If you have a roof leak near a chimney, skylight, or valley in Brundall, failed lead work is the most likely cause.
Lead work covers every joint and transition point on a roof where two surfaces meet or where a structure breaks through the roof covering. Flashings sit at the base of chimney stacks, around soil pipes and roof windows, and along the junction between a roof slope and a party wall. Valleys channel rainwater from the angle where two roof pitches meet. Soakers are small interlocking pieces of lead that slot between individual slates or tiles and a vertical surface, hidden behind the step flashing above them. Without these components doing their job properly, water finds its way in.
Lead has been used on British roofs for centuries because nothing else handles movement, heat expansion, and complex shapes quite as well. A well-executed lead flashing, dressed properly into a raked mortar joint and dressed down over the tile surface, will outlast almost every other roofing material on the building. Poor lead work, by contrast, fails quickly and silently, often dripping into a ceiling long before the damage is obvious.
The most common cause of flashing failure is movement. Lead expands and contracts significantly with temperature changes. Flashings that are fixed too rigidly, or laid in single lengths that are too long, develop cracks at the fixing points over time. Correctly installed flashings are fixed in individual bays no longer than 1.5 metres, with movement joints built in so the lead can breathe without tearing itself apart.
A second common cause is poor pointing. Lead is tucked into a raked mortar joint and held with lead wedges, then pointed over with mortar or a proprietary sealant. When that pointing cracks and falls out, the top edge of the flashing lifts in the wind and water gets behind it. This is often misdiagnosed as a slipped tile when the real problem is the flashing itself.
Old lead also hardens and becomes brittle over time. Lead that was laid fifty or more years ago may look intact but crack when pressed. Patching brittle lead rarely holds well. At that age, replacement is usually the more sensible option.
A further issue is incorrect code. Lead is graded by thickness, described as a code number from 3 to 8. The code needed depends on where the lead is being used. Soakers are typically code 3 or 4. Back gutters behind chimney stacks need code 5 or heavier. Flat roof coverings and parapet gutters need code 5 or 6 as a minimum. Using underweight lead to cut costs is a false economy; it simply will not last.
This is the section most homeowners rarely get a clear answer on, so it is worth going through each option honestly.
Milled lead sheet is the benchmark material. It is dense, malleable, and proven over generations. A back gutter in code 5 milled lead, properly installed, can realistically last 60 to 100 years. It can be worked by hand around complex shapes - the curved base of a chimney, the awkward angle where a dormer meets the main slope - in a way that pre-formed products simply cannot match.
The downside is cost and weight. Lead is a commodity metal and its price moves with the market. At current prices, lead work on a standard chimney stack with four-piece flashing set typically costs in the region of £400 to £800 depending on the size of the stack, access difficulty, and how much mortar work is involved. A valley re-lead on a semi-detached house runs from around £600 to £1,500 or more for a long valley with complex junctions. These are not small sums, but the material genuinely earns its price through longevity.
Weight is relevant on older structures. Lead on a flat roof area adds significant load. On a solid Victorian brick parapet this is rarely a concern, but on a modern lightweight flat roof extension the structural implications should be considered before specifying the heaviest code lead.
Soakers are rarely seen because they sit underneath the tiles or slates, but they are critical. Each soaker wraps around the base of an individual slate or tile and tucks behind the flashing above. When they fail, water runs straight down the junction between the roof slope and the wall. Code 3 is the minimum for soakers; code 4 gives a longer service life for not much extra cost and is worth asking for when the roof is being stripped for a full re-slate anyway.
Several alternative products now exist that are marketed as substitutes for lead flashings. The two most widely available are aluminium-faced self-adhesive flashing tape and purpose-made lead-free flashing products made from polymers or composite materials. They are worth understanding clearly, because not all are equal and some roofers use them where they are not appropriate.
Self-adhesive flashing tape (sometimes sold under brand names) is a bitumen-based tape with an aluminium or mineral face. It is fast to apply and useful for emergency temporary repairs or for sealing around small penetrations on flat roofs. Its limitations are significant: the adhesive bond degrades over time, particularly on dirty or damp surfaces; it cannot be pointed into a mortar joint; and it has no real structural integrity in the way that code lead does. On a chimney stack exposed to wet weather, tape is a short-term measure. A competent roofer will tell you this upfront.
Lead-free composite flashings are a more serious product. Some of these are polymer-based rolls that can be cut, formed, and fixed much like lead, without the weight penalty. They are lighter, easier to handle at height, and do not carry the theft risk that lead does (lead theft from roofs is a real problem, particularly on churches and older properties). Some products in this category carry manufacturer guarantees of 25 years or more. However, composite flashings are not as workable as lead around complex shapes, and their long-term field performance in UK conditions is not as well established as milled lead, which has a track record measured in generations rather than decades.
For most standard flashings on a pitched roof, traditional milled lead remains the best choice for long-term performance. For large flat roof areas where weight is a concern, or for properties in areas with a history of metal theft, discussing alternatives is reasonable. The key question to ask any roofer is: what code or specification are you using, and why is that appropriate for this location?
Where lead is being considered for a small flat roof area or a parapet gutter, EPDM rubber sheet is worth considering alongside it. EPDM is a single-ply synthetic rubber membrane that handles flat and low-pitched areas well. It is lighter than lead, flexible in cold weather, and has a good track record in commercial and domestic use in the UK. It does not suit every situation - it cannot replace soakers or be pointed into mortar joints in the way lead can - but for a straightforward flat roof area, it is a legitimate alternative that avoids the weight and cost of heavier code lead. We can advise on which approach suits the specific geometry and condition of your roof.
Before any new lead is fitted, the existing mortar joints need to be raked out cleanly to the correct depth, typically 25 mm. The lead is then cut to length in individual bays, folded at the ends to form proper stop ends, and fixed into the joint with lead wedges at regular intervals. The pointing that goes over it should use a mortar mix appropriate to the age of the building - hard cement mortar on soft old brickwork causes more problems than it solves. On older properties, lime-based pointing or a specialist flashing sealant is often more appropriate.
The lead is then dressed down over the tile or slate surface using a bossing mallet and dresser. The goal is a tight, wrinkle-free fit that sheds water away from the wall without bridging the lap onto the tiles below. Flashings that are dressed too hard and crack, or left too loose and rattle in wind, are signs of rushed work.
For valleys, the old lead is removed, the timber boards beneath are inspected and replaced if rotten, and new code 5 or code 6 lead is laid in bays with proper laps. The valley is then dressed to a tidy, consistent width that allows water to flow freely without overflowing in heavy rain.
After the work is complete, the area should be cleaned down and any disturbed tiles re-bedded or re-nailed as required. It is reasonable to ask the roofer to show you the work before they leave, particularly on chimney stacks where access is limited.
Lead work problems often show themselves inside before the roof is inspected. Damp patches on ceilings near chimneys, at the junction of a flat roof extension and the main wall, or at the foot of a dormer window are all classic signs. Staining that appears after heavy rain and dries out between showers suggests an intermittent flashing failure rather than a burst pipe.
From outside, visible signs include mortar pointing that has dropped out from flashing joints, lead that has lifted or pulled away from the wall, green or white streaking down brickwork from lead corrosion, and any visible gaps between the lead and the surface it should be sealed against.
If a roof has not been inspected for several years, it is worth having the flashings checked as part of any general roof survey, particularly on a chimney stack that is no longer in use. Unused stacks are often not maintained because they are not causing a visible problem yet, but they are still exposed to weather and the flashing deteriorates at the same rate.
A question that comes up is whether roof work, including lead work, adds value to a home. The honest answer is that failed or missing lead work will actively reduce the value a surveyor places on a property and will appear on a homebuyer's report as a defect requiring attention. Buyers' solicitors routinely ask for work like this to be completed before exchange, or for a price reduction to cover it. Rectifying known lead work defects before putting a house on the market is generally worthwhile, as the cost of the repair is almost always less than the reduction a buyer will negotiate.
Good lead work does not add value beyond the baseline expectation that a roof should be weathertight. What it does is remove a liability and give the buyer, and you, confidence that the roof is in sound order.
We carry out lead work across Brundall and the surrounding area. If you are not sure whether we cover your location, call us and we will tell you directly.
When getting quotes for lead work, ask each roofer to specify the lead code they intend to use and why it suits the location. Ask whether soakers are included where the flashing meets a pitched roof slope, and ask what they plan to do with the mortar pointing. A roofer who can answer these questions clearly is one who understands the work. A vague answer about "industry-standard materials" without specifics is worth pressing on.
Ask to see the work before the scaffolding or ladder comes down. Photographs from the roofer are useful but standing on the scaffold yourself and seeing the finished flashings is better if the roofer is willing and it is safe to do so.
For an accurate price, a roofer needs to see the job in person. Photographs help but they cannot show the condition of the mortar joints, the state of the timber beneath a valley, or how much movement there is in an existing flashing. Call us to arrange a visit and we will give you a straight assessment of what needs doing and what it will cost.
No obligation · We usually respond within 2 hours
Storm damage, active leak, damaged ridge - we aim to be on-site within 24 hours.
