Lead Work in Cottenham

Expert Lead Work
in Cottenham

What Lead Work Actually Involves

Lead flashing is the material that seals the joints between your roof covering and any upstanding surface: a chimney, a parapet wall, a dormer, a valley between two roof pitches, or the edge of a flat roof section. When it is correctly installed, lead work is one of the most durable roofing materials available. When it is poorly fitted or starts to fail, it becomes one of the most common causes of persistent water ingress.

Lead flashing should be installed and repaired using code 4 or code 5 lead sheet, dressed and fixed to British Standard. Code 4 (1.8 mm thick) is the standard weight for most stepped and cover flashings. Code 5 (2.24 mm) is heavier and used where greater durability or width is needed, such as in wide chimney back gutters or valley gutters.

Common Lead Work Problems and Why They Happen

The most frequently seen problems are cracked mortar fillets used as a substitute for proper lead flashing, perished or lifted step flashings on chimney stacks, split valley gutters, and poorly lapped sections that allow wind-driven rain to enter. Mortar fillets crack because mortar cannot move with the thermal expansion and contraction of the roof structure. Lead can, which is why it is the correct material for these joints.

A common problem is lead that was bedded into the mortar course too shallowly. The correct minimum is 25 mm of lead tucked into the chase. If the lead has only been pointed over rather than properly dressed in, the joint will fail within a few years regardless of how good the pointing looks on the day.

Thermal movement is another factor. Lead expands and contracts noticeably with temperature. Flashings longer than 1.5 metres must be jointed to allow for this movement. If they are not, the lead will buckle and eventually crack at fixed points. This is a detail that separates a proper installation from a short-cut one.

How to Choose a Lead Work Contractor in Cottenham

The most important thing you can do before agreeing to any lead work is ask specific questions about the job itself. A contractor who cannot answer clearly about lead codes, fixing methods and standards is one who probably does not apply them.

Questions worth asking before you agree

• What code of lead sheet will you use? The answer should be code 4 or code 5 depending on the location. If the contractor does not know what lead codes are, walk away.
• Will the flashing be dressed into a proper mortar chase, or just pointed over? Chasing in and re-pointing is correct. Pointing over existing or improvised fixings is not.
• How will you fix the lead to prevent thermal movement splitting it? Long runs should be jointed every 1.5 metres. Clips or wedges should be used rather than nails alone, which can pull through.
• Will you be doing the work yourself, or sending a labourer? Lead dressing is a skilled trade. It requires judgement about thickness, overlap, fixing depth and the condition of the substrate beneath. A labourer following instructions is not the same as an experienced tradesperson.
• Are you removing the old lead or laying new material over it? Laying new lead over failed old lead is almost always the wrong answer. Old lead can be in poor condition underneath, and the additional weight and thermal movement of two layers creates more problems than it solves. Removal and replacement is the proper approach in most cases.
• What will you do about the masonry? If the flashing is around a chimney, the mortar pointing of the stack itself matters. New flashing against a chimney with failed pointing is a short-term fix. A good contractor will tell you honestly if the brickwork needs attention too.

What a Properly Quoted Lead Work Job Should Include

A quote for lead work should specify the location of the work, the lead code being used, how the lead will be fixed and whether any chase cutting or mortar work is included. Vague quotes that simply say "repair lead flashings" without any of this detail give you no basis for comparison and no recourse if the work is substandard.

Typical costs for lead work in the UK vary considerably by scope. A straightforward chimney flashing repair, where one or two sections of step flashing need dressing back and re-pointing, might cost in the region of £150 to £350. A full chimney re-flash with new code 5 lead all round, including back gutter and apron, is typically £500 to £1,000 or more depending on chimney size and access. Valley replacements in lead are generally priced per linear metre and can run from £100 to £200 per metre or more, depending on the depth and difficulty of the valley. These are honest current UK ranges, not guarantees of what any specific job will cost.

Be cautious of very low quotes. Lead sheet is not cheap, and if the price seems too low to cover both the material and the labour, it probably means a lighter grade of lead is being used, the preparation work is being skipped, or the fixing method will not last.

Red Flags to Watch For

• A contractor who suggests using lead flashing sealant or self-adhesive flashing tape as a permanent fix rather than properly dressed sheet lead. These products have a place as emergency repairs, not long-term solutions.
• Anyone who quotes without getting onto the roof to inspect the existing flashing, the masonry and the underlying timber or structure.
• Pressure to agree on the day without time to compare quotes or ask questions.
• No clear explanation of what code of lead will be used or why.

Lead Work Across the Ely Area

Lead work should be carried out to the same British Standard specification on every job. Whether you have a single failed chimney flashing or a full valley replacement, call us for a roof survey so we can tell you honestly what the job involves before you commit to anything.