gale is an ordinary repair. We replace it with a matched slate and hold it in place with a tingle, a short metal strap, cut from lead, copper or aluminium and nailed to the batten and bent up over the slate's lower end. The batten, incidentally, is the timber strip that every slate is fixed to. The result is neat and sound, and it does not disturb the slates around it.

Reading the pattern

What matters is how many slates are loose, and where. A handful at the edge of the roof after a storm points to wind. Slates dropping across several slopes with no weather to blame points to failing nails, and each repair then loosens the neighbours. At that point patching becomes a cycle, and re-slating becomes the cheaper course over the next few winters. You see photographs of the evidence, and we do not recommend a full replacement where repair genuinely works.

Tiles as well

Clay and concrete tiles slip for different reasons. Plain tiles are hung from battens by nibs and held by nails in every few courses, so a slipped tile usually means a broken nib or a missing nail. Interlocking tiles are clipped, and a lifted one may have lost its clip. Cracked tiles can be replaced singly, but the replacement has to match in profile and colour, or it looks like a patch. Reclaimed tiles often match best on older roofs.

Access and scaffold

Some repairs can be done from a ladder or a roof ladder, and some need scaffold or a platform, depending on the height and the position of the fault. We say at the survey which applies, because access is a real part of the price. The MyBuilder repair cost guide puts a minor job at £100 to £300, a moderate job at £500 to £1,000, and a major one at £2,500 or more.

If you can see slipped slates from the ground, photograph them and keep clear of the area below. The photographs help us plan the visit, and an insurer will want them if wind was the cause.

Figures: MyBuilder roof repair cost guide, 2026

Our short answers on repairing a slipped tile and a cracked roof tile cover the simple cases, and for the wider question of cost see what roof repairs cost. For slate in particular, our slate roofing page explains nails and re-slating. Whatever the covering, the useful first step is a clear photograph of the damage and a note of the date the problem began, since both help us judge whether a single repair will hold.

A valley is the sloping channel at the inside corner where two roof planes join. All the rain that falls on both slopes runs down into it, which makes it one of the hardest-working parts of any roof. A fault that would be trivial on an open slope can let in a steady stream here, and the stain inside often shows far from the cause.

Valleys are built in several ways. An open valley has a lining of lead, with the slates cut back at either side to leave the metal exposed. A swept valley curves the slates round the angle with no metal visible. A laced valley interleaves a wide slate from each slope. Concrete tile roofs often have a valley trough of plastic or glass-reinforced plastic (GRP). Each is repaired differently, and a repair that suits one will damage another.

What goes wrong

The commonest failure is a blocked valley. Leaves, moss and silt build up in the channel, water backs up, and it runs under the edge of the covering. A lead lining can also split along its length where it has expanded and contracted, and the splits are often too fine to see from the ground. Where a valley was lined in felt or a bitumen sheet, the material hardens and cracks with age. Sometimes the lining is sound but the slates beside it have slipped, leaving a gap for wind-driven rain to enter.

Behind the parapet

Some older Bath terraces hide their gutters behind a parapet, the short wall that stands proud of the roof edge. A parapet gutter is the lined channel running behind that wall. A box gutter is a similar lined trough set between two roofs or sunk inside one. Both are valleys in function. Casework from Bath Preservation Trust on a Grade I listed house in St James's Square records support for fresh lead in its central and side valley gutters, a reminder of how much work hidden valleys can need on a historic terrace. A mansard roof, with its steep lower pitch and flatter top, brings in more valleys wherever dormers meet it.

Because these channels sit hidden and run for a long stretch, a small crack can leak into an upper floor for a long time before anyone notices. We inspect them from the roof and trace them from the loft, and where a new lead lining is needed we fit it with proper falls to carry water away.

Repair, or relining

A single split can be repaired or patched with lead. A valley with many splits, or one where the boards below are rotten, needs relining. We lift the covering either side, replace damaged boards, lay the new lining in lengths with laps that shed water, and relay the slates. We tell you how long the problem section is, and what the choice costs, before we start.

Water that appears inside the building rarely appears where it enters, and our guide to finding a roof leak shows how we follow it. For more on the gutters at the roof's edge, see gutters, soffits and fascias, and for lined valleys and parapets the lead roofing page goes further. If you can reach a landing window safely, a look along the valley line after heavy rain, from inside, is often the quickest way to see where it overflows.

Gutters collect the water from the roof and carry it to the downpipes. When they block, the water has nowhere to go. It spills over the front, runs down the wall, or backs up under the lowest course of the covering. Over a season, that can soak the fascia, rot the rafter feet and wall plate, and show up as damp patches on an upstairs wall that seems nowhere near the roof.

Leaves, moss washed from the slopes and the grit that comes off ageing tiles are the usual causes. Overhanging trees add leaf fall in autumn, and a gutter beneath them can fill quickly. Cast iron gutters, which are found on older houses, can crack, rust through at the joints, or drop out of line when the brackets fail. Plastic gutters sag between brackets or leak at joints where the seal has perished. A gutter that has dropped out of line holds standing water, which adds weight and speeds up the problem.

What a blocked gutter does to the roof

The consequences reach further than the gutter itself. Where the underlay finishes before the gutter, overflow can run behind the fascia and wet the timber. A slate roof with a blocked valley gutter, or a parapet gutter with a blocked outlet, can overflow into the building. Standing water in a lined parapet gutter leaks through the smallest split, and sometimes the first visible sign is a stain on a ceiling two floors below.

Cleaning and repair

Clearing is the first repair. We remove debris by hand, flush the gutters to check the falls and the outlets, and look at every joint, bracket and downpipe. Many blockages are simple, and the repair is a clear-out and a new seal at a joint. Where a gutter has failed, the choice is between repair, relining and replacement. Cast iron can often be repaired and refitted in a way that respects the house. Our gutters, soffits and fascias page covers renewal and the roofline in full.

Gutters are best treated as part of the roof, and not as a separate system. We check them whenever we are on site, and mention anything we find on the way. The MyBuilder guide gives guttering at £30 to £70 per metre as a typical UK range for replacement, with scaffold adding to the cost on taller houses.

Keeping them clear

A clear gutter after leaf fall is the simplest piece of roof maintenance there is. If your gutters overflow in heavy rain, look for the pattern: overflow at one point suggests a blocked outlet or a dip in the run, and overflow along the whole length suggests debris or too few downpipes. Photograph what you see from a safe place, and send it to us.

For the roofline in full, see our gutters page, and for water that comes through a ceiling light, the answer on water through a light fitting explains what to do first. The guide to winter roof repairs covers frost and leaf fall, and what can be done on a cold or wet day. Clearing outlets before the first hard rain is a small job that spares you a larger one.