If you are having lead work done in Saffron Walden, knowing what a proper job looks like - from the first inspection to the final tidy-up - means you can tell good work from rushed work.
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A proper lead work job starts on the ground, not on the roof. Before any scaffolding goes up, a roofer should be looking at the property from below - noting the chimney stack height, the roof pitch, the type of tiles or slates, and where each flashing runs. This tells them how much lead will be needed, which Code is appropriate, and whether there are any obvious signs of previous repairs or bodge work to account for.
Once access is arranged, the first task on the roof itself is a thorough inspection of the existing flashings. This means lifting any loose sections carefully, checking the mortar in the chases, looking for cracks or corrosion in the lead, and assessing whether the back gutter (on a chimney) is the right size and properly formed. None of this should be rushed. Misdiagnosing the problem at this stage leads to repairs that fail again within a couple of winters.
The roofer should also check the surrounding tile or slate work. A failing flashing often allows water to track beneath tiles and wet the felt, which can accelerate felt deterioration. If any tiles are cracked, slipped or missing nearby, those need noting at this stage.
Where the existing lead needs to come off, it is stripped carefully. Good roofers take the old lead away for recycling - lead scrap has value, and responsible disposal matters. The lead should not simply be ripped off. Pulling flashings out of mortar chases carelessly can dislodge pointing and, on older stacks, loosen brickwork.
Once the old lead is removed, the chase (the groove cut or raked into the mortar joint to receive the flashing) is cleaned out thoroughly. Any old wedges, clips or mastic sealant is removed. This is also the point at which any rot in adjacent timber - such as the wooden fillet behind a dormer or the fascia below a gutter - can be identified and dealt with before it is covered back up.
The mortar chase needs to be at least 25mm deep to hold the lead securely. If the original chase was shallow or the mortar has crumbled over a wide area, it may need to be raked out further before work begins. On older brickwork, this requires care - a cold chisel and careful hand work rather than a disc cutter wherever the brick face might be soft.
Any timber fillets (the triangular timber sections used at the base of dormers and abutments to create a smooth transition from wall to roof) are checked and replaced if they have swollen, rotted or shifted. A fillet that has moved even slightly will prevent the new lead from lying flat, creating a gap that lets water in.
On flat roof abutments, the upstand height is checked against the roof surface level. The lead upstand should be at least 150mm above the finished roof surface to prevent water from overtopping in heavy rain. If the existing detail was undersized, this is the stage to correct it.
This is the skilled part of the job. Lead sheet is cut to size on site using a knife and straight edge, never pre-ordered in fixed sizes that are then forced to fit. For chimney stacks, this typically means cutting step flashings (the pieces that step up the side of the stack with the roof slope), soakers (the small pieces that interleave with slates or tiles), a back gutter piece behind the stack, and a cover flashing over the front.
Each piece is dressed - bent, folded and shaped - by hand using a dresser and bossing mallet. The dressing must create clean, tight folds at all internal and external angles. Split or cracked corners at this stage are a sign of lead that has been worked too cold or too roughly.
Bay lengths are kept to a maximum of around 1.5 metres for Code 4 lead to allow for thermal expansion. Where a run is longer than this, a drip or roll joint is formed between bays. This is not optional - leaving out the drip joints to save time is one of the most common causes of lead buckling and splitting within a few years.
Lead is fixed with lead clips, tucked into the chase at the top edge, and held by wedges. It is never nailed through the face - a nail hole through the face of lead creates a direct water entry point.
Once the lead is in position, the chase is pointed with mortar. The mix matters. A mortar that is too strong (high cement content) is rigid and will crack as the lead moves. The pointing should be slightly weaker than the brickwork itself - a 1:3 or 1:4 cement:sand mix is typical for most domestic brickwork, though lime mortars are used on older buildings where the brickwork is soft.
The pointing is pressed firmly into the chase above the lead, tooled to a slight outward slope to shed water, and finished neatly. It is not raked back or left proud. Sloppy pointing at this stage is a visible sign of a rushed job, and pointing that does not fully seal the chase will allow water to enter from above.
New lead is bright and reactive. Without treatment, rain washes lead carbonate down the roof, leaving white staining on brickwork and tiles. Patination oil is brushed onto the surface of all new lead before the scaffolding comes down. It reacts with the lead surface to form a stable patina that prevents the staining and gives the lead its characteristic grey appearance.
Skipping patination oil is a shortcut that causes cosmetic problems and, in some cases, accelerates surface degradation. It takes ten minutes and costs next to nothing - there is no good reason to leave it out.
Once the lead is in, the surrounding tile or slate work is checked and made good. Any tiles disturbed during the work are re-bedded or clipped. Broken tiles are replaced. The roof is left as it was found, or better.
Debris from the job - old lead, mortar chippings, tile fragments - is removed from gutters and the surrounding area. Left in the gutter, mortar debris blocks downpipes and causes overflow. A final visual check from ground level confirms the new flashings lie flat and the pointing is consistent along the full run.
We cover Saffron Walden and the wider area stretching to Cambridge, Ely, St Ives and nearby villages. Whether you need a full chimney stack reflash, a dormer abutment repaired, or a flat roof upstand replaced, we carry out every step of the job properly. Call us to arrange an inspection of your roof before any work is agreed.
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Call any time. Calls are answered day and night and passed straight to our roofers.
