Lead work
Lead is an exceptional material for roof coverings, to cover flat roofs, to line valley gutters and to cover a wide variety of connections between slate/tile work and masonry, chimneys and to waterproof the junction between tiles and brickwork, or tile-to-tile junctions which are vulnerable to penetration by water, such as gullies. A lead 'soaker' is a sheet of lead placed under the tiles at a join, for example, against a wall covered with step flashing to form a waterproof seal. Where terracotta ridge tiles maybe inappropriate, for example on a small porch roof, a hip may be sealed with a 'hip roll', lead flashing wrapped round a wooden pole to give a ridge. A roof is most likely to leak from its weakest point. Quite often this will be where different aspects of roofing styles meet, such as tile or lead flashings.
Lead sheet must be adequately supported on a smooth base sufficient to take the weight and to allow for thermal movement to take place. It may be laid on timber, plywood, concrete or masonry together with a suitable underlay. The lead sheet should be held in position with fixings of a type, strength and position which:
- Support the weight of the lead sheet
- Are resistant to corrosion
- Allow for thermal movement to take place
- Resist wind uplift
Rolled lead sheet to BSEN 12588:1999 is commonly used on all types of modern and historic properties for:
- Flashings to abutments on flat and pitched roofs
- Weathering to ledges and cornices
- Vertical cladding
- Damp proof courses and cavity trays
- Linings to parapet and valley gutters
- Cladding to dormer windows
- Coverings to flat and pitched roofs
- Cappings to parapet walls
- Many other specialist uses, such as radiation shielding and sound reduction.
Tecta Roofing undertake all lead work, from step flashing to box gutters and run out valleys. We can accommodate for all types of lead work ranging from bossing to welding. Our lead work meets the high standard required for listed and period properties. Please contact us for more details.
Frequently asked questions:
What does lead bossing entail?
Answer: Lead bossing is a style of fixing lead to a structure. You use a lead dresser to manipulate the lead and to dress the lead into place. Lead is malleable (that is to say pliable, relatively soft and flexible and able to be beaten or pressed without fracture or breaking). Lead is also durable, if correctly detailed and fixed. It can be worked by bossing (i.e. shaped by hardwood tools) or lead welded – heat fusion welding using lead as the filler rod.
I have a period property, the lead dormer is covered in a patchy, white coating – what could this be?
Answer: In rainy or damp conditions lead sheeting will produce an initial, uneven white carbonate on the surface. This can be aesthetically unacceptable in some situations but, more importantly, the white carbonate can be washed off by rain to cause unsightly staining on materials below flashings. To reduce staining and also provide a pleasing appearance, lead sheet should be treated as soon as practical after fixing and preferably the patination oil should be applied no later than the end of the day's work. It is important to apply a coating under the lower edge of lead work and between the laps.
