How long should lead flashing last?

Correctly specified and fixed lead commonly lasts many decades — often longer than the roof covering. Premature failure is nearly always a specification or fixing fault rather than the material.

Can lead flashing be repaired or does it need replacing?

Small splits can sometimes be lead-welded, but if the lead has split because the bay is too long or the code too thin, patching only delays the next failure. Reforming the detail correctly is the durable answer.

Are there alternatives to lead?

Flexible flashing tapes and proprietary alternatives exist and are useful in some situations, but on traditional and conservation-area buildings lead remains the correct and expected material.

Why is there white staining on the wall under my new flashing?

That is lead carbonate washing off new lead that has not been treated with patination oil. It is preventable at installation.

Roofing service

Leadwork and Lead Flashing in Carlisle and Cumbria

Leadwork is the formed metal detailing that waterproofs the junctions of a roof — chimney flashings, valleys, soakers, box gutters, dormer cheeks and parapet linings. Correctly sized and fixed lead outlasts almost every other component on a roof.

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Close-up of newly dressed code-rated lead flashing and a lead-lined valley between two roof slopes, wet after rain

Leadwork in Carlisle and across Cumbria

Roofs rarely leak in the middle of a slope. They leak where the roof meets something else: a wall, a chimney, a valley, a dormer or a parapet. Those junctions are waterproofed with lead, and the quality of that leadwork decides whether the roof stays dry.

Lead moves considerably with temperature. That is why bay lengths, fixings and laps are specified rather than improvised — lead that is too long or rigidly fixed will crack along a fold within a few years.

When to call us

Leaks where a roof abuts a wall or chimney
Cracked or split lead along a fold line
Lead lifted out of the mortar joint by wind
Cement fillets used in place of lead flashings
Failed valley linings on slate and tile roofs
Box gutters and parapet gutters overflowing or leaking
Dormer cheeks and window head details letting water in
Lead sheet that is undersized for the detail

How we approach it

Very long service life

Lead installed to correct codes and bay lengths regularly outlasts the roof covering around it.

Correct codes and bay sizes

Lead thickness and sheet length are specified for the detail and the exposure, which is what prevents thermal splitting.

Mechanically fixed, not glued

Flashings are chased into the joint, wedged and pointed, and clipped at the free edge rather than relying on sealant.

Right for period buildings

Traditional lead detailing is appropriate for listed and conservation-area properties where modern alternatives are not.

What happens, step by step

1. Identify the detail
We establish exactly which junction is failing and why — code too thin, bay too long, no clip, or no lead at all.
2. Specify the lead
Code, bay length, lap, upstand height and fixing method are set for the detail and the exposure of the building.
3. Strip out the old detail
Failed lead or cracked cement fillets are removed and the masonry joint is raked out ready for the new flashing.
4. Form and fix
Lead is dressed on site, chased into the joint, wedged, pointed and clipped, with soakers interleaved with the slates or tiles.
5. Make good and check
Surrounding covering is reinstated, the work is photographed and the detail is checked under water where practical.

Properties we work on

Properties with chimney stacks passing through the roof
Houses with valleys between roof slopes
Dormer windows and dormer bungalows
Buildings with parapet walls and box gutters
Extensions abutting a main wall
Bay window and porch roofs
Traditional stone buildings and listed properties

Materials and systems we use

Code 4 lead: Typically used for soakers and smaller flashings on domestic pitched roofs.
Code 5 lead: Used for step and apron flashings, valley linings and more exposed details.
Code 6 and above: Specified for box gutters, parapet gutters and larger areas where greater durability is required.
Patination oil: Applied to new lead to prevent the white carbonate staining that otherwise washes down onto the wall below.
Lead wedges and clips: Mechanical fixings that hold the flashing in the joint and restrain the free edge against wind.

Mistakes and shortcuts to avoid

Bay lengths that are too long

Over-long lead cannot expand and contract freely and splits along the fold. Bay length limits exist for a reason.

Sealant instead of a chase

Lead stuck to a wall with mastic will release. It must be turned into a raked joint, wedged and pointed.

Undersized lead

Thin lead used on a big detail fatigues quickly and cracks, particularly on south-facing elevations.

No patination oil on new work

Untreated new lead stains the masonry beneath it white, which is unsightly and difficult to remove.

Leadwork: common questions

Where we carry out this work

We are based in Carlisle and cover the city, the wider county and across the border into South West Scotland.

Roof Leaks & DampTracing water back to where it actually gets in, separating roof leaks from condensation and rainwater goods, and confirming the cause before paying for a repair.