Ely Roofers carries out lead flashing installation and repair for homeowners in Newmarket, fixing the leaks that damaged or poorly fitted lead work causes.
Lead flashing is the most reliable material for sealing the joints where a roof meets a chimney, a wall, a valley or a flat roof edge. When it is fitted correctly and fixed to British Standard, it can outlast the tiles around it. When it fails, it does so quietly - often for months before water finds its way through to a ceiling. Knowing the warning signs early saves you from a repair bill that doubles once timbers or plasterwork are involved.
The signs that lead work is failing are not always obvious from the ground, but there are things worth checking from inside and out.
Lead is not indestructible. The most common cause of premature failure is using the wrong code - a thinner sheet costs less on the day but splits within a few years. Movement is the other main factor. Lead expands in warm weather and contracts in cold, and if a flashing is dressed in one unbroken length over roughly 1.5 metres without an expansion joint, that repeated movement will crack it. British Standard practice calls for individual bays with laps between them precisely to allow that movement.
Electrolytic corrosion is less well known but worth understanding. Where lead sits directly against certain metals - particularly zinc or bare copper - a slow chemical reaction corrodes the lead at the contact point. The fix is using a separator material between the two. Where lead sits on treated timber, the preservative chemicals in some treatments can also attack the underside of the sheet over time.
Poor original installation is behind a lot of call-outs. Common faults include lead that has been simply hammered flat against brickwork without clips to hold it, flashings bedded straight into soft mortar without lead tacks, soakers missing entirely from step flashings at abutments, and valleys that are too narrow to cope with the volume of water the slope delivers.
A typical chimney has several separate lead components working together: step flashings running up each side, a back gutter behind the stack, a front apron at the base, and sometimes a soaker system beneath the steps. All of these need to be present and properly overlapped. A common fault is finding that a previous repair replaced only the visible front apron while leaving corroded step flashings in place - the repair looks tidy but the leak continues.
The back gutter is the most critical and the most often neglected. Water running down the rear face of the stack collects there before it can drain to the sides. If the gutter has no proper upstand into the brickwork, or if it has been bedded with mortar that has cracked away, every heavy shower puts water directly onto the roof deck behind the stack.
Open valleys - where the lead is visible as a channel between two roof slopes - are straightforward to inspect. Closed valleys, where tiles have been cut and laid over the lead, hide any deterioration until a leak appears. When lead in a closed valley fails, the repair usually means stripping several courses of tiles on both sides to access the sheet underneath. A proper replacement uses code 4 or code 5 sheet, dressed to the correct width with adequate upstands on each side, and laid in bays with proper laps.
Whether you are getting a repair or a full replacement, a few questions are worth raising with any roofer before work begins.
These are not trick questions - any competent roofer will answer them without hesitation. If the answer to any of them is vague, that tells you something.
If you have a damp patch, a stained ceiling, or lead that has visibly lifted, call us for a roof survey so we can tell you exactly what needs doing.
No obligation · We usually respond within 2 hours
Storm damage, active leak, damaged ridge - we aim to be on-site within 24 hours.
