Lead Work in Godmanchester

Expert Lead Work
in Godmanchester

What Lead Flashings Are and Why They Fail

Lead flashings are the strips of dressed lead that seal the junctions between your roof and any vertical surface it meets: a chimney stack, a dormer, a parapet wall, or the edge of a flat roof where it meets a house wall. These junctions are where most roof leaks originate, because they are where two different building surfaces meet and move at different rates with temperature and settlement.

A correctly installed flashing, cut and dressed to the right Code thickness, is one of the most durable elements of a domestic roof. The failures that cause leaks are almost always down to poor original installation, the wrong Code of lead being used, fixings that have corroded or pulled out, or mortar pointing that has cracked open and let the lead drop away from the wall. Lead itself, at the correct specification, does not suddenly fail without a reason.

What to Do While You Wait for a Roofer

If you have an active leak through a flashing, there are a few things you can do immediately to limit the damage while you arrange a proper inspection.

• Put a bucket or container under any drip. Obvious, but the priority is catching water before it soaks into a ceiling, floor or stored contents. A damp ceiling that is kept dry overhead is much easier and cheaper to repair than one that has absorbed water for days.
• Protect what's below. Move furniture, electronics and anything else vulnerable away from the drip area. If the drip is into a ceiling void, resist the urge to poke a hole in the plasterboard to drain it; a ceiling that has already bowed with water can collapse with little warning, and creating a hole in the wrong place can let a larger volume drop at once.
• Take photographs from ground level or a window. Photos of where the drip is entering inside, and any visible damage to flashings from ground level, are genuinely useful to the roofer when they arrive. They help narrow down the likely source and confirm whether the damage you can see from outside matches the internal leak location.
• Check whether the water is tracking. Water entering through a failed flashing often travels along a rafter or roof timber before dripping, which means the internal drip point can be some distance from the actual entry point. Knowing roughly where on the roof the flashing problem is helps the roofer focus the inspection correctly.
• Note whether the leak is worse during or after heavy rain, or whether it appears even in dry weather. If a chimney breast shows damp only during rain, the cause is almost certainly the flashings or the pot. If it's damp regardless of weather, condensation within the flue may be the issue rather than the lead work. This distinction changes the repair.

What Not to Do Yourself

This is important. The instinct to deal with a leak yourself is understandable, but the wrong intervention makes the eventual proper repair harder and more expensive.

• Do not apply mastic or roofing sealant to a lifted flashing. Sealant applied over a gap in a lead flashing traps moisture behind the lead, accelerates corrosion of fixings, and bonds to the masonry in a way that makes removing it before the proper repair a significant additional job. It also typically holds for one season at most before the thermal movement of the lead breaks the seal again.
• Do not push a lifted section of lead back by hand. Without re-fixing the clip and re-pointing the mortar chase, it will lift again at the first frost. If the lead has been displaced significantly, re-dressing it without the correct tools can crack it, converting a repairable lift into a replacement job.
• Do not attempt to repoint the chase yourself. The mortar mix and technique used to seal lead into a chase is specific. Too hard a mortar doesn't flex with the lead's movement and cracks open quickly. The wrong mix will fail faster than the original.
• Do not go onto the roof. Pitched roofs are dangerous without the correct equipment and footwear. Flat roof surfaces can be damaged by foot traffic in the wrong place, which worsens the problem. Leave the inspection to a roofer with the right access equipment.

What to Expect When a Roofer Inspects the Lead Work

A thorough lead work inspection goes further than confirming that a flashing has lifted. A good roofer will check the condition of the lead itself to determine whether repair or full replacement is the right call. They will look at the Code of lead that was used (too thin a lead is a common cause of repeated failure), the condition of the mortar pointing in the chase, the fixings, and the surrounding roof materials.

On a chimney specifically, there are four elements of lead work: the front apron below the stack, the two sets of stepped flashings up the sides, and the back gutter behind the stack at the top. All four need to be in sound condition for the chimney to be watertight. A roofer who inspects only the visible front and sides without checking the back gutter is not doing a complete job.

You should expect the roofer to explain what they have found, what needs doing, and why, before any work begins. If an explanation isn't offered, ask for one. Understanding what Code of lead is being used, how the fixings will work, and how the chase will be finished is reasonable and any competent contractor should be able to answer all three questions clearly.

Typical Costs for Lead Work

Lead work on a standard chimney in Cambridgeshire typically falls in the range of £300 to £700, depending on the size of the stack and the number of elements involved. A full re-lead of a larger stack with a proper back gutter will be at the upper end or beyond. Repairs to a single lifted or cracked section where the lead itself is sound often cost in the range of £150 to £300. Any quote should itemise what is included; a single total with no breakdown makes it impossible to check what you are actually paying for.

What the Repair or Replacement Actually Involves

Where lead is being replaced, the old material is stripped, the chase is cleaned out and re-cut if necessary, and new lead of the correct Code is cut and dressed to fit the geometry of your specific chimney, dormer or abutment. Lead is a hand-worked material; a roofer cuts and dresses each section on site. Lead clips are fitted at the right intervals to allow the lead to expand and contract without cracking. The top edge is then pressed into the chase and pointed with an appropriate mortar to hold it in place and shed water.

On flat roof sections, a lead upstand at a wall abutment needs to turn up against the wall to a minimum of 150mm above the roof surface. If the existing upstand is lower than this, water blown in rain or pooling against the wall can get behind it. This is one of the most frequently skipped details on flat roof lead work.

Lead Work on Different Roof Types

Lead flashings are used across slate roofs, plain clay tile roofs, and concrete tile roofs. The detailing differs: on natural slate, individual soakers are cut and fitted under each course alongside the step flashing; on profiled concrete tiles the soaker dimensions change to account for the tile's profile. Lead is also used at parapets, alongside felt and EPDM rubber flat roof systems, and occasionally on zinc or copper-clad sections where the materials need to be properly integrated.

Cambridge Roofers Cover Godmanchester and the Surrounding Area

We work on lead flashings for homeowners in Godmanchester and nearby, including St Ives, Cambridge, and surrounding villages across Cambridgeshire. If you have an active leak or you want a proper inspection of flashings that are starting to look suspect, call us to arrange a roof survey before the problem gets into the structure.