Lead Work in Watton

Expert Lead Work
in Watton

What lead work does and why it fails

Lead seals the joints where your roof meets something else - a chimney, a wall, a skylight or the valley between two slopes. Tiles and slates shed rain across their surface, but at every junction the geometry changes and water needs a formed metal detail to guide it away. That is the job of lead flashing. When it works correctly, it is one of the most durable parts of a roof. When it fails, the result is a leak that can be difficult to trace and, if left, damaging to the timbers beneath.

Lead fails for several reasons: thermal fatigue (the metal cracks after years of expanding and contracting), corrosion from lime in mortar, impact damage, or poor original installation where sections were run too long, fixed with the wrong materials, or specified at too thin a gauge for the application. In each case, the question for a homeowner is the same: is this a repair job or does the lead need replacing entirely?

Repair or replace - how to decide on lead work in Watton

This is the most useful question to ask when your roofer gets up on the roof, and the answer should be based on the actual condition of the existing lead, not a preference for the bigger job. Here is how to think through it.

When a lead repair makes sense

A repair is appropriate when the existing lead is still fundamentally sound but has failed at a specific, limited point. Typical candidates include:

• A single crack or split in otherwise supple, unfatigued lead, where the surrounding material is still flexible and properly secured
• A pointing failure at the top edge of a stepped flashing, where the lead itself is intact but the mortar holding the wedges has dropped out, allowing the top edge to lift
• A loose section where the lead wedges have corroded or been disturbed, but the lead sheet is still in good condition
• A small apron or soaker that has shifted slightly but has not split

In these cases, a targeted repair - re-pointing the joints, re-wedging the flashing or patching a small crack with a properly lapped lead patch - is a reasonable and cost-effective solution. A patch repair done correctly, with a proper lead-to-lead lapped joint rather than sealant slapped over a crack, can extend the life of an otherwise good piece of lead by a number of years.

A single repair to a lifted or displaced chimney flashing where the lead is otherwise intact might cost in the region of £150-£350, depending on how much access work is involved and whether the chimney mortar joints also need attention.

When lead needs replacing, not repairing

Full replacement is needed when the lead has reached the end of its serviceable life across a wider area, or when a repair would be a short-term fix on material that will fail again soon. Replace rather than repair when:

• The lead is cracked in multiple places or shows a network of fine cracks, which indicates the metal has fatigued throughout and will not hold a patch reliably
• The lead was originally installed in sections that are too long (more than about 1.5 metres without a correctly lapped joint), causing repeated cracking at the same points
• The lead has been coated in bitumen or sealant products in the past, which stiffens the metal and prevents the natural movement it needs - this type of lead tends to crack beneath the coating and the coating itself eventually fails
• The lead is very thin (Code 3 used where Code 4 or 5 was needed) and has worn through
• There has been water ingress long enough to damage the timber beneath, which means the area needs to be opened up fully anyway
• The original installation was so poor - wrong code, wrong fixing method, no soakers where they were needed - that repairing sections would leave other weak points that will leak shortly after

Replacing a full chimney flash on a typical two-storey house in this area costs in the region of £400-£900. A valley re-lead, where the channel between two roof slopes is stripped and new lead is laid over timber boarding, typically runs £500-£1,200 depending on the length and the pitch of the roof. If scaffold is needed for safe access, that adds to the cost but should be explained to you before work starts.

The trap of a partial repair on failing lead

The most common situation where repairs go wrong is when a contractor patches cracked lead that has thermally fatigued across its whole length. The patch holds at the repair point but the lead cracks again a short distance away within a season or two. If a roofer proposes to patch lead that is visibly cracked in several places or that has been patched before and leaked again, it is worth asking directly: in your professional opinion, will this repair last, or will the lead need replacing within a year or two regardless? A straight answer to that question tells you a great deal.

What full lead replacement involves

For a chimney re-flash, the old lead is stripped completely and the mortar holding the wedges is raked out. Any brickwork that has deteriorated is repointed before new lead goes on. New lead is cut and shaped to the correct profile, in sections no longer than around 1.5 metres, with proper lapped joints. Soakers are slipped individually under the tile courses on the up-slope sides of the chimney before the stepped flashing is laid over them. The front apron is fitted and dressed down onto the tiles below. The back gutter, where there is one, is shaped to direct water away from the rear of the stack. All fixing is done with lead wedges into repointed mortar joints, not sealant.

The finished work should look neat and flat, with no proud edges and no exposed sealant over the top. It should be possible to ask the contractor to show you the soakers before the tiles are re-laid, and to explain which code of lead they have used and why.

Signs you need to have your lead work looked at

A damp patch on a chimney breast wall, returning after rain, is the most direct sign. Ceiling staining near a roof window or at a point directly below a valley also suggests a lead detail has failed. Cracking, lifting or a white powdery deposit visible on the lead from the ground indicates weathering that is worth investigating. Moss and debris trapped in a valley can accelerate lead wear and is worth clearing away to see what is underneath.

Areas we cover around Watton

We serve Watton and the surrounding area.

Get a proper assessment of your lead work in Watton

If you have a leak near a chimney, valley or roof junction and you are not sure whether repair or replacement is the right answer, call Thetford Roofers and ask for a roof survey. We will get on the roof, look at the actual condition of the lead and give you a straight assessment and a specific price before any work starts.