Lead Work in Little Shelford

Expert Lead Work
in Little Shelford

What Lead Work Actually Involves

Lead flashings seal the joints between your roof covering and any vertical surface that breaks through or meets it. Chimneys, dormer cheeks, parapet walls, and flat roof abutments all rely on correctly cut and dressed lead to keep water out. When lead fails, water tracks silently down into the roof structure before you ever see a stain on the ceiling.

Good lead work is not just a matter of cutting a piece of metal to shape and wedging it in. The lead must be the correct Code for the application, fixed with the right clips, dressed into mortar joints at the correct depth, and allowed room to expand with changes in temperature. Every one of those details matters for a joint that will last.

Lead Codes and Why They Matter

Lead sheet is graded by thickness, described as a Code number. Code 3 (1.32mm) is the thinnest and is sometimes used for small soakers. Code 4 (1.80mm) is standard for step and cover flashings. Code 5 (2.24mm) is used on wider gutter linings and flat roof upstands. Code 6 (2.65mm) suits wide or exposed applications. Using too thin a Code is a common false economy that leads to splitting and lifting within a few years.

When asking a contractor what they plan to use, expect a specific answer, not a vague reference to "the right lead". If they cannot tell you the Code for each part of the job, that is worth knowing before you agree to anything.

How to Choose a Lead Work Contractor in Little Shelford

Plenty of general builders will offer to re-bed a flashing or seal a joint with mastic. That is not the same as proper lead work. Below are the questions worth asking before you let anyone on your roof.

• Do you cut and dress lead on site? Genuine lead work means cutting sheets to the profile of your chimney or dormer and dressing them down with a bossing mallet or a lead dresser. Pre-formed flashings are sometimes used for straightforward work, but bespoke dressing is what a difficult junction needs.
• What Code will you use? As above. A contractor who knows their work will answer without hesitation.
• How will the lead be fixed and how will expansion be managed? Lead moves with heat. Sheets longer than about 1.5 metres need separate pieces with drips or laps between them to allow for movement. Fixing lead in one continuous run on a long abutment is a known cause of splitting.
• Will you re-point the mortar joints once the lead is in? Step flashings are tucked into raked mortar joints in the brickwork, then pointed up afterwards. If the mortar is left loose or is pointed with the wrong mix, the lead will pull free in a few years.
• What happens to the surrounding tiles or slates? Lifting and relaying slates to fit new soakers takes time. Ask whether this is included and whether any broken slates will be replaced.
• Can you show me an example of completed lead work? A photo of a recently finished chimney or dormer is a reasonable thing to ask for. If the contractor cannot or will not show you one, that tells you something.

Red Flags to Watch For

Mastic or sealant applied over or instead of lead is almost always a temporary measure that disguises the problem rather than solving it. Some contractors use it as a quick fix on a job they are not confident doing properly. Sealant can hold for a season or two before shrinking and cracking, at which point water is back in and the lead still needs replacing.

Torch-on felt lapped over old lead at a chimney base is another patch that turns into a larger job later. The felt separates from the lead as the chimney moves and the roof deck expands. Proper lead work at the base of a chimney, with soakers between each slate course and a cover flashing that can be removed and re-dressed without stripping the roof, is the correct approach.

Be cautious of any quote that does not mention what Code of lead will be used or that does not explain how the lead will be secured to the brickwork. A good contractor will explain the job to you in plain terms before they start.

What to Expect from the Work Itself

A typical chimney re-flash on a standard semi-detached house involves removing the old lead, raking out the mortar joints, cutting and dressing new step flashings and a back gutter or saddle at the top of the chimney, bedding soakers between the slate or tile courses, and pointing up once everything is in place.

A dormer cheek or a flat roof abutment is quicker if the surface is in good order, but can take longer if the surrounding felt or tile needs attention at the same time. It is worth asking the contractor to look at the whole junction, not just the part that is obviously leaking.

Typical Costs

Lead work is priced by the job rather than by a simple rate, but as a rough guide, re-flashing a chimney on a standard house typically costs somewhere between £400 and £900 depending on the size of the stack and how much access work is needed. Dormer side flashings are often in the £200 to £500 range. Flat roof upstand and abutment work varies widely depending on the length of the run and the condition of the surrounding structure. Always get the quote to specify the Code of lead and what surface preparation is included.

Cambridge Roofers Covering Little Shelford

We cut and dress lead to the correct Code for each application. If you can see daylight between the lead and the brickwork, or you have had a damp patch appear on a ceiling below a chimney or dormer, call us for a roof survey so we can tell you exactly what needs doing and why.