Leadwork & Flashings
In Maidenhead & Berkshire
The Detail That Keeps A Roof Dry

Lead is specified by code, referring to its thickness and weight per square metre, heavier codes for high-exposure details like valleys and box gutters, lighter codes for soakers and step flashings where movement and load are lower. Using too light a code on an exposed detail is one of the most common causes of early splitting.

Sand-cast lead is produced by traditional casting methods, giving a slightly textured, uneven surface historically associated with older buildings; it is specified on listed and conservation-area work where matching the building's original fabric matters. Milled (rolled) lead is more uniform and is the appropriate, cost-effective choice for the majority of standard residential and commercial work where matching a historic texture is not a requirement.

Lead expands and contracts significantly with temperature. If it is laid in one continuous piece over too great a length, that movement has nowhere to go and the lead splits, usually along a straight line where it has fatigued.

The solution is dividing the run into bays of a size appropriate to the code and exposure, each with a properly formed lap or welted joint that allows adjoining pieces to move independently while still shedding water. Getting bay sizes right is a specification decision made before any lead is cut, not something corrected after the fact.

A valley carries the combined water of two roof slopes, so it is one of the highest-flow, highest-wear leadwork details on a roof. Lead valleys are laid in bays with a raised welted edge (or timber roll) to prevent water tracking under the adjoining tiles or slates, particularly in heavy rain.

Box gutters and parapet gutters, common on older terraces, extensions and commercial buildings, carry water along a channel behind a parapet or between two roof sections and need adequate falls, outlets sized for the catchment area, and upstands high enough to cope with debris and overflow before it reaches the building's interior.

Soakers are individual pieces of lead woven between tiles or slates at an abutment, one per course, directing water down and away from the wall junction rather than letting it track sideways under the covering. They are concealed once tiling is complete and are only visible if lifted or if a step flashing above them has failed.

Step flashings sit over the soakers, dressed into the mortar joints of the adjoining wall in a stepped pattern that follows the roof pitch, while cover flashings perform a similar role at chimneys and larger abutments, dressed into a raked-out mortar joint and wedged or pointed in to hold their position and shed water clear of the joint below.

A chimney tray (or back gutter) sits behind a chimney stack, collecting water running down the roof above it and directing it around the stack rather than allowing it to pond against the brickwork; undersized or poorly formed trays are one of the most frequent causes of chimney-related leaks.

Parapet walls need lead upstands and cover flashings dressed into the coping to stop water getting behind the wall face, and bay window tops, often flat or gently pitched, rely on lead aprons and upstands dressed against the main roof and window frame to keep water off the timber below.

On homes, leadwork is usually concentrated at valleys, chimneys and bay tops, and matching sand-cast lead is common on period and listed properties where planning or conservation requirements apply. On commercial and mixed-use buildings, box gutters, parapets and larger flat-roof upstands feature more heavily, often over trading premises where access has to be planned around business hours.

On listed buildings specifically, lead specification, code, bay size, whether sand-cast or milled, may be a genuine requirement rather than a preference, and we specify and quote accordingly rather than defaulting to whichever material is quickest to source.