Lead is the most durable roofing material available — properly installed it outlasts the building. We repair and replace lead flat roofs, bay tops, dormers, valleys and flashings across Farnham using Code 4 and Code 5 milled lead sheet to BS EN 12588 standards.
From lead flat roofs and bay tops to flashing repairs and valley replacements, we carry out all lead roofing work to recognised industry standards across the Farnham area.
New lead flat roofs for bay tops, dormers, extensions and porches. Code 4 lead sheet with proper drip edges, welted seams and adequate expansion joints for the Surrey climate.
From £800Step, soaker, apron and saddle flashings around chimneys, dormers, walls and skylights. The most common cause of roof leaks on Farnham's period properties.
From £200Lead valley replacement on pitched roofs. We strip failed lead or mortar valleys and install new lead to the correct code for the pitch and exposure of your roof.
From £400Splits, lifting edges, failed joints and cracking from thermal movement. Many lead defects can be repaired rather than replaced if caught early — saving significant cost.
From £150Lead expands and contracts significantly with temperature. Sheets fixed too rigidly split at fixings. Correct installation includes expansion gaps sized to the sheet dimensions.
Lead sheets worked too hard by repeated thermal cycling develop fatigue cracks — usually at bays or rolls. Most common on older bay top roofs with large unsupported sheets.
Flat lead roofs need a minimum fall to drain. Ponding water on a flat lead roof accelerates oxidation and stresses seams. We re-profile the deck when relaying if required.
Lead flashings that are pointed rather than wedged and sealed into mortar joints fail when the mortar shrinks. The correct fix is to chase, wedge and seal — not re-point over the top.
| Job Type | Typical Cost | Notes |
|---|---|---|
| Chimney flashing repair / replace | £200–£600 | Step, apron and saddle |
| Bay top lead replacement (small) | £600–£1,200 | Code 4 lead, new deck if required |
| Bay top lead replacement (large) | £1,000–£2,000 | Code 5 lead, welted seams |
| Lead valley replacement (per metre) | £150–£300/m | Strip and relay in Code 4 or 5 |
Lead is ubiquitous on Farnham's older housing stock. Victorian and Edwardian properties typically have lead valleys, lead flashings at chimney stacks and lead bay tops — all of which have a finite service life even when originally well installed.
The north-facing chimney flashings on properties around Hale Road and the older parts of the town centre are particularly prone to failure. Cold north-facing lead flashings cycle through freeze-thaw more aggressively than south-facing work and we see more fatigue cracking on these elevations.
Lead sheet is graded by weight — Code 3 (lightest) through Code 8 (heaviest). We use Code 4 for flashings and valley work, Code 4–5 for flat roofs depending on the span and exposure. Using the correct code for the application is the single biggest factor in lead longevity.
"Had a leak at the chimney that two previous roofers patched with mastic. These guys stripped the old flashing and relaid properly in lead. Dry roof ever since."
"Bay top was leaking into the front room. New lead laid properly with expansion welts. Excellent work, you can see the quality compared to what was there before."
Properly installed lead sheet typically lasts 60–100+ years. Lead bay tops from the Edwardian era are still performing on some Farnham properties. The most common cause of premature failure is incorrect installation — sheets fixed too rigidly without room for thermal expansion.
Often yes. Small splits, lifting edges and failed joints can frequently be repaired rather than requiring a full relay. We assess whether repair or replacement is the better long-term value — and give you an honest recommendation rather than defaulting to the more expensive option.
Code 4 (1.8mm, 20kg/m²) is the minimum for most residential flat roof applications. Code 5 is used for larger spans or more exposed locations. For valleys and flashings, Code 4 is standard. We always specify the appropriate code for the application in our written quote.
Yes — lead is the traditional and most durable material for bay tops. A properly installed lead bay top with correct expansion provision will last 60+ years. Modern alternatives like GRP are also viable but typically have a shorter service life on south-facing exposed bay tops.
Local Farnham roofers. Honest pricing, written quotes, 10-year guarantee on all work.
0125 244 7622 📞 Call Now — Free Quote