Lead Work in Aylsham

How we handle lead work

Lead Work in Aylsham and Across North Norfolk

Lead flashing and lead work is the craft of shaping and fixing sheet lead to the vulnerable joints on a roof - the places where two surfaces meet, where a chimney stack rises through the slope, or where a roof meets a wall. When that lead fails, water gets in. It is rarely a dramatic flood; more often it is a slow, creeping damp that works its way into the roof structure, ceiling timbers and plasterwork before anyone notices. Sorting it early is nearly always cheaper than waiting.

Homeowners in Aylsham and the surrounding villages often discover lead problems when a damp patch appears on an upstairs ceiling or when they notice the mortar that was holding flashing in place has crumbled away. That mortar joint, called a raggle or a chase, is one of the first things we check. If the lead itself is sound but the pointing has gone, the fix is straightforward. If the lead is cracked, thin or has been lifted by frost, it usually needs replacing.

Where Lead Is Used on a Roof

Lead appears in several places on a typical North Norfolk property, and each location presents its own demands:

• Chimney flashings - the most common source of lead-related leaks. A chimney has a step flashing up each side, a back gutter behind it and an apron at the front. All four pieces need to be correctly dressed and pointed to stay watertight.
• Valley gutters - the channel formed where two roof slopes meet. In older properties these are often lined with lead, and the channel can crack or split as the lead moves with temperature changes over many years.
• Abutment flashings - where a lean-to, side extension or flat roof meets a main house wall. A common problem here is flashing that was tucked rather than chased into the mortar, which eventually pulls away.
• Dormers - the cheeks and sills of dormer windows need carefully dressed lead to stop water tracking in at the edges.
• Parapet walls - the capping lead on a parapet must be jointed and dressed correctly so that rainwater drains towards the roof rather than pooling and soaking into the brickwork below.
• Flat roof upstands - where a felt or EPDM flat roof meets a vertical surface, a lead flashing provides the final weathertight seal at the top edge.

What Good Lead Work Actually Involves

Sheet lead comes in different thicknesses, measured as "codes" from Code 3 up to Code 8. The right code for each location matters. Chimney back gutters and valley gutters need Code 5 or Code 6 lead to handle the volume of water and to resist the movement caused by thermal expansion. Aprons and step flashings are typically Code 4 or Code 5. Using undersized lead to save money is a false economy - thin lead cracks under repeated expansion and contraction cycles.

Each piece of lead is cut to length and dressed by hand using a bossing mallet or a lead dresser to form tight, neat angles at corners and junctions. On a chimney, the step flashings are cut in a series of overlapping sections, each tucked into a raked mortar joint and secured with a lead wedge before the joint is repointed with mortar. Cutting every section to the right size and keeping the overlaps correct is skilled, unhurried work. Rushed or careless lead work leaves gaps where water can track behind the flashing during driving rain.

Expansion is something that catches out poor lead work. Lead moves considerably as it heats and cools. Individual pieces should not exceed around 1.5 metres in length for most applications, and each piece needs enough freedom to move without tearing at its fixing points. On valley gutters, rolls or drips are formed across the sheet at regular intervals to allow movement. If a previous installer ignored this, the lead can split at the fixing points over time, and that split is where the leak begins.

Chimney Lead Work - the Detail That Matters

Chimney stacks take a particular battering from wind and frost. The mortar between the bricks weathers faster than the bricks themselves, and as the mortar in the chase degrades, it allows the flashing to loosen and lift. Once lifted, even briefly, water can enter the roof void with every rain shower.

A thorough chimney lead job involves removing the old flashing, raking out the mortar chases to a good depth (typically 25 mm or more), dressing new lead into those chases, wedging it firmly, and repointing with a suitable mortar. The lead apron at the front is dressed down over the tiles or slates, and the back gutter is formed to direct water out to either side rather than pooling. On a wide chimney, a saddle or cricket is sometimes built on the high side to divert water around the stack rather than letting it collect behind it.

If there are signs of moss or debris collecting in the back gutter area, that is worth clearing at the same time. Blocked gutters behind a chimney cause water to back up under the flashing, and the problem is often mistaken for failed flashing when the lead itself is actually sound.

Valley Lead Work

An open lead valley is a traditional and durable way to handle the junction between two roof slopes, provided it is installed correctly. The valley boards beneath the lead need to be sound and continuous - gaps or splits in the boarding allow the lead to flex and split. The lead is laid in sections, each overlapping the one below by at least 150 mm, and rolls are formed at each joint to allow thermal movement.

A common problem in older Norfolk properties is a valley that was originally built wide enough but has been narrowed over the years by poorly trimmed tiles or slates encroaching on the channel. Restricted valleys hold debris and slow drainage, which can cause water to back up in heavy rain. Cutting back the tiles to restore the correct channel width is often part of a proper valley repair.

Lead valleys can also be affected by the mortar haunching that is sometimes used to bed the tiles at the valley edge. When that haunching cracks, it traps water against the lead rather than shedding it cleanly. Repointing or re-bedding the valley tiles is sometimes needed alongside the lead work itself.

Repair or Full Replacement - How to Tell

Not all lead problems require a full strip and relay. If flashing has lifted at one point because a mortar chase has failed but the lead itself is in reasonable condition, re-chasing and repointing can be sufficient. Lead that has been in place for 50 or 60 years on a well-built roof is often still serviceable if it has the right thickness and has not cracked.

Signs that replacement is more appropriate than repair include:

• Multiple splits or cracks across the surface of the lead, particularly at bends and corners
• Lead that has become very thin in places due to corrosion or previous patching
• Patching that has been applied over older patching - a sign that repair work has been repeated without addressing the underlying cause
• Lead that has pulled away from the chase in several places and can no longer be re-wedged securely
• Valley lead that has split along its length due to inadequate provision for movement

A proper inspection of the lead work should always precede a decision about repair versus replacement. If you are not sure which situation you are in, it is worth getting someone to take a look rather than guessing from the ground.

What Lead Work Costs in Aylsham

Lead work is priced by the job rather than by a single rate, because the amount of lead, the complexity of the detailing and the access required vary considerably. As a general guide, chimney flashing repairs in Norfolk typically cost between £200 and £600 for a straightforward stack, rising to £800 or more where a chimney is wide, has multiple flue pots or requires new lead throughout. Valley lead replacement on a standard domestic roof runs from around £400 to £900 or more depending on the length of the valley and the condition of the underlying boarding. Full chimney lead replacement - apron, two sides of step flashing and back gutter - on a typical two-storey property generally falls in the range of £500 to £1,200. These are typical UK ranges; the actual cost depends on the specific job, the access required and what is found once the old lead is removed.

Working Across North Norfolk

The properties we work on across this part of Norfolk vary considerably in age and style.

Brick and flint construction is common across this part of North Norfolk, and the flint work can make access to chimney flashings more difficult than on a plain brick wall. It also means that repointing after lead work needs to match the original bedding mortar in strength and composition - a hard cement mortar can crack adjacent pointing and let in more water than it keeps out.

Getting a Survey and Quote

If you have a damp patch near a chimney or a roof junction, or if you can see from the ground that flashing has pulled away from the wall, give us a call to arrange a proper inspection. We will tell you honestly what needs doing and what can wait. A small lead repair carried out promptly typically costs a fraction of the ceiling repair and redecoration that follows if it is left.

Lead flashing on a correctly built chimney, fitted with the right code of lead and properly pointed, can remain watertight for 50 years or more. The key is getting the initial work done correctly and using lead of the right weight for the application. Call us to book a roof survey and we will confirm exactly what your roof needs.