If you are arranging lead work on a property in Haverhill, knowing what a well-run job looks like from start to finish helps you judge whether the work is being done properly.
Lead flashing creates the watertight seal where your roof covering meets a vertical surface: a chimney stack, a dormer, a parapet wall, a bay window or a flat roof abutment against a house wall. When lead is fitted correctly and in the right weight of material, it will outlast most of the rest of the roof. When it is poorly installed, it is one of the most common sources of persistent leaks. Good practice is to carry out all lead work by hand-dressing on site to BS EN 12588.
Below is a step-by-step account of what a proper lead work job looks like, from the first look at the roof through to leaving the site clean. Use this as a reference when getting work quoted or when a roofer is on site.
Before any lead is cut or removed, the job starts with a proper survey of the affected area. This means getting onto the roof or, where safe access requires it, using a ladder inspection at close range. Looking from the ground is not sufficient for an accurate diagnosis.
On the survey, the roofer should be checking the condition of the existing lead: whether it is lifting, cracked, or inadequately lapped; whether mortar pointing in the lead chase has failed; whether the underlying timbers or decking are sound; and whether there are secondary problems, such as cracked or slipped tiles around the flashing area, that will need to be dealt with at the same time. A survey that takes less than a few minutes is not thorough enough for a chimney or valley replacement.
The survey should also establish the correct lead code for the application. For step flashings and cover flashings, code 4 (1.80mm) is the typical specification. For valley gutters and back gutters, code 5 (2.24mm) or code 6 (2.65mm) is usually required. If a quote does not specify the lead code, ask before you accept it.
Safe access to the roof needs to be organised before work starts. For most two-storey properties this means a ladder properly footed and secured, or scaffold if the roof is particularly steep or high. Scaffold is slower and more expensive to organise but is sometimes necessary for safety and to allow the roofer to work properly on a wide repair.
Materials and debris from the old flashing should not be dropped loose onto a garden, patio or conservatory below. Tarpaulins or a debris chute are the right approach. Old lead is a valuable scrap material and should be collected and taken away rather than left on site.
The existing lead, mortar and any fixings are removed carefully. On a chimney repair this typically means removing the step flashings working up from the bottom, then lifting any back gutter lead, and finally removing any apron or front gutter detail. Where lead soakers sit beneath slates or tiles, the relevant tiles need to be carefully lifted to get to them.
Once the old lead is out, the mortar chases in the brickwork or stonework are raked clean and inspected. If the chase has deteriorated significantly, it may need to be cut deeper or repaired before new lead can be fitted into it. This is also the point at which any rot or damage in underlying timbers will become visible. On a valley or parapet replacement, the boarding beneath the lead should be inspected in full: wet or soft boards need replacing before the new lead goes down, because lead that sits on a failing substrate will not perform correctly regardless of how well it is dressed.
The surfaces that the new lead will contact need to be clean, sound and correctly prepared. Brickwork chases should be clear of dust and loose material. Timber decking for a valley or flat roof abutment should be dry, structurally sound and free of projecting fixings. Any preservative treatment on new timber should be compatible with lead: some treatments can cause corrosion in contact with lead over time if the materials are not isolated correctly.
On a chimney stack, this is also the point to assess the condition of the pointing and the flaunching (the mortar cap at the top of the stack). Cracks in the flaunching allow water to get into the stack, which can appear as damp on the chimney breast inside. If the flaunching needs attention, it is far more practical to address it while the lead is off than to have a roofer return separately.
This is the skilled core of the job. Lead sheet to the correct code is cut to the required bay lengths. For step flashing, each individual step is cut and dressed to sit cleanly against the tile or slate profile and lap correctly with the soaker beneath it. A step that does not fit the tile profile properly will not shed water reliably.
Lead soakers, where required, are cut to fit between each course of tiles or slates, turned up against the wall face, and set in place before the tiles are relaid. The step flashing then overlaps the soakers to create a two-part weathering detail. This two-piece system is the correct approach for most pitched roof abutments: a one-piece flashing that does both jobs is a shortcut that does not perform as well.
All lead bays must be laid to the correct lengths to manage thermal movement. The maximum bay length for code 4 lead in a standard cover flashing is 1.5 metres. Longer bays expand and contract too much, causing fatigue cracks to develop at the joints. A roofer who runs a single long sheet of lead across a wide chimney or a long valley without bay joints is not working to the correct standard.
Back gutters and valley gutters are dressed to the correct fall so that water runs away freely. A gutter with no fall, or one that holds standing water, will eventually leak regardless of the quality of the lead itself.
Once the lead is dressed and in place, the top edge of the flashing is pushed firmly into the mortar chase and secured. In older properties with lime mortar, a matching lime-based mix is the appropriate pointing material: hard cement will not flex with the movement of the lead and will crack. Where a flexible sealant is used instead of mortar pointing, it should be a non-setting compound designed for the purpose, not general-purpose silicone.
Lead clips or tingles secure the lower edges of flashings in exposed positions to prevent them lifting in wind. This fixing detail is sometimes omitted on a hurried job, and its absence is one reason why flashings lift prematurely.
Any tiles or slates that were lifted to access soakers are relaid and checked. Broken or slipped tiles found during the work should be replaced at this stage. The finished lead surface should be visually checked for correct laps, tight pointing and secure fixing at all edges. Any debris from the work, including old lead, broken tile fragments and mortar dust, should be cleared from the roof surface, the gutters and the ground below.
A well-specified quote should tell you the lead code being used, whether soakers are included, how the lead will be pointed in, and what will happen to any damaged tiles found during the work. If a quote is vague on any of these points, ask before you accept it.
For a survey and quote on lead work at your Haverhill property, call Newmarket Roofers and we will walk through the job with you in plain terms.
No obligation · We usually respond within 2 hours
Storm damage, active leak, damaged ridge - we aim to be on-site within 24 hours.
