Roofs almost never leak through the middle of a tile. They leak at the junctions — where the roof meets a chimney, an abutment wall, a dormer cheek, a valley or a bay window. Those junctions are weathered in lead, and when lead is specified at the wrong thickness, laid in lengths that are too long, or replaced with a smear of mortar and mastic, that is where the water comes in.
Codes and why they matter
Lead is graded by code — Code 3 through Code 8 — with the number reflecting thickness. Each application has a minimum code and a maximum piece length, both set out in Lead Sheet Association guidance, and both exist because lead expands and contracts significantly with temperature. Run a piece longer than it should be and the thermal movement has nowhere to go, so the sheet fatigues and splits along a stress line, usually within a few years. Most of the split flashing we replace was either the wrong code or fitted in one long run instead of properly jointed lengths.
Flashing, soakers and valleys
Where a roof abuts a wall, the correct detail is a stepped cover flashing chased into the brickwork joints and wedged, over individual soakers interleaved with the tiles or slates beneath. Chimney stacks need an apron at the front, steps and soakers at the sides and a back gutter behind. Valleys between two pitches are lined in lead laid over a boarded substrate with correct laps and drips. None of these is expensive to do properly at the time; all of them are expensive to fix once water has been getting into the structure for a couple of years.
Bay roofs, parapets and traditional work
Lead-covered bay window roofs are common on Mansfield's Victorian and Edwardian housing, and many are now well past the end of their original life with splits along the old stress lines. We re-cover bay roofs in correctly coded lead with proper drips, welts and rolls, on a new boarded deck where the old one has gone. We also line parapet and box gutters, which are notorious on older terraces and, when they fail, put water directly into the structure of the building rather than harmlessly onto the ground.
What is included
- Stepped cover flashing chased and wedged, not mortar-filleted
- Chimney aprons, soakers, step flashing and back gutters
- Lead-lined valleys and secret gutters
- Bay window and porch roof re-covers
- Parapet and box gutter lining
- Correct codes and piece lengths to LSA guidance
What it costs, roughly
We quote a fixed price in writing after looking at the job, because roofs vary far more than price lists admit. That said, people reasonably want a ballpark before they pick up the phone, so our roofing price guide sets out real indicative figures for every service we offer, including this one. No registration, no "prices from" that nobody has ever actually paid.